00:02:04 - Meet Today's Guest, Jeannette Loram – Jump to section
00:3:45 - The Horn Article that spurred this discussion – Jump to section
00:10:01 - Laying down some definitions – Jump to section
00:19:15 - The Paper: Results, conclusions, and corrections – Jump to section
00:39:08 - Evolution, adaptation, and more definitions- Jump to section
00:55:28 - Phenotypic Plasticity - Jump to section
01:01:08 - Culture - Jump to section
01:34:40 - Where's Katy? - Jump to section
LINKS AND RESOURCES MENTIONED IN THE SHOW:
More Katy Bowman
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More from Jeannette Loram
Original Study discussed today
The Washington Post Article
PBS on how to read a scientific study for flaws
Time article on Horns
CNN article on Horns
Business Insider on the posture pillow connection
Katy's Live Events Page
Grow Wild Story Submission page
Sign up for Katy’s newsletter at NutritiousMovement.com
Hello! I am Katy Bowman and this is the Move Your DNA podcast. I am a biomechanist and the author of Move Your DNA and seven other books on movement. On this show, we talk about how movement works on the cellular level, how to move more, and how to move more of your parts. As well as how movement works between bodies and in the world, also known as movement ecology. All bodies are welcome here. Are you ready to get moving?
Well, hello there. I am back. But am I back with a horn? That's today's question. You probably heard about or read, because you are interested in human movement and shape as I am, a study out of Australia that examined the X-rays of 1200 Australians between the ages of 18 and 86. The study found that 40% of the people between the ages of 18 and 30 who were X-rayed had, let's say for simplicity, a bone spur growing from the base of their skull. In the media's write up these spurs were referred to as horns. And researchers strongly suggested these so-called horns were the result of the forward head position common to tech uses, especially smartphones. So are smartphones causing us to grow horns? That's today's show.
I’m going to talk about this study, but also the phenomenon of how studies are often reported on. Because it’s fresh, we're gonna break down some of the reporting on this study, as well as the reporting on that reporting, and how it was all being shared and discussed, and if we can even still use that term for what happens in online comment sections. Whether you gave headlines a cursory glance or read multiple articles to get a broader understanding, we’re all affected by this process of information. We all walk away with an understanding based on how we interact with information. What did you walk away from this whole “humans are growing horns” thing?
We also wanted to discuss the process we go through when we read things like studies and reports on studies and what we walked away with. We want to share our process with you because we’re both often asked: “how can I discern good sources of information from others?" "What should I be reading as a source?” or perhaps more importantly, "how should I be reading sources?"
KATY: Dr. Jeannette Loram, hello my friend! Welcome to Move Your DNA!
JEANNETTE: Thank you very much for having me on. I'm very excited to talk about these things with you today, Katy.
KATY: Well we like to talk about these things just any time we're together.
JEANNETTE: It's true.
KATY: And I also think there is a loneliness when you like to talk about them all the time. And maybe not other people like to talk about them as much. So thank you for coming on.
JEANNETTE: Thank you for having me again.
JEANNETTE: Yeah. I was exactly the same. It was a post on Facebook by a colleague and it was the Washington Post article. So that was my first view of it.
KATY: Yeah. And I think that is for most people too. And if you're sitting out there going I have no idea what this podcast is about, I'm going to explain. So The Washington Post wrote about the study, June 2019. And this headline appeared over the story: Horns are growing on young people’s skulls. Phone use is to blame, research suggests. Ok, so that's the story or the article about the study. The study was published in the journal Nature, in February of 2018. The title of the paper: Prominent exostosis projecting from the occipital squama more substantial and prevalent in young adult than older age groups.
So those are different. We'll just start with those are different and I want to sort some of them out. What did you do as soon as you saw the headline?
JEANNETTE: Well, I always scan, I have to say, what the general article was about and then immediately try and find the original paper. Which I would do that with almost anything because I know that it will be a very fun, catchy, spin on the story and it may be quite different in the literature. So that's exactly what I did. Find the article and actually read that and see how it matches to The Washington Post article.
KATY: And we talked about this before. It's very hard to find the original research articles.
JEANNETTE: Yes. Absolutely.
KATY: Because for some reason many journalists fail to include them. And even now in today's hyperlinking society where a link is such a simple thing and all articles are linked but usually to a publication's other writings about it. There is a big resistance, and I'm not sure why, to linking to the source of the study that is in discussion. There are very few publications that link. And it's not only that they don't link. They don't put the title. They'll put something like, they'll put the journal-title and the researcher's name in interview style. But nothing else. So you're just left google scholaring keywords. That's what I do. I use keywords and the journal-title. So I'm trying to think of if we could create a list of steps. So my first step is to try to find before I even really process the story about the article, is I immediately go get the article through googling. What about you?
JEANNETTE: Yes. Absolutely. I've also, I should say, have been really frustrated about this and I don't know why it happens. It's almost, I don't know, I'm maybe casting dispersions but people are maybe reading someone else's article and haven't even read the original article they just maybe Washington Post is the first and then everybody else. I mean then the article is then among a slew of articles and I wonder how many journalists actually looked at the original article. But what I find most often is the most fruitful is to find the researcher on their page on their university.
JEANNETTE: So if you usually, it will say in the article somewhere something like Dr. Smith from the University of Oxford or whatever. So you can google that and maybe something about their field of research, especially if it's a common name. And you find their personal page on the University website and often it lists recent publications. Or if that fails it would be to put their name and a few keywords into something like PubMed or Google Scholar, which will usually bring out what you want. But sometimes it takes you a few times to get it. Horns, if you put horns, you wouldn't - and the researchers name you wouldn't get that on google scholar. It's finding the right words.
KATY: It's because they didn't use the word horns in their research.
JEANNETTE: Right. Horns have nothing to do with bones because horns are made of keratin.
KATY: Right. And I think that that's a very good point. I would say I have a different experience because I am often used as an expert for media articles. And I know that many times people coming to ask me on comments of studies or other things, I'll say, "I can't comment without the study. Could you send it to me?" And they won't have the study. In many cases what they have is a press release on a study ...
KATY: ... which is already simplified and then everyone is trying to kick out a story really quick so they can be timely on it. But it's not, but it's more reporting on the publicity of the piece, not necessarily the piece itself. So I think that's probably key to what's happening in the overall reporting as it's very challenging. Still, I would imagine that most press releases have the name of the actual publication. Just put that in, journalists listening to this.
JEANNETTE: I cannot imagine their press release would not have the paper.
KATY: Although sometimes they're embargoed. I do find that sometimes press releases come when papers are still not out yet, which is an interesting phenomenon itself.
KATY: We could talk about science reporting a lot, but I want to talk more about the mechanics and about the biology. Because I think that we'll just do two shows. Are you in? We'll just do two or three shows. We'll keep going.
JEANNETTE: Oh yeah. Two shows would be good. There's a lot of meat.
KATY: There's a lot of meat.
KATY: So, I wanted to sort out some of the language first. I kind of would like to start with that first.
KATY: But anyway. Researchers use exostosis. Exostosis is the formation of additional bone from the surface of an existing bone. Exostoses are benign, meaning they’re not like a tumor - but benign, because if you look up that word it'll say "benign bone growth". But Exostoses are not benign in the fact that they're not problematic. They're just not malignant. They can still be symptomatic. And you are probably, listeners, already familiar with the phenomenon of exostosis. Because another word often used for exostoses are bone spurs. And one example of common exostoses would be bunions. So if that helps get a framework around what maybe some of the research is saying or what that paper was saying.
Now you have muscles all over your body and these muscles need to attach to something so they can generate leverage. If you’ve ever seen a skeleton - live or even a model or even a picture, I think - you can see that the skeleton itself isn’t really smooth. There are bumps on your bones. They're tiny areas that stick out a bit. These tiny mountains of bone are usually what a muscles’ tendon will attach to. And they are called in anatomy protuberances or eminences. There might be another term too. And I'm not actually certain on the difference between a protuberance or an eminence. It might be the size of it where it gets classified differently.
But anyway, this is important in the HORNS discussion because the paper wasn’t explaining a new bone. I mean it certainly wasn't explaining a horn. But it wasn't explaining a new bone. Rather, the authors were discussing about an increase in length of a protuberance. Something that all skulls already have because it's where you have ligaments and muscles attaching to. And the protuberance they were discussing was the external occipital protuberance. So, external means that it’s on the outside, of the skull, in this case. Occipital is one of the bones of the skull Your skull has got 22 bones including the bones of the face, and there's some variation. But let's say 22 bones. And the occipital bone is the bone in the lower back of the skull, just above your neck. And protuberance just means a part that sticks out. So external occipital protuberance. It's this tiny little lump on the back of your skull where it provides a connection point so the parts that are attached to it can generate leverage to support your head or move your head as needed.
The paper is describing exostosis of a bony protuberance, and (anatomy is so great!) excessive growth of a protuberance actually has its own name (of course it does). And it is, I don't even know if I'm going to say it right. Jeannette, you can weigh in. It's enthesophytes. I think.
JEANNETTE: That's how I would pronounce it.
JEANNETTE: I actually found this a difficult read because of that word that they used way more than they did exostosis. Without defining it.
KATY: That's right. And that's another issue with reading papers that are outside of your field.
KATY: Because if I'm gonna read a paper, even in biology, I feel like I'm having to - Like, I use every field, you say, they coop terms from each other. There's only so many language terms. And when you're trying to describe a phenomenon you're reaching into the same pot of language. Sometimes you create new words. Sometimes you put a bunch of Latin words together to describe a phenomenon. So they don't always mean the same thing. But they want to clarify because some bone spurs happen on smooth bone. And that has its own name. I feel like I could be googling a lot of language. They have their own name and I feel like it's like an enso... do you know what it is?
JEANNETTE: I was actually very confused by what, by this fact that they were talking about enthesophytes but the abstract in the title had exostosis.
JEANNETTE: And what I discovered, again by googling, these are definitions that I found that the enthesophyte was an abnormal bony projection at the site of the attachment of a tendon or a ligament. And then osteophyte was an abnormal bony projection in the joint space.
JEANNETTE: So my interpretation was that exostosis was the general term.
JEANNETTE: But the specific terms were enthesophyte and osteophyte. Does that make sense?
KATY: Yeah. So osteophyte is the other term I'm looking for. So exostosis is, to me is the growth of it.
KATY: And the sub-classification of an enthesophyte or an osteophyte is more the location of that growth.
JEANNETTE: Yeah. That was exactly my interpretation.
KATY: And I think that the reason they have a different language is ... Levers aren't - they're not equal in length. I mean nothing is equal when you consider ... equal is not the right word. They're not exactly the same shape because your bones are being created by you as you move around. And so people who move in different ways would need different lever lengths. Or lever lengths are all different. And I think of bony protuberances as levers. They are shorter than the long levers of, let's say, the humorous or the femur. But mechanically speaking their function is the same. They're there for leverage to generate torque. And so I think it's helpful to have when you're measuring something that is bearing greater torque than say the surface of two bones that there would be a variance of it. So the fact that there are two terms makes sense to me. I think that bone spurs are probably more osteophytes. The way people are used to thinking about it - your problematic bone spur would be an osteophyte. But I would not say that a ... I mean what is a bunion? Is a bunion then an osteophyte? Probably.
JEANNETTE: That's a good question.
KATY: Yeah. But I don't know. And the thing about exostosis is, there's a mechanical process to exostosis. It doesn't mean that it's the only way that it can come about.
KATY: But the easy way that I explain it is when you have things pull on your body quite a lot the excessive pull - and excessive is relative - but let's say that more than the load that you create regularly through repetitive movements. It needs to, the tissues involved in those motions need to beef themselves up so to speak. They have to diffuse the load better. So, they can do that by changing shape a little bit. And then there's also maybe some protective features. There's maybe not only one feature - not only one problem that exostosis solves but in general the understanding of it is you're mechanically loading it so much that it has to change its shape to deal with the burden. And the paper was measuring 1200 skulls and saying this lever is longer but it wasn't only that it's longer. So the lever length seems to change in people with age.
JEANNETTE: Well ok. I thought the paper was interesting. I think it's biggest letdown was its results. So I read the introduction. It had some good premise. It had a good premise. And then I got to the results section and it didn't seem to add up. It has a very very short results section. So in a scientific paper, there's always a wordy description of the results and then there's always some figures. Or there's almost always some figures. And if you actually look at the results and their conclusions from those results, it doesn't add up. And the figures don't match the word results.
JEANNETTE: So, I think there's a really big issue with that and I imagine Scientific Reports which is the journal it was published in, has been in contact with the authors to get a correction done. And it will be very interesting to see what comes out in terms of a correction. So, what happens if something comes to light or is incorrect or doesn't make sense then a journal or authors can publish what they call a correction. Now I haven't seen that come out yet. So it will be interesting to see what comes out. Because one of their biggest conclusions was that males were 5.48 times more likely to have what they called an excessive protuberance than females. But that's not borne out in their figure 4, which if anyone actually looks to the figure, it doesn't matter if you do or you don't. But they actually look, males and females look very similar. So, and I think the figure is probably wrong. Because it seems to be as a general rule it seems that these protuberances are larger in men in general. And I think that they're actually used sometimes in anthropological studies to differentiate skulls between male and female.
KATY: That's right. That's right.
JEANNETTE: So it would seem to me that they probably just made a mistake in their figure. But it does, obviously, mean that it's very hard to draw conclusions when one of their main figures is incorrect. And I kept rereading it thinking "what am I missing?" And then realized I wasn't missing something. It was just obviously an error. So that was a big thing for me. There were also some suggestions in it which seemed almost too small to be relevant, really. I don't know if you saw that, Katy, where they talk about, this is particularly in relation to forward head. So in the paper, we haven't mentioned this yet, but they were basically doing some analysis which showed that one of the main determinates in having what they called excessive protuberance was being male and the second thing that had a significant effect was the degree of forward head position. Katy, you might be better to explain that phenomenon than me but it's essentially what we think of as that forward head of forward of the shoulders position. And they were trying - they were suggesting that that was significant in predicting whether you have one of these protuberances or not. But the relationship seemed very small. And to me would seem almost insignificant. But they claim it's significant. So I would have loved to have seen a raw data - like a data table.
KATY: Right. And that was one criticism. They didn't include any data tables.
JEANNETTE: No. So it was really hard to really know whether their data is valid. And it will be very interesting to see what comes out in the correction. Because I think some of it was just a mistake. That was a real concern. And that's something that I, going back to our original topic of how you would read a scientific paper, it would be quite thorough reading of the results and looking at the figures and looking at the conclusions and seeing if it makes sense. And that can be quite hard to do sometimes.
KATY: Yeah. Do you think it's practical for folks to learn how to read scientific papers without - I mean it's not really.
JEANNETTE: No. No. I actually don't. I think it's... I mean this paper is not ... I mean it's easy for me to read the results section because I have enough experience in statistics and data presentation, but I found some of the language challenging because it's not my field of expertise. So I had to do a bit of digging around. But I think someone with no background in science, it's nigh on impossible. Because articles are written - scientific articles are written they say for peers. So what that means is you are writing assuming that the person reading your paper has a similar background to you.
JEANNETTE: So if you are a molecular biologist you write in a language that another molecular biologist would understand without much elaboration. And it's the same with this paper. It would have been written for other chiropractors, maybe other anthropologists, or biomechanists. That kind of maybe physiotherapist. But it's not written for people to be able to really understand without a significant amount of background. And I think that's a problem with how science and research are actually conveyed to the general public because often they're of great interest to the general public but that's not transmitted in a very effective way. And that's probably another topic for another day.
KATY: Yeah. So it's - I can keep talking about this paper from the mechanical, as you said, it's been identified for, I would say for a while that there's a variation in shape of these protuberances. So I think the fact that there was a variance in shape of the protuberances like my personal interest is in how we process information about movement. Not only how we move but I spend so much time studying movement, at this point, I'm probably more interested in studying sedentarism.
KATY: Because I feel like if you approach the movement phenomenon - we're more sedentary than we move so, therefore, it seems to me that the phenomenon of sedentarism needs to be investigated more thoroughly. So I feel like that's kind of where I've taken my study of movement to - to start to look at why are we so sedentary. What are the mechanics of a sedentary person besides just not moving? But then what are all the things that come into that. And then it goes up to the cultural level which would just be large groups of people not moving. And how do when we have this dual role of kind of a group of people moving towards the scientific process as a way of knowing and understanding the world, it still doesn't help us really make decisions in a particular way. It helps us maybe know some of the facts. But we don't necessarily move more because a study has come out showing that we should. You know what I mean?
KATY: It's not the only compass for behavior if you will. But I was interested in how it seemed like all of the reporting of this paper seemed to be more with the intent to dismiss it as a whole, full stop versus what we're doing now which is what I do when I read anything - which is to pull it up and to take the pieces of it that are clear and sometimes that is only the data that's gathered. Which in this case wasn't fully included in the study. And then you can see what the flaws are and then read the criticisms. That's another one of our steps, hey?
JEANNETTE: Absolutely. Yeah.
KATY: let's say that reading the paper - you can go read the paper. And I would say that oftentimes this is the problem with paywalls, is you can't actually access the paper.
KATY: In many cases. So your ability, even if you could read the data through your training, you'd have to pay $30 or $50 to be able to see it.
KATY: And like, who cares. There's so much going on to read about and you're not making any money by doing it.
KATY: So paywall, and the fact that science does influence - understanding influences our lives - but that it's not accessible for everyone to have the ability to process it. That's an issue. But let's say that you pay for the paper. How do you pull out the things that you need to mull on? Or how does someone reading this shape the next research better? And I feel like this - this is their second paper on this. Is this right?
JEANNETTE: Yeah. It is. They have got, which I think was an earlier paper, and it was just on the young. Just the young people.
KATY: Right. And I think one of the criticisms of that early paper ... if you don't know, papers are just, they're like one tiny piece and you're collecting lots of pieces together and you do a paper and then people criticize it. And criticism I don't only mean in a negative way. If you pull out the issues with it. And I believe this was their second attempt to meet some of those earlier criticisms which is "Well you didn't look at a larger group to compare." So then right, they did this. And then there will be more criticisms and they will likely go back next time. And one of the criticisms of this paper was the entire population was from one chiropractic clinic. Meaning that every person who had - every person who was measured had been seeking treatment. So that's a particular filter, right? That's not necessarily the general population. And that was one criticism I would say from the media on this paper - these are people who are all, let's say generally, they all have neck pains. So it could just be that people with neck pain have larger protuberances and that's why they're there. Although in the paper itself they were saying that they, people go to chiropractors for various things. I think that this was a large database of existing imagery that could just be reviewed.
JEANNETTE: Yeah, I think it was - they hadn't necessarily gone for neck pain.
JEANNETTE: So it could have been they were in the chiropractic practice but they could have gone for something to do with their foot.
KATY: And they eliminated people who specifically had cervical issues. So it's just sometimes if you read a piece that's intending to dismiss it and it's well they were all from a chiropractic clinic and the authors didn't think about that if you actually read the paper they did. They did note it. And they did the best with their population. And a lot of the criticism, this is kind of going on what I noticed a lot was there was a lot of scientific criticism about horns.
KATY: But the paper didn't include horns.
KATY: And the researchers never used the word horns and so a lot of people were criticizing The Washington Post article as if it were the research article. And if you are a layperson and you're reading this and you don't know that horns wasn't the theory or part of the presentation of the paper, then it's easy for you to just dismiss what's going on in this piece full stop because. I keep saying full stop because I'm talking to you.
JEANNETTE: You can carry on. I don't think anyone will mind.
KATY: Ok, thank you. You know to me it was a little bit confusing. What are you talking about? Are you trying to take the paper bullet by bullet or are you taking the Washington Post article which, as you said earlier, might have been the main source of information for the journalists writing subsequent articles?
JEANNETTE: Yeah. Absolutely.
KATY: Which is a problem.
JEANNETTE: It is a problem. I have two points. One is about what you were mentioning earlier about limitations about the study due to their sample size, etc. And I think it's not a helpful criticism. They're actually reporting something that they presumably observed in their population and thought it was interesting enough to actually study further. And that's how science works. You have a little bit of information and you build on it. And I would hope that lots of people would take this study now, because it has produced an awful lot of interest, and actually say, "Right well we have huge numbers of both fossil remains of skulls and we have collections from various hospitals" and you could start doing much bigger studies to see if this is actually more of a general phenomenon. And the other thing that I saw in a lot of the criticisms which is a fair criticism to an extent in that you can't say anything about handheld devices because you know nothing about the population of the people that you studied and their habits. Which is true. But the authors at no stage stated that this was definitively ... this was a suggestion on their behalf. So I think again, it's a fair criticism in that you can't determine if there's increase in the size of the protuberance is generally occurring in younger people, you can't relate it to handheld devices because you have no idea of what the handheld device usage is of your particular population. So that would be a different study. But I think it was a little unfair because they were suggesting a possibility. They weren't actually stating it as fact.
KATY: I think they were trying to make it relevant.
KATY: I feel like that was the intention. And again, if you go back to the headline of the Washington Post, you know it says, "phone use is to blame" research suggests.
KATY: And I guess you could say that there was a suggestion of a mechanism, but I don't - again we're just focusing on the article. But I like that they wrote down some of the forward head activities: The head is in front of the body for a lot of things, driving and cycling and all these pieces.
KATY; But this is a possible explanation for why we would see a phenomenon that has been observed medically in older people now in younger people. So the understanding of where they come from, these protuberances, changes in size, may need updating. I didn't take any issue with that because I feel like I probably would have done things a little bit differently just because of my mechanical background which is different from a chiropractor.
KATY: I would consider loads more. But that's how everyone feels about every paper. You look at it from your field. And so now maybe some biomechanists can take this paper and then maybe you'll see anthropologists take this paper and build on understanding from it. That's the way it works. That's what these papers are for. We're a large group of people with different observations within populations and then you're sharing them and then you're developing them.
KATY: So, let's switch to what do you think ... horns, I feel like horns was very clickbaity. I feel like horns tend to go - they tend to just pull up visions of demons.
KATY: You know what I mean? The demonizing of handheld devices or technology or "Look, now we have horns." I'm not even sure it was not on purpose that it was done that way. But there was a huge reaction. A big reaction to this idea that this idea that technology would be harmful to us. And a lot of pieces that I read were moral pieces. This is just another paper trying to make the fact that we use technology so much - a moral issue. Look we're ruining our kids. They have horns now. Instead of just trying to take the emotion out of it just to say, "Hey are there changes to our skeleton in some particular way." So I liked the criticisms where they were more here's the problems but the phenomenon is definitely worthy to look at even further.
KATY: My big thing is, I didn't want this for people who only read the headlines to go, "Well that was debunked, right?" I hear people say that all the time. "They debunked that." And it's like, No that's like a battle of the media clickbaity things and then it just falls away. The interest in the phenomenon because it's just this emotional roller coaster. I felt like this was really important to those who are interested in the impacts of movement, posture, positioning, alignment, culture. I thought it was worth a discussion because I think it's very interesting and totally relevant. What I saw though was this idea that now our future generations are gonna have horns. You know what I mean? That we are evolving. Or I think I saw a picture, you know the typical picture of someone coming out and growing out and at a computer and a horn, now the horns are on the end.
KATY: As I was talking about it with other folks - this idea of morphology. Morphology - the study of shape and what shapes us. I love morphology. I've always said that your skeleton is - it's an autobiography of sorts. Because you're writing it. But it doesn't necessarily mean that things are handed down. So I just thought it would be a really cool place to talk about why this is not that case.
KATY: How do we talk about morphology and culture. What are genetic changes? Adaptations? Evolution? Let's talk about some of the selection process so, what do you want to start with?
JEANNETTE: Ok. So these are really complex and big topics. I'm gonna try and I think we should go step by step.
JEANNETTE: And define things so that people can try and easily separate them out. And it can be challenging. Evolutionary biology is probably one of the hardest literatures to get into. So I think we should start with defining evolution. Natural selection. What different people mean by adaptation. And then bring in some culture. Talk about the role of culture and gene interaction.
JEANNETTE: Does that sound like a sensible path?
KATY: That's great. And plasticity.
JEANNETTE: Plasticity would be good. So we'll define all those...
JEANNETTE: ... so if you ever do want to look at papers you will have a clear idea of what biologists mean when they say certain things and also just to see how different the mechanisms are within an organism's lifetime versus when we're talking about evolution and passing things on.
JEANNETTE: So I have a lot of words at this stage. So I think, Katy, if you want to interrupt me at any point with a question or something that doesn't make sense, please feel free before I go on a horrible monologue.
KATY: Right. And I think I will interrupt with this idea of what would a listener - what would their question potentially be.
KATY: It does for me. Everyone out there?
KATY: It would be so nice if we could do Romper Room style.
JEANNETTE: I know. Hands up!
KATY: Is that good?
JEANNETTE: So that's evolution. So when we talk about selection - this gets a little bit more complicated. So I should say one thing first; evolutionary changes can occur both by what we term selection but also by something, by chance. And that's something that people don't often realize. So the term that evolutionary biologists use is genetic drift. So evolutionary changes can occur just by chance through this process of genetic drift. And I say that not to confuse matters further, but just so that you might see that term, and we often don't realize that some changes just come about through no selective forces at all. It's just random chance. So it would be - I'll give you an example. Again, if you have 10 red ants and 10 black ants, very tiny population. And one day a deer runs through a forest and it stands on them and it stands on 7 red and 3 black. The population would be then skewed toward black ants. Not through any difference in their biological function but just because it was dumb luck. So a lot of changes that we see are not necessarily selective. So that's just to put that aside.
KATY: And then, let me just pop in here. So dumb luck, I'm trying to think of examples of dumb luck. I love your deer example. So just like natural catastrophes. Are those dumb luck.
JEANNETTE: Yeah. And those effects are much greater obviously the smaller the population. So human beings would have, back in the day, when we lived in small tribes, had pretty small populations.
JEANNETTE: So there could be a natural disaster and it's just chance.
KATY: It just left everyone who had one thing.
JEANNETTE: And I think people forget that that's sometimes there's no rhyme or reason. It's just a sampling error if you're a mathematician.
KATY: Right. It's hard not to attribute purpose to everything. It's really challenging.
JEANNETTE: It is. Which is really interesting because often people think natural selection is purposeful. But it's not. It's really mathematical. It's not purposeful.
JEANNETTE: I'll try to explain that next. So natural selection, this is of Charles Darwin fame. So individuals with heritable traits - so that means characteristics that can be passed on. So individuals with heritable traits that favor survival and reproduction will tend to leave more offspring than others without those traits, causing those heritable traits to increase in frequency over generations. Again, that sounds like a bit of a mouthful. But if you go back to my example with the hemoglobin, there's something which everybody has probably heard of which is sickle cell anemia. Now sickle cell anemia can have some quite serious consequences. Your red blood cells, there's a very simple genetic change which results in a change in the structure of the hemoglobin molecule. And what it means is your red blood cells become sickle-shaped. They are actually more apt to burst. They're very fragile. So anemia can result along with other things. But, like I said, they also confer resistance to malaria. So in populations with high malaria, those traits would have resulted in increased survival and reproduction. So they tended to leave people with that mutation or that genetic change had more offspring and over a period of many generations, those characteristics increased in the population.
KATY: I'm just going to restate it a little bit more simply. A sickle shape to a cell is an asset in areas with malaria.
KATY: So because it's an asset, if you had the non-sickle shape, you would have more people not surviving malaria.
KATY: And so those with the non-sickle shape would die off or not make more people.
KATY: And then so what you do, is you end up over time having people with the sickle shape being successful in that environment, having more babies who have the sickle shape, they're more successful. And then over time what happens is you have entire populations that share a particular trait because that trait works well in that environment. It's not an optimal trait. It's always relative for an environment.
JEANNETTE: That's right.
KATY: I just wanted to restate it simply.
JEANNETTE: That was way clearer than my definition.
KATY: I like both. I like both. I think there's just different types of - there's people listening with different backgrounds and...
JEANNETTE: Yeah, and I'm sorry I always talk as a biologist.
KATY: You should. You're a biologist.
JEANNETTE: It's something that I cannot get away from. That was great. That's exactly what I was trying to say in much harder words. But also, as a good example, when we look at that trait in an area without malaria, there's no benefit to it. It's actually costly. So that trait probably occurred in other populations around the world but essentially there was a negative selection when that happened. Because natural selection would favor its removal from the population when malaria is not present.
KATY: Right. So that would be a drift?
JEANNETTE: No. That's still selection.
KATY: I mean the fact that there's a randomness to sickle cell's coming on.
JEANNETTE: Ok, so no it's not drift. I'll explain what it is.
KATY: So let me just sum up the part that is... I'm just kind of checking my own. So someone else for a reason you're about to explain, had sickle-shaped cells in an area without malaria. They wouldn't necessarily survive better. In fact, it would be more of a liability.
JEANNETTE: It would be the opposite, yes.
KATY: It would be the opposite so you would find people with a non-sickle cell reproducing more and you would see fewer and fewer sickle-shaped cells in folks and then you just end up in a population that has very little of that occurring.
JEANNETTE: Exactly. Your question relates to the mechanism of change. So for natural selection to work, it has to select something. So there has to be a variation in a trait. So in this case, some people have sickle cell red blood cells and some don't. And that occurred because there was a mutation.
JEANNETTE: At some point. In somebody or in several people there was a mutation. And mutation is a change in the genetic code. And it can be for a number of reasons that not everything is perfect in biology and mistakes happen. It's essentially a mistake that happens in the copying of DNA. And that change occurred presumably in one or more individuals. And then over many of hundreds or thousands of generations, the selection in the malaria areas happened. And conversely, if one of those mutations happened in a population without malaria, it would stay very low or be removed entirely because it has a negative effect.
KATY: This is a question that just pops up. Why is sickle cell shaped a mutation and not the non-sickle cell?
JEANNETTE: We're getting philosophical, I feel.
KATY: Is that what it is?
JEANNETTE: Who knows. Well, actually they probably do know. I don't know. But there would have been an ancestral, what they call an ancestral hemoglobin shared way back. Mammalian lineages all have hemoglobin. So what the ancestral hemoglobin looked like, I don't know. But there would have been mutations through, you know that hemoglobin that we've got today is probably started back in the third generation of homosapiens. So what is mutation? They're all - you know, we're the result of millions of mutations.
KATY: So it's relative.
JEANNETTE: I think we always look at mutations as being a bad thing.
KATY: Sure. And it's not. Well, the word implies...
JEANNETTE: It's both. It can be positive. It can be negative. It can be completely indifferent.
KATY: You've got horns on your red blood cell.
KATY: I was just thinking that malaria, jungle areas, would have been where we mostly came from.
JEANNETTE: Um. Well...
KATY; And that's just a very shallow assessment out of the top of my head.
JEANNETTE: I think - if you look at Savanna. The hypothesis, these changes all the time. But a Savanna origin, which is actually quite dry.
KATY: Ok. Ok. All right.
JEANNETTE: If you're looking at West Africa it's very very wet. And so actually I would say that we probably didn't. I mean, I'm guessing here, but Savanna is probably dryer. Probably not so malaria rife.
KATY: I guess I was thinking more like, you know how when they talk about mathematically speaking the way that bees shape their cells optimizes, optimizes the volume.
KATY: This is a terrible, off the top of my head, me making stuff up. So let's say that there is a mutation and for some reason, you have bees that shape their cells differently. What would make one survive more than the other is simply volume of food, right?
KATY: Or do what we consider to be - I mean I would assume that as bees are turning into bees from whatever else they evolved from there might have been lots of different shapes of honey storage or do you think that full volume was always the first piece. Or if the shape evolved to be that and that's what's perpetuation. The way I'm thinking about it is, is there something about the non-sickled hemoglobin shape that maximizes oxygen transport.
KATY: So I'm thinking about it as a mathematical shape thing where we would consider the mutation one that carried and let's say does its job as a red blood cell with less volume and that's why it's considered a mutation. Even though it's an asset.
JEANNETTE: Yeah.Maybe. I think probably people have actually done these studies and I don't know them. And they've looked. I mean it's certainly almost everywhere else there is no sickle cell anemia. Apart from now obviously we have more migration which actually is interesting because that can change things too, right? That the ancestral form was a donut-shaped red blood cell and that shape has various benefits. Volume. Maybe also smooth movement of the blood through the vessels.
KATY: Right right.
JEANNETTE: Less blockage. Because I know sickle cell can result in blockage. So I think there are lots of things that would mean that anything that changes the donut-shaped blood cell would be a negative thing and people talk about it as a mutation because it's something that has arisen more recently in the human lineage. But I still don't think they refer to mutation because it's negative. It's just important to consider. It's just a time thing rather than the fact that it's a negative thing. Because plenty of mutations have obviously resulted in very positive effects.
KATY: That's right. I think it's more like, for this idea of alignment, there's this idea of a shape optimizing. But that's also in the context of the environment in which you're in. And I'm thinking of things much larger than this show right now. But it's important for me to always reconcile the different pieces. So there are mutations and the mutations are beneficial. Just as there are different shapes to skeletons and they pay off in some places and they don't pay off in other places. And it's all context-driven. It really is all context-driven.
JEANNETTE: Yeah. Absolutely.
KATY: Sorry for that sidebar.
JEANNETTE: No. It was helpful, I think.
KATY: Hopefully. Raise your hands, everyone. Was it helpful?
JEANNETTE: Again, raise your hands. Ok, so we have, we've done evolution and natural selection. And I think another point that I want to make about evolution and I think this is quite relevant to the paper that we're discussing about the morphological change is that evolutionary changes tend to be slow. So it takes hundreds if not thousands of generations from a change, sorry a mutation, to go from low frequency to high frequency in a population. Even with strong selection for it. Because you - stay you start with a population of a thousand people and one person has a change, has a mutation. Obviously, you've got the other 999 still having babies, etc. So it takes, even with a strong selective advantage in that...
KATY: There's still only one of you.
JEANNETTE: There's still only one of you. So when you're talking about population changes takes a long time. So that's one important point. So now, I'm gonna talk about the word adaptation. Which I think is very challenging. Because it's, like we were saying earlier, there are words. It's an old word. It's been around hundreds of years. And it's been co-opted by biologists in different ways. I would say that all biologists really use it to mean a process by which a species becomes fitted to its environment. But an evolutionary biologist would probably use it quite differently to maybe a physiologist. And this is when things become messy. So an evolutionary biologist would often imply by that term genetic adaptation.
KATY: No. It sounds great. We're gonna get it on hats and you should sell them on your website. Phenotypic plasticity.
JEANNETTE: So phenotypic plasticity essentially means the ability for an organism to express different characteristics depending on the environment. And that doesn't necessarily have to be positive in this case. So a great example is amphibious plants. It's quite an extreme example. So you have amphibious plants that grow partly in water and partly out of water. They have the same genetic information across the whole plant, obviously. It's one plant. But they have different leaves below the water and different leaves above the water. So it's basically they're able to have a completely different phenotype. So phenotype is the observable characteristics of an organism. So if someone just took a picture of the top of the plant, and showed someone a picture of the bottom of the plant, they would look like two different plants, but they're the same. So plants tend to be much more plastic - more flexible. So all of this might be a bit complicated.
KATY: Well let me just ask a question first.
KATY: If I have one arm in a cast for let's give the extreme 3 months. And my left arm and I'm vigorously working out my right arm and I showed you my two arms are there phenotypes different?
KATY: Ok. That's just to ground it in what we're talking about. So I can have different phenotypes of arms on my body. And I can also have the before picture and an after picture of my entire body and there will be change in my phenotype, let's say if I started running or whatever.
JEANNETTE: Yeah. Absolutely. Muscle. And that's where you see physiologists use adaptation a lot is muscle adaptation. And what they mean is it's not anything to do with genetics. It's just that every organism has a degree of flexibility to respond to change.
KATY: It's your viewmaster for Move Your DNA.
JEANNETTE: Yeah. It is.
KATY: To go for a completely outdated 1980s reference that will be totally obsolete in 7 years from now.
JEANNETTE: It will. I mean have your children seen one?
KATY: No. But I write. I'm such an 80s child. "Everyone will know what this is."
JEANNETTE: I know. True. I was explaining to my eldest son what a VHS tape was today.
KATY: Right Right.
JEANNETTE: Oh my goodness. So another human example which is easy to see on a longer time scale, because I think sometimes you see changes over generations and people think that it's genetic. But most populations are taller now than they were 100 years ago. But it's not - and ok there are several generations have gone by but it's not a hereditary change.
KATY: It's not a genetic change.
JEANNETTE: It's likely just diet. So your phenotype is responding to improved diet. It's not responding to inheritable change in human beings.
JEANNETTE: That's phenotypic plasticity. So in the term adaptation, I think I would prefer to see people clarify genetic adaptation versus phenotypic adaptation. So if anyone's listening out there who writes papers, for the sake of everyone...
KATY: Or blogs. Or even blogs or anything that's informing. How about the Washington Post. If you're listening to this...
JEANNETTE: There you go, just clarify what you mean.
KATY: And I also think in exercise, we use adaptive exercise typically means that you're modifying something. I think that adapt is being used, and I use it too this way many times just casually, is this idea that you're changing an element of something. Still, it's original, but you're changing an element of it. And that definition might hold all the way through. But it is confusing when adaptation means process.
KATY: For many. When the term is loaded with a process and a mechanism, it makes it challenging to hold a conversation and this is also why I put that at the end of Move Your DNA because there's so many important discussions that need to be had right now, but we're all using the same words with different definitions. And it's very confusing. So just starting by "how do you use that word" and "what does that mean" and then I think that many arguments are sorted out when you spend more time asking for clarifications to someone else's point rather than just trying to defend your own without understanding.
JEANNETTE: Yeah. Because you might just be talking about two different things entirely.
KATY: So many times that what it is.
KATY: I think culture is important because I think that the horn thing, I'm going to call it the horn thing forever - thanks Washington Post. I think there was a visceral reaction to this idea that where we are right now that feels so inevitable. So I'm at the end, or maybe now, when you read that people are growing horns (they're not growing horns) but when you read that, there might be something left in our skeleton that tells a story about how we held our body. And I just have to do this, remind me to get back here because ... One cool thing about research papers is that there's a comment section on research papers many times.
JEANNETTE: Yes. Yes, often, yes.
KATY: To me, that would be my second thing. So you know, you're reading The Washington Post and then maybe, if you're not comfortable with papers then you want to read all the other opinion pieces and you start to pull things out. But eventually you have to go back to the original source or it can all just be people arguing about reporting and not arguing about research. When you get into those sections you can see people who are peers, many times, point out pieces or refer you to other things. So that's gold as well.
JEANNETTE: Yeah, that is very true.
KATY: That's another place for more perspective.
JEANNETTE: Yeah, And also particularly in, I would say, the journals with high impact. So just to clarify, so there are, with scientific journals and other academic journals they have what's called an impact rating. So the impact is how many people read those papers and value them highly. So highest impact journals: Cell, Nature, Science. Those are the big three guns. And then there are lots of other proceedings from the Natural Academy of Sciences. Highly regarded journals. A lot of people read them. A lot of very clever people in different fields. And they will often write letters. And particularly if a paper is contentious, researchers will actually write to the journal and those letters will be published and then the authors will respond to those letters. So that's also - and they tend to be a little bit more technical. So if you are a little more technical and an article is particularly important but perhaps not toeing the line. Being quite radical in their views. You'll often get letters and those are really interesting to read.
KATY: It's helpful. I think that discussion between two people who see things differently is where new hypotheses come from.
KATY; You need that back and forth. Very important.
JEANNETTE: And they can be very entertaining sometimes.
KATY: Oh it's great.
JEANNETTE: It shows that scientists can actually have a bit of fun.
KATY: They do. They do. In one of those letters though I had read something akin to "well if a forward head, the weight of the head being forward, would cause an increase in the size of the protuberance, then we would expect to see four-legged animals to have much larger ones."
JEANNETTE: Oh. Right.
KATY: And I just thought that that criticism to me was a challenge. Immediately made me think of a bison. An American bison.
KATY: Or any other animal whose anatomy has developed over a much longer time. Where you look at the vertebral bodies and the dorsal extension of the vertebral body...
KATY: ...being so long to generate so much leverage. I just thought it was ... you just have to take everything with a grain of salt. Because not everyone who is commenting on a paper knows mechanics.
JEANNETTE: No. Absolutely.
KATY: Not everyone knows biology.
JEANNETTE: I remember seeing that and thinking how ridiculous because you've got so many different structures.
KATY: Right. It was just one of those things like going, yeah but, in something that has been on its hands and knees with its head out in front for millions of years, there is an evolved shape to those things.
KATY: So it's just part of the thing with why I'm interested in this idea of a shape that optimizes function. Although again, that's modifiable based on context.
KATY: You have to have some parameters around function and this idea of adaptation - is that the right word to say? It's this idea that the human body can just build muscles to tolerate whatever it does. Rather than, I think what the authors of the paper and what I'm just trying to explain through my own work which is there's costs to some of the things that we are doing.
KATY: Physically. There's cost. And if you're trying to figure out why there's a rise in cost or a rise in need to deal with our structure it might relate to these things called the mechanical laws and how your phenotype adapts to the mechanical environment in which you are in. I made that change just for you. Just so you know.
JEANNETTE: Thank you.
KATY: That was the first time that's ever come out of my mouth. It probably was in Move Your DNA but... ok so, culture. Culture is very important. This is about culture. This is about, I think, a population of people not recognizing that culture does influence phenotype.
JEANNETTE: Yes, absolutely.
KATY: And evolution.
JEANNETTE: Yes, and actually some people think that it's the thing that is actually is the major driving force for modern - or evolution in modern human beings. So I think a lot of people have an idea about evolution and natural selection and they think about an animal adapting genetically to this very external environment that they have nothing to do with. So there's kind of hostile environment, it's temperature, it's pressure, it's humidity.
KATY: It's lions chasing...
JEANNETTE: It's lions. It's diseases. But your environment can be very much modified by you. By your culture. So, you can change your environment. Lots of animals do that. You know, nest builders. They change and modify their environment. And I think a lot of people also think that modern human beings aren't evolving because we're kind of separate from the environment.
KATY: We made it!
JEANNETTE: We made it. We're now in our boxes. We have medicine. It's just that the selective forces now may be very different to when we didn't have all those things protecting us from lions and diseases.
KATY: We are really making the pressures now. The pressures are things that we're creating.
JEANNETTE: So the classic example of culture is - which I think examples always help people to visualize.
JEANNETTE: So the classic example is lactase persistence. So lactase is the enzyme that breaks down lactose which is milk sugar. So back 20,000 years ago, whenever, when all human beings were all living hunter-gatherer lifestyles, all human begins pretty much lost the ability to digest lactose shortly after weening. So in childhood. And still today, probably the largest proportion of adult human beings still do not digest lactose - milk sugar. So then around 10,000 years ago in some areas, we start seeing animal domestication and dairy. And actually, it seems that people started to drink milk first before any type of adaptation happened. So since that process, the culture changed. We went from populations that did not have domesticated milk-producing animals to having those. That was a cultural shift. And people started drinking that milk. And then in some, actually in different populations, there were slightly different mutations which enabled adults to continue to produce lactase and break down milk sugar. Because that was such a strong selective pressure because presumably there were loads of different benefits from drinking milk both in terms of growth, age to reproductive maturity, probably being able to ween your children much earlier, etc, etc. So that had a very strong effect on what's called your reproductive fitness. So we see that, and still, so that was a very strong selection pressure. It still took almost probably 9000 years to become to the levels it is today. So now, in lots of parts of Europe, the middle east, people now buy and large are what's called lactose tolerant. They can, their lactase enzymes persist and they're able to digest the milk sugar. And we call people that can't lactose intolerant. And there were plenty of those too. But they're much rarer in the populations that have been dairy farming for a long time. So that's a very classic example of a cultural effect. A gene-culture interaction. So we created the selection pressure by starting to drink milk.
KATY: Yeah. I'm just nodding.
JEANNETTE: That was a sigh. That was a big sigh.
KATY: Well I think there's just this idea that nature, and I think culture is often put under the word nurture because nature/nurture sounds cute. It's like nature versus nurture is often the head to head battle. But it's really nature via nurture. And also nurture via nature. They're constantly informing each other.
KATY: One shapes the other and that's why that's ...
KATY: ... that's the story.
JEANNETTE: Yeah, absolutely. Even things like sexual selection is huge. And that's a - we all choose our partners perhaps in a much more culturally informed way. You know what was attractive in your partner thousands of years ago might be different to what it is today. And that clearly has an effect on reproduction. So there's loads of things that, yeah, culture is huge in terms of it. And gene-culture interaction is a hot topic, I think, in evolutionary biology. Because really I think lots of people think it's a major driver.
KATY: It's very challenging to parse the two.
KATY: So yams. I sent a link in our last newsletter about the sickle cell anemia and yam farming. So we've already talked about the selection, the mutation of sickle cells, but why it worked, why it persisted, had a lot to do with the culture of the group in which it mutated. So do you want to talk about that?
JEANNETTE: Yes. So I haven't read so much on this but basically, yam farming involves creating - well - standing pools of water results when you grow yams as I understand it. So you are basically creating environments for mosquitos to breed and flourish. So malaria rates presumably increased. So it was essentially the cultural activity of yam farming increasing the number of mosquitoes, which increases the likelihood of getting malaria. And then the trait followed along behind that cultural process. So you saw the increased gene frequency or appearance of sickle cell anemia in those populations. And that was in Africa. And you also, interestingly, there is apparently something going on in Asia with tire production.
KATY: That's right.
JEANNETTE: So they're producing tires and I can't remember where it is in Asia. So the tires create a ...
KATY: Extra surface area.
JEANNETTE: Extra surface area that collect water and the mosquitoes can flourish there. It was interesting because, as you know Katy, I lived in Bermuda for a number of years. And Bermuda suffered quite a lot from yellow fever and dengue fever hundreds of years ago but you can be prosecuted by allowing standing bodies of stagnant water to persist.
KATY: Yeah. And when I went to New Zealand a couple of years ago when we were passing through Polynesia there were outbreaks of Dengue fever. So that's when I, of course, my research brain was like, why is there an increase. And there is a large association and it's also that we are in the United States and I'm not sure about other countries in North America too, shipping our used tires that we don't use any longer abroad.
JEANNETTE: So ok, it's fine for other people to kill themselves with bald tires.
KATY: Well they're less expensive and also where are you going to put them. And then what happens is they hold standing water. So very quickly the ubiquitousness of the residue of the car-centric culture ends up affecting mosquito breeding grounds and then you end up increasing mosquito-borne illnesses. And it's not a very big step to tie it back to what are other symptoms of our lack of being about to carry our bodies great distances. And it's like, how do you put in a mosquito based disease? When you can see it so clearly from excessive standing water. But of course, you can see that with the understanding of the catalyst for sickle cells evolving into a group was also the decision to change or modify the environment largely. We're going to cut the forest down and we're going to grow things here. And that ends up changing and then of course changes who gets to survive there. And then you end up over time without realizing it, shaping populations. So I was talking about that at a permaculture retreat because it was blowing my mind. It's like I wouldn't have tied dengue fever to the car movement without just this understanding of they're really trying desperately to, as you said, educate people on how to store tires.
KATY: But it's also if we'd also just drive less and don't use as many tires and go to public transportation you don't have such a huge waste. Because who thought of tires as being mosquito nurseries. But they are. And they are in the environments where rainwater accumulates. And it's so easy to say, well just drill holes in it. But what if they go to areas where everyone doesn't have power tools in their own personal garage. Which is the other flip side of that. But yea, that bothered me a lot when I read that. But anyway, ok, so culture. Culture is definitely at play when it comes to our genetics although the scale is longer, for sure.
JEANNETTE: Right. Yeah.
KATY: Oh my gosh. Where to now? We could just keep going.
JEANNETTE: Yeah. I know. We could keep going.
KATY: So horns are not... I keep calling them horns...
JEANNETTE: Yeah, so there was no way that the horns or whatever else you want to call them are a genetic change. You need hundreds, thousands, of generations to really see...
KATY: And it would have to be a benefit. The person with ...
KATY: ... the person with the change would have to be more successful in a particular environment. But then I was thinking, well, I guess if the future is all tech-based with the person with the longer lever, you know, would the neck be able to withstand larger bouts of time. And that's to me that's the loop. We are really well suited for the chair. We are really really well suited for ...
KATY: ... well, we don't know what it is. And also, one of my other points is, handheld devices is such a random thing. I mean you are looking at - this is my other critique of the paper - which is, this is the first generation, they measured 20 to 30-year-olds, this is the group. Or 18 to 30-year-olds. It's not just handheld devices. This is the first generation that's grown up completely on a computer.
KATY: You know what I mean? I got my first home computer when I was probably 12. But it was such a small percentage of my life. I had two crap games. And most of them were just typing. And I never played them for more than an hour every couple of days because it was much more fun to go do other things. Everyone else was doing other things. So everyone else was drawing you into a bunch of other things. So it's really recently that children have spent so much time on the computer and also not doing anything else. Not walking, not riding their bikes, so it's not only this idea of things in our hands. I think there's a lot of interesting ways that this research can be continued upon. Because these are new skeletal environments. But will it persist? I don't think so.
JEANNETTE: Yeah. No. And the other thing is, and this is, again, maybe getting too complex. But when we go back to where this is what we would call phenotypic plasticity. Your skull is responding, this feature is a response to the environment. Now there's a lot of debate that goes both ways but if phenotypic plasticity could constrain evolution and it could potentially accelerate it. So by that I mean if you already have the flexibility to deal with a situation it may constrain evolution because there won't be significant advantage to the person who mutates a, something that's constitutive. By constitutive I mean they always express this external protuberance. Because your body already has the capacity to do it if it needs to.
JEANNETTE: So does that make sense?
KATY: I said no. So in my mind, I was building the example of, this is not something you're born with. Right? This is something that is increasing in length over time - over load applied over time.
KATY: But your plasticity, your ability - sorry I'm just trying to talk myself through so you can see where I don't understand.
KATY: So my ability, though, for it to grow longer, my plasticity, my phenotype plasticity, that's just what it is.
JEANNETTE: Exactly. I think I haven't explained myself well. So we have that, assume, we have that plasticity. I know nothing about the genetic control of these exostoses and it seems to be from just the few bits that I've looked at through these papers that it seems to be early on in development everything - the bones and the joints and - are set.
JEANNETTE: But what I'm saying is if you say just theoretically, that a mutation occurred in development - in a developmental process that meant that you had a larger protuberance at that point.
KATY: That you came with the gene for an adult you're going to have the ten millimeter...
JEANNETTE: Yep. Exactly. Which is unlikely because often development is quite constrained. But in theory, if you had that you would really have no, say there was a selected advantage. In theory, something made you made this impact your reproductive fitness or your survival which again is a longshot but let's just say that was possible or occurred. You still have nothing over the person that had the flexibility to generate it by phenotypic plasticity. So there's no differential between you for selection to act on. So that's why there's a theory that actually our flexibility or our ability to be phenotypically plastic can actually constrain genetic change for that reason.
KATY: Um-hmm. That's why we haven't changed that much. Because our plasticity range is quite large.
JEANNETTE: It's quite large. And yeah and lots of things like this are set by regulatory path gene pathways that are very unlikely to change because they're all interlinked and it gets very complex. But it's just - it seems the situation on so many levels that it would be unlikely that we would see any evolutionary change in that feature.
JEANNETTE: That was a very long way to say that.
KATY: No. I mean we've already talked so long, who cares now at this point. This is going to be the Joe Rogan 3-hour podcast that's what's going to happen now.
JEANNETTE: We're getting pretty close to the 2-hour mark now.
KATY: That's right. Well, it's, you know I always feel bad because I always want to lead in with these things are complicated. Because I don't want anyone to feel badly when they don't grasp them quickly. Not that they're complicated. It's that they require years of hours of investing time to work up to gathering the pieces. And that's what makes the ideas more accessible.
JEANNETTE: That's right.
KATY: Because of the time in years, in volume, that we've all dedicated to whatever the thing is. You know, some people can knit and I can't do that. And it's not that it's complex. It's so easy. And it's not easy. Because the hours that you've invested. So these things that we're talking about, I don't think are any more challenging to grasp. It's just that - what's a challenge is more, I would say, on my end or your end, to take something that we have understood in a particular way because of the years of hours of investment into a way to make them useful or relevant or helpful to you in a one hour show. That's what's challenging. But we're already at a two-hour show because that's what we had to do because of the years going into all of these things are a lot.
JEANNETTE: That's right. Yeah. And it's hard to be succinct when there are so many interlinked phenomena.
KATY: It's hard to be succinct when every single word has to be defined. That's all jargon is. Jargon is succinct terminology for those that chose to study the years to understand which each of those words mean. So, it's just that. So to go jargon-free - jargon exists because a lot of words represent concepts that take a lot of explanation. They take a lot of other words. Ok, you've got other words? The word we're gonna put on it is plasticity.
KATY: You know what I mean? But it took all these other words. So I don't think jargon is meant to be not inclusive. It's just we all chose where to put our time. But also we have to function - we have outsourced understanding to different things to different folks. And so this is a way of how do we get some of it back. Because maybe now we're willing to put in time to learn different things. And I appreciate your help in clarifying some of those terms. I think it'll make it, hopefully, a lot more clear for everyone.
JEANNETTE: Yeah. Hopefully. And I think lots of people are interested in genetics and evolution. And evolutionary medicine and the evolutionary mismatch theory. And I think there's a lot of general interest in that. So having a little bit of understanding of the words that might be used is hopefully going to be helpful.
KATY: Oh I'm sure I could have you on five more times. We'll just keep talking about things like this.
JEANNETTE: And just talk about stuff that we just talk about just to each other.
KATY: This could be so great.
KATY: Human being, social issues. So I have lots of different hats that I wear. So without saying it has to be a biological takeaway or a technical takeaway, what's your takeaway?
JEANNETTE: My takeaway, I think, would be I had some issues with how the paper was written but I don't believe these guys - I think they just made some mistakes in how they present things. Or maybe not presented it in the best way. But I would definitely look at this and think habits have consequences. And these guys are chiropractors that presumably seeing something quite interesting in their population. They might have something in it. So it would definitely be if it's true that we're seeing these things in younger and younger people, its something we should be aware of in terms of our habits. And I definitely, not just from this study, but from everything else that I have read think that extended periods of sedentary time, looking at a device has negative consequences. So, I think it's valid. I'd be really interested to see what comes out of it. But as a parent it's definitely - I do not want my children to spend hours in any position for any length of time really. But I also, as a parent, have that whole guilt concept of what do I do about it. And I think that's where your work comes in so well. But we have all the issues with schools, and screens and how to navigate that. Which is super challenging, I think for our generation and our kids.
JEANNETTE: So. Yeah. And that's the point when I put my head in my hands and I just want to sell my house and go buy a plot of land in the middle of nowhere and but yeah. I think that's my takeaway. It's worth taking these people seriously, I think.
JEANNETTE: And seeing what comes out. I think now there will be lots of follow up of this kind of thing and it will be interesting to see what comes out of it.
KATY: I think my takeaway is probably fairly similar. I can see some of the tendency to dismiss as "these have always ranged in shape and don't worry about it." And that is true. There's always - there are many documented ranges of shape. Of course, no one has correlated them to the weights of the heads. You know what I mean?
JEANNETTE: Right. Yeah.
KATY: It was very Move Your DNA as far as the orca fin goes. Male orcas have taller dorsal fins.
KATY: They have bigger bodies overall. So my hypothesis would be that you see longer protuberances in heavier heads and probably males tend to have heavier heads. But you would see that there was a natural relationship between length and weight. Because that's what it's for. And also I think it's really important that none of the papers discuss that your trapezius muscles. It's not just the weight of your head, it's also the tension. So that's another piece and why ...their measures of posture were poor. And I also don't think that posture is the best thing here. I think load is the bigger thing to understand. Also, two-dimensional posture measures scientifically are very poor because of the way that it's done. But anyway, if we were to do something more about measuring trapezius EMG for example, that would give us greater understanding of just the amount, just the tensions that are on this bone. It's not only the weight of the head it's all these other things. But you could do little things like bend your knees to make the weight of your head less. So there's a lot of compensation things. But anyway, that's mechanical aside. The other thing that would be concerning is that these are normal. Variance is normal. But it's kind of like a folded fin. There's a difference between seeing a few orcas with a little bend to their fin from a known accident or a known outlier and then seeing every single one who lives in a particular way with a folded fin. So you can put them under the sentence of going folded fin syndrome. We see it in the wild. We see it here. Ok, that's true. But what is the frequency and the distribution and the actual geometry? So that's what they're doing here so I pay attention to that.
JEANNETTE: Yeah. I think it would be really nice if they started to compare this data and other data sets for X-rays to fossil remains. And there's lots of collections of skulls which are presumably much easier actually to measure.
KATY: Actually measure.
JEANNETTE: And also they have populations which had very high load to the area. Like what's the term? Tumpline? Tumpline. Where they have the men and women that carried things with a band around the forehead and then they carry them and there's a baby on the back. And I think those populations are very high load to the head and the neck where they're really using the neck and the back to help support the weight. I think that's where you see this as well. So it would be very interesting to see well we know that these populations have this very high load and then we compare to other populations who are weavers or I'm thinking of victorian Britain where they had people working at looms and for very long periods of time, whether those people also had these kinds of issues. To try and build up a bigger picture.
KATY: A bigger mechanical ...
JEANNETTE: A bigger mechanical picture. And I hope that this paper might actually bring those two fields together. People actually do some really big big studies.
KATY: There's so much out there. Some graduate study sees and hopefully... "that's my thesis right there."
KATY: But I also think that seeing something in children that you've only seen in adults is also an issue because you're setting bone - bone robusticity and bone density are interesting. I don't know if this would fall under plasticity. You kind of set limits when you're a child for your skeletal experience as an adult.
JEANNETTE: Right. Yeah.
KATY: And so and the people who do have larger protuberances, there's surgery for it. It is not symptom-free. So that was another thing that was expressed. It's like we're seeing this thing that has known - whatever a shape - so what. Well, there's symptoms and surgeries associated with this shape and the fact that it's becoming more ubiquitous perhaps and at a younger age this would be predicting the experience for a group of people and then trying to figure out why. And I also think that with technology, whether this is technology. I mean weaving was technology at some point. And people figured it out and we've been trying to get away from it.
KATY: I'm very hopeful. When I think of smoking - if I look at TV movies from the 50s and the 40s and photos, everyone was smoking. They were smoking on TV. Doctors were smoking.
JEANNETTE: Oh yeah.
KATY: There were no good use practices around it. And technology has come on so quickly there are no good use practices around it. And I think that we're pretty good at recognizing an issue and then trying to put safety practices around it. Right? We've done it with... I've had this dream of doing this video, you know, just about the addictive nature of let's just say handheld. If you think of every time you picked up your phone. It's on the toilet. It's in your car. It's all these sites. Imagine if you just had a flask and were taking a nip out of your flask.
JEANNETTE: Oh yeah, that's true!
KATY: And taking a video of just like, drinking it. This would be a problem if it was alcohol. If you were taking little sips of it while you're sitting at a stoplight because you couldn't go for a full 11 minutes without checking...
JEANNETTE: I can't tell you how much I love that picture on so many levels.
KATY: Can you imagine a little video of "this would be a problem" and then just do it with the phone to get some context for what it looks like. And that's another thing. I don't think that technology requires a head position. That's the other assumption here.
KATY: This is the other takeaway for Move Your DNA. Part of what we're trying to do is how do you participate - how do you not miss the note from your office but don't have to get a horn about it. You know what I mean?
KATE: The horn is a load. The cell phone is not triggering a bone growth. They're talking really about this idea that how you use your body affects its morphology or its phenotype.
JEANNETTE: Yep. Wonderful.
KATY: Thank you. I try to incorporate people's words right away. Ok, I hope this has been illuminating. Jeannette thank you so much for coming on. We could talk forever.
JEANNETTE: Thank you for having me. It's nice to have someone that appreciates me rabbiting on.
KATY: I do. And I think a lot of people would like to know more. It's so very helpful. To read more about and by Dr. Jeannette Loram, or take a Move Your DNA Weekend with her, or another of her workshops, visit her website www.jeannetteloram.com. That's 2 n's and 2 t's. J-e-a-n-n-e-t-t-e Loram L-o-r-a-m dot com. You can also find it linked in the show notes. Thanks for coming on.
One, I am heading back to Cambridge, UK, August 31 for a one-day human movement on and off the mat workshop and I’d love to see you there!
Also, regenerative rancher and author Doniga Markegard who was on the show last year, she and I are once again joining forces. We’ll be in Ojai California on Sunday, September 22 for another edition of Wilderness Moves. This event is focused on the movements that relate to growing and gathering food. It’s gonna be a good one. Come if you can!
You can find details about both of these events at nutritiousmovement.com. Go to our live events page. And while you’re there, sign up for my newsletter. My social media break continues, and so does my newsletter. It’s the best way to find out what’s up, yo. Also speaking of the social media break, one of the things I will be doing this summer while not on social is working on a new book I am very excited about. It’s a book about kids, family movement, and movement ecology. I’d love to include your stories about how you move with your kids, how your kids move with and without you, how you’ve changed habits and habitats to get more movement and nature into your family’s or maybe your classroom's life. Everyone’s stories matter tremendously; the more diverse a range of stories, the more folks this book can speak to. If you would like to share your story and circumstances, your solutions with me, urban, rural, everything in between. We want international submissions and submissions from those with (or those who have kids with) disabilities. There’s no particular story I’m after. Transitioning to more movement, more nature, and more natural movement is a lifelong journey of small steps. And often small steps are the most attainable for others just starting out. So if you’ve found any step, big or small, that helped you create magic and movement for your family, I’d love to include it in Grow Wild You can also find the submission guidelines in the show notes for this podcast. If I use your story, you will receive three signed copies of Grow Wild when it comes out!
That's it for Move Your DNA this time. Thanks for listening. Until we meet again, remember to go deeper into your movement rich life and into the story behind the story. Peace!
This has been Move Your DNA with Katy Bowman, a podcast about movement. Hopefully, you find the general information in this podcast informative and helpful. But it is not intended to replace medical advice and should not be used as such.