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Forearm artery reveals human evolution continues?

news.flinders.edu.au

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Re: Forearm artery reveals human evolution continues?

#51

Post by bonoboTP »

danieltillett wrote: post #49
tyre wrote: post #47

Earlier quoted context omitted.

With a limited pool of funding, how would you decide? If a committee, how would they be chosen, guarding against bias, etc.

This problem has been solved long ago. Screen all grant applications to weed out the flawed approaches (the bottom 25%) and then run a lottery on the remaining. If there is nothing to game, the gaming stops.

But it goes way deeper than just grants. Who will get tenure for example? Citations and publication counts are used for many many things. Also, making your findings sexy is not just done to improve metrics for promotion and grants. Sexy research also draws attention among experts and lay media alike. They will be invited to give talks at conferences and seminars etc. more if their findings are exciting.

Re: Forearm artery reveals human evolution continues?

#52

Post by ffhhj »

Ericson2314 wrote: post #16

> Humans haven’t developed mutations or superpowers just yet, but a new study shows our species is still evolving in unique ways and changes in natural selection could be the major reason. Ewwww. Why is university press the worst? If we are still evolving and this isn't just about genetic recombination then by definition mutations are involved. Also the publicist writes > This evolutionary trend will continue in thos…

"Evolutionary intertia"? Evolution is change, and inertia is the resistance to change... it makes no sense anyway.

Re: Forearm artery reveals human evolution continues?

#53

Post by bonoboTP »

sradman wrote: post #42
mci wrote: post #28

I have procured a PDF of the paper. Ctrl+F race finds nothing in it. The authors treat e.g. these results equivalently: * Adachi, B. (1928) Das Arteriensystem der Japaner. Kyoto, Japan (8.00%) * Kodama, K. (2000) Arteries of the upper limb. Tokyo, Japan (8.2%) * Henneberg, M. and George, B.J. (1992a) High incidence of the median artery of the forearm in a sample of recent South African cadavers (27.10%) * Cheruiyot,…

> The focus of this study was not to analyse the prevalence of the occurrence of the median artery in relation to ethnicity, geographic origin or variations by sex, but to identify the global trends in its occurrence. Hopefully this paper will inspire more research involving this interesting phenotype. I'm curious about the population specific prevalence too.

Do I understand correctly that their observations are compatible with the possibility that some ethnic groups have more of this phenotype and these ethnic groups are becoming a larger percentage of the world population in general? This would make the story about the artery a red herring.

For example if Northern Europeans started reproducing at a higher rate, could we say that humanity is evolving more and more lactose tolerance? I would say that would be very misleading.

My question is, does their methodology tell apart the following effects:

- The new artery is spreading across the board in various places, e.g. there is a general environmental selection pressure for random mutations in this direction, OR

- Populations that have it or don't have it are reproducing at different rates, possibly for totally unrelated reasons like socioeconomic ones.

Re: Forearm artery reveals human evolution continues?

#54

Post by lopmotr »

eecc wrote: post #17
carbocation wrote: post #10

The selection pressure on three versus two arteries feeding the hand has to be so incredibly small (in terms of survival to reproduction in humans) that I am having a hard time imagining how this story has any causal plausibility. Edit to be more clear about what in the article I'm responding to, it's this: > Dr Teghan Lucas from Flinders University says ... “This increase could have resulted from mutations of genes…

Well, Natural Selection doesn’t necessarily mean that only advantageous genes survive the Darwinian hustle, it can also mean that in the absence of negative external pressure also neutral variations are not systematically culled. It’s like living in a civilized society; you don’t have to worry of starving tomorrow so you take on making art...

It seems like we're on a terrible path with this absence of evolutionary pressure. What's happening to all the babies who survive today that would have died in childbirth had they been born at any time in human history before 100 years ago? Since infant mortality was so high, it must have been an close battle for evolution to keep it under control. Now the brakes are off and whatever mutations were regularly killing babies (and mothers) are now free to propagate to subsequent generations.

Not that that's necessarily a bad thing. We've already evolved to become dependent on technology (cooking, clothing, shelter) and it probably does us good by freeing up our body's resources to do other things better. So perhaps becoming dependent on healthcare for childbirth will eventually happen too and nobody will be worried when women can only give birth by C-section or whatever.

A related issue is immunization. People are so worked up about the politics that they don't want to think about this, but could it be that immunizing ourselves is taking away the evolutionary pressure to maintain a good natural immune system? Multiple generations of measles vaccinated people might end up like the native Americans who were vulnerable from their ancestors having never experienced measles.

This seems like a whole alternative kind of morality - protection of the genes of future generations. But it goes against the popular short term moralities that people have so it seems too objectionable.

Re: Forearm artery reveals human evolution continues?

#55

Post by mci »

bonoboTP wrote: post #53
sradman wrote: post #42

Earlier quoted context omitted.

> The focus of this study was not to analyse the prevalence of the occurrence of the median artery in relation to ethnicity, geographic origin or variations by sex, but to identify the global trends in its occurrence. Hopefully this paper will inspire more research involving this interesting phenotype. I'm curious about the population specific prevalence too.

Do I understand correctly that their observations are compatible with the possibility that some ethnic groups have more of this phenotype and these ethnic groups are becoming a larger percentage of the world population in general? This would make the story about the artery a red herring. For example if Northern Europeans started reproducing at a higher rate, could we say that humanity is evolving more and more lactos…

> My question is, does their methodology tell apart the following effects: [...]

First and foremost, their curve fitting, disguised as race-agnostic methodology, ignores the number of studies of the median artery in Africa 100 years ago (zero) and now (many).

Re: Forearm artery reveals human evolution continues?

#56

Post by x86_64Ubuntu »

mci wrote: post #28

I have procured a PDF of the paper. Ctrl+F race finds nothing in it. The authors treat e.g. these results equivalently: * Adachi, B. (1928) Das Arteriensystem der Japaner. Kyoto, Japan (8.00%) * Kodama, K. (2000) Arteries of the upper limb. Tokyo, Japan (8.2%) * Henneberg, M. and George, B.J. (1992a) High incidence of the median artery of the forearm in a sample of recent South African cadavers (27.10%) * Cheruiyot,…

I'm confused about why you would CTRL+F "race".

Re: Forearm artery reveals human evolution continues?

#57

Post by fs_tab »

x86_64Ubuntu wrote: post #56
mci wrote: post #28

I have procured a PDF of the paper. Ctrl+F race finds nothing in it. The authors treat e.g. these results equivalently: * Adachi, B. (1928) Das Arteriensystem der Japaner. Kyoto, Japan (8.00%) * Kodama, K. (2000) Arteries of the upper limb. Tokyo, Japan (8.2%) * Henneberg, M. and George, B.J. (1992a) High incidence of the median artery of the forearm in a sample of recent South African cadavers (27.10%) * Cheruiyot,…

I'm confused about why you would CTRL+F "race".

You would want to stratify results by race or ancestry, since this allele is probably more prevalent in specific populations.

Re: Forearm artery reveals human evolution continues?

#58

Post by fs_tab »

lopmotr wrote: post #54
eecc wrote: post #17

Earlier quoted context omitted.

Well, Natural Selection doesn’t necessarily mean that only advantageous genes survive the Darwinian hustle, it can also mean that in the absence of negative external pressure also neutral variations are not systematically culled. It’s like living in a civilized society; you don’t have to worry of starving tomorrow so you take on making art...

It seems like we're on a terrible path with this absence of evolutionary pressure. What's happening to all the babies who survive today that would have died in childbirth had they been born at any time in human history before 100 years ago? Since infant mortality was so high, it must have been an close battle for evolution to keep it under control. Now the brakes are off and whatever mutations were regularly killing…

Those are valid points. However, immunization has virtually eradicated entire families of diseases with serious, life-altering side effects. I would argue that the short-term benefits outweigh the potential long-term consequences in this case, especially if we continue to vaccinate children against these diseases.

That being said, I think it's far more likely that genetic conditions and predispositions to disease will be resolved through genetic engineering, not natural selection.

Re: Forearm artery reveals human evolution continues?

#59

Post by bewaretheirs »

sradman wrote: post #44
tgbugs wrote: post #41

Earlier quoted context omitted.

I work with a consortium that is trying to map the anatomy of the peripheral nervous system. My key take home has been that our knowledge of peripheral anatomy at population scale is woefully inadequate. People look at Vesalius and think "oh, that was settled 500 years ago," but as it turns out it seems that we know far more about the peripheral anatomy of our pets and domestic animals than we do about our own.

Is there a non-intrusive (and hopefully inexpensive) imaging technique that can be used on a living population rather than depending on cadaver dissection? Doppler, ultrasound, or even modified consumer wrist reflective PPG (like in the Apple Watch) should be able to detect the median artery. I imagine nerves are harder to map.

Doppler ultrasound can be used to measure blood flow; I've seen it used in prenatal scans to check for heart defects. I'd think it would be straightforward to use it to locate arteries in the forearm.

Re: Forearm artery reveals human evolution continues?

#60

Post by sokoloff »

danieltillett wrote: post #49
tyre wrote: post #47

Earlier quoted context omitted.

With a limited pool of funding, how would you decide? If a committee, how would they be chosen, guarding against bias, etc.

This problem has been solved long ago. Screen all grant applications to weed out the flawed approaches (the bottom 25%) and then run a lottery on the remaining. If there is nothing to game, the gaming stops.

Why wouldn’t the gaming morph to stuffing the lottery? Submit similar grants with different PIs, different combinations of researchers, slightly different focuses or plans.
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