Ongoing Evolution

Nicholas Wade of the Times follows up on the story from Tuesday about the ongoing evolution of the human species:

The Twists and Turns of History, and of DNA

EAST ASIAN and European cultures have long been very different, Richard E. Nisbett argued in his recent book "The Geography of Thought." East Asians tend to be more interdependent than the individualists of the West, which he attributed to the social constraints and central control handed down as part of the rice-farming techniques Asians have practiced for thousands of years.

A separate explanation for such long-lasting character traits may be emerging from the human genome. Humans have continued to evolve throughout prehistory and perhaps to the present day, according to a new analysis of the genome reported last week by Jonathan Pritchard, a population geneticist at the University of Chicago. So human nature may have evolved as well.

If so, scientists and historians say, a fresh look at history may be in order. Evolutionary changes in the genome could help explain cultural traits that last over many generations as societies adapted to different local pressures.

Trying to explain cultural traits is, of course, a sensitive issue. The descriptions of national character common in the works of 19th-century historians were based on little more than prejudice. Together with unfounded notions of racial superiority they lent support to disastrous policies.

But like phrenology, a wrong idea that held a basic truth (the brain's functions are indeed localized), the concept of national character could turn out to be not entirely baseless, at least when applied to societies shaped by specific evolutionary pressures.

In a study of East Asians, Europeans and Africans, Dr. Pritchard and his colleagues found 700 regions of the genome where genes appear to have been reshaped by natural selection in recent times. In East Asians, the average date of these selection events is 6,600 years ago.

 

Comments

[boris]

There's a saying that speaking Chinese runs in families but is not genetic. However, it seems plausible to me that children of Chinese descent might have an advantage learning to speak, read and write the language. Genes present in all human populations that favored certain vocalizations, drawing and interpreting the pictograms used in the language would in Chinese culture bestow social advantage. Such advantage could apply to mate selection and providing for family and offspring. Over time the genes might become more prevalent in that region relative to areas where they provide no significant advantage.

Just a thought.

[ajacksonian]

Or these could be traits limited to the original settlers in dispersed geographic areas passing such on to descendents and they are not being changed as there is no selection pressure against them. That Founder Effect has to be taken into consideration along with dispersion of the original traits within the limits of the original gene pool.

Hard to tell if something was being selected *for* via environment or just not enough time for mutations to slowly disperse into a limited suite of genes from the founders.

It may just be a trait that gives some plasticity in certain areas that, on the whole, are neither positive nor negative and without original diversity just get passed on. A proper study would do a diverse look over an entire region of all extant populations that have no direct tracing through other lineages and see if this is the case. Then compare that with similar nearby populations and some sort of control group (say some part of central asia that has seen a wide diversity of peoples over time, like Alexander the Great's conquest route). If you see similar effects in other somewhat isolated genetic populations you *may* have a selection factor at work, but then would need to be examined for exactly *what* that factor could be.

Over the last 6,000 years climate has altered drastically on a global scale after the end of the last glacial period and the full restarting of multi-ocean basin currents. The area of Iraq and Iran went from wet, fertile grasslands to low rainfall areas and desert, as an example, and I believe Central Asia has seen similar shifts. So any shifting in genetics would have to rule out changes to diet due to climactic change...

Genetics... very fun to make a supposition, but so many factors to take into account... very, very difficult to tease out subtle effects of changing civilization against larger effects of climate change and migration.

Which, of course, bores the hell out of everyone.

[dave]

I thought Wade was being irresponsible in writing this article and pushing this sort of speculation. I don't think any of these studies show any convincing link between genetics and the suggested behavior, it is something like propaganda in my opinion.

[TM]

I thought Wade was being irresponsible in writing this article...

I had said in my earlier post that we are getting close to my personal "Say no more" point. Much as I hate to sound PC, this stuff could easily be inflammatory, oversimplified, etc.

[ajacksonian]

About the only thing that can be said about the broad genetic analysis is... all the variaties of human are one species.

One can give some fine speculation that the original large grouping from Africa was a pretty shallow source without a huge amount of variation. That fits.

One can reasonably guess that the crossing happened at something close to a large clan/village level sizing by group, and looking at primitive people village sizings that each set would be a maximum of 120-150 people due to social interaction pressures. Not a *bad* fit with human variation distribution.

By looking at the fossils (of which much of the coastal ones are underwater due to variations with glaciation) a few main pathways out of Africa were used and pretty well traveled. Due to limitations in viability of genetic material, you are stuck with forensic bone analysis and trying to fit them into basic population variations and climate, food sources, activity, etc. Not bad for the sparseness, but I wouldn't want to stake a good meal on it, either.

What one *can* say is that the structural difference between Neanderthalis and Sapiens points to extremely different climates. Neanderthals were tough folks! Much higher bone thickness and density, shorter, squatter, and pretty resistant to pain. Thicker hair over the body, from what we can tell of remains. These trends in animals point to colder climate to fit a better body mass to surface area ratio for lower heat loss. Sapiens are typically 'gracile', with long limbs, lower body mass and higher center of gravity. This trend is typically that of grasslands to desert, maximizing surface area for cooling. If we had a higher proportion of body fat then you could point to a semi-aquatic environment, but the overall height and lower mass are not good for heat retention in water. Go from air to water, both at the same temp, but just below body temp and see which cools you off faster.

Without *lots* of brain casts from fossils, trying to purport genetics driving internal brain organization or more ephemeral mental characterstics is, basically, a guess. Down at the cup of coffee range, for me, and heading to into the penny tootsie roll area.

Linguistic analysis might be a good indicator, but trying to see linguistic shift and having to account for interaction with neighboring languages is extremely difficult.

Much better would be a Y-chromosome analysis to link population types backwards. This has done a lot for recent lineages, such as Genghis Khan and Alexander the Great, so some genotyping and cross-matching should help there.

From what I remember of mitochondrial DNA, and it has been awhile, there were some indications that it was only a high percentage maternal lineage passing, and that some smaller percent actually did get paternal mitochondria. Haven't checked that in a few years, however. Still, a good sized statistical analysis would help and eliminate some outliers. Cross that with a Y-chromosome analysis and population spread and trends start to look not too bad.

Now you could be up to the cup of coffee range again... and stuck with ecology, shifting weather patterns and their attendant caloric budgets. And as the glacial period ended, populations would be pushed slowly together as the continental shelves went under water.

So much to consider... and you don't even have to go into the Island phenomena! Although for actual islands.... hmmmm.... still doesn't seem like enough time for that to have happened in either direction...

Which all puts you back at the Founders of the lineages in question and the ecological changes. And no selective factor *for* these things... and human mating patterns do factor in, but then the morphotype vs genotype (or is it phenotype vs genotype?) problem arises as different genetic suites can get similar morphotypes (must be morphotype).

Can we get back to this question either when: a) a time machine is invented, or b) about 10,000 years or so of selective factors are thoroughly tested for?

[boris]

I thought Wade was being irresponsible in writing this article...

I had said in my earlier post that we are getting close to my personal "Say no more" point.

What amuses me about the subject is how many in the anti-ID pro-evolution group start having vapors when these subjects come up.

Geographic human populations whose long term environment involves a stable culture will likely develop cognitive adaptations to it. But suggest that differences between groups are in any way inherent and see how quickly many supposedly pro-evolutionists go ape.

[boris]

One method for trying to return a once good sport fishing lake after junk species infestation is to kill off all the fish in the lake and repopulate with sport fish eggs from elsewhere. One reason it doesn't always work very well is that the replanted fish don't have the natural selection adaptations to that particular environment developed over geologic time.

These aren't necessarily mutations. They're just inherited traits attuned to unique attributes of that lake.

Boys may grow up and marry girls similar to their mother not because they want a girl just like mom but because they inherit their dad's taste in women. Calling that a "genetic" trait is misleading. There's no gene for that. It's those kind of inherited inclinations that allow a gene pool to adapt to changes in environment or location without having to wait for a lucky cosmic ray.

[SteveMG]

TM
I had said in my earlier post that we are getting close to my personal "Say no more" point.

Could you flesh that out a bit? Misuse of science has a long history, to be sure, but it seems to me that the study of genetic/cultural co-evolution (to oversimplify it perhaps) in man isn't any more (potentially) dangerous than the study of evolution itself.

Seems to me that any danger here - biological determinism - will only come from those who are collectivists and who treat people as a member of a group and not as individuals. We all know which entity tends to embrace that view. And they most emphatically reject this type of study (as Edward O. Wilson will testify).

Greater danger in stifling this research (not that I'm accusing you of that) than in engaging in it.

SMG

[dave]

I think we probably agree TM.

My point is that there are the genetic results which are most likely very sound, and the purported behavior which really is not connected to the observed mutations.

The "propaganda" is the supposed effect on language or calculating ability, for which there is no evidence other than the bias of the research head.

[TM]

Could you flesh that out a bit? Misuse of science has a long history, to be sure, but it seems to me that the study of genetic/cultural co-evolution (to oversimplify it perhaps) in man isn't any more (potentially) dangerous than the study of evolution itself.

Well, I am firmly straddling this one - in Oct 2004 I pointed out the absurdity of what I will call the PC Lib position, based on a NY Times magazine article - stem cell research should go full speed ahead, but research that suggests that race based differences have a basis in thehuman genome are a no-no.

However, last Tuesday the Times told us that:

...Dr. Pritchard also detected selection at work in brain genes, including a group known as microcephaly genes because, when disrupted, they cause people to be born with unusually small brains.

Dr. Bruce Lahn, also of the University of Chicago, theorizes that successive changes in the microcephaly genes may have enabled the brain to enlarge in primate evolution, a process that may have continued in the recent human past.

Last September, Dr. Lahn reported that one microcephaly gene had recently changed in Europeans and another in Europeans and Asians. He predicted that other brain genes would be found to have changed in other populations.

Different brain sizes amongst Asians, Euros, and Africans? That would be a tough one to discuss sensibly.

And yes, individual variation swamps group variation. Still.

[willem]

Still it strikes me as a rather dangerous form of phrenological revisionism. The political focus is to tie skin color and particular "phrenological" features to geographical regions in a framework that rehabilitates the mythology of 20th Century racialism. Aneuploidy predicts that nutritional, toxemic and disease pressures drive genetic changes. Within evolutionary time frames, the geographicality of genetic variation/specialization is very much a product of aneuplody, and the nutritional, toxomolecular and other endogenous/exogenous stressors in play. Variations in human skin tone and facial features are not "genetic" as in the paridigm of racialism that was sold to the public during the last Century. It has been this version of racialism that was skewered by the emerging science of genetics over the last several decades, as there were no specific "genetic markers" for the variations in physical appearance called "race." What we are seeing here is the overt manipulation of science to perpetuate an obsolete political model of race. One will find genetic markers consistent for geographic populations in Ghana or Eqypt, or Denmark, or Russia, Italy, Spain, China or Mongolia, but these are not markers for blackness, whiteness, yellowness, laziness, hardworkingness, gangsterness, muslimness or other vapid racialisms that have been exploited duplicitiously by racial racketeers of all persuasions. Keep your eye on this one. The fraud is unfolding before your eyes. I thought the draconian notion of "race" would finally die the death it had long deserved at the hand of the genetic sciences. I should have realized that anything can be coopted and rehabilitated -- even Hitler's one drop rule. In today's multiracial America and melting pot world, how many drops of of black blood make you black, and how many drops of white blood make you white? How many drops make you Jew? Muslim? How many drops until you "pure?"

This ain't science. It's Mengele meets Mugabe.

The exterior surface of the human body represents far less than .000001% of the total interfacial cellular surface areas of which our bodies are comprised. That is how ridiculous the 20th Century notion of racialism is. Individual genetic variation dwarfs by magnitudes the victorian notion of racial difference.

[Harry Arthur]

boris, see how quickly many supposedly pro-evolutionists go ape.

Interesting choice of words while on the topic of evolution, don't you think?

[Harry Arthur]

willem, why would the topic surprise you, given Darwin's racism?

[Lew Clark]

It would be much better study if they could determine why liberals have really small brains and conservatives have large brains. Especially if they could determine if it is genetic or if the thought processes of the two groups cause the brain to shrink in the former and grow in the latter.

[clarice]

Lew!

There are so many things that go into how we think .I've always wondered if people who use pictographs like the Chinese and Japanese are so good at architecture and spatial relations because they focus on those things in learning to read and write.

[Rick Ballard]

Lew,

I thought it was pretty well established that the cause was a misalignment of axons and dendrites - only the left half actually makes a connection. Maybe that would cause atrophy though, so you may have a point.

[cathyf]

I'm wondering how much of this is plain old-fashioned innumaracy. Like, man, 6 thousand years is a long time; 6 million years is a long time. The human transition from carnivore to omnivore is about 10,000 years old, and we are clearly not evolved for our omnivorous life yet. With cultivation of grain for food and water purification (bread and beer) comes tooth decay, degradation of women and children, obesity and diabetes, war, heart disease, poverty, etc. If we evolved as fast as 6000 years, we'd look a whole lot different by now.

(Of course I have to point out the irony of the radical vegan crowd, who are almost always viciously dangerous utopians. The utopia that they claim will occur when we all go "back" to eating strictly vegan diets only existed back in the days before we invented agriculture when the human diet was 90% meat.)

The other part which makes the analysis suspect is that humans are intelligent and resourceful and clever, and are very good and figuring out way to prosper in environments which are not necessarily a perfect match. Given that we adapt to our environments by designing and building tools, we don't have to wait for the progress of evolution to give us what we need over slow millenia; we get it right away by being clever. We need to go fast? We could evolve the legs of cheetahs over hundreds of millions of years. Or we could figure out how to domesticate horses, and invent cars and trains and airplanes and spacecraft -- that just took a half million years to get from the emergence of homo sapiens as a species to us flying to the moon.

cathy :-)

[larwyn]

wILLEM wrote;
"Aneuploidy predicts that nutritional, toxemic and disease pressures drive genetic changes."

And Lew joked about the differences in brain size RIGHT vs LEFT.

What about the toxic effects of drug use? Current use and use passed on by immediate ancestors.

It is a bit the discussion on this thread re what the PC crowd will allow - but on one hand they admit the damage in "crack babies" and then we see no studies at all on genetic damage being passed.

Only people I am aquainted with that admit and think it is fine to use "recreational" drugs are far lefties with pronounced BDS.

Are there studies and if not, why not?

[Neo]

I suggest they embrace the notion of "un-natural selection".

Un-natural selection is that selection which is imposed by tyrants and slave masters who desire submission and productivity, while eliminating rogue elements that disrupt their societies.

In the world of "kumbaya" academia, ruthlessness seems to be reserved for the most recent centuries. For some this brings to mind Stalin's purges, Mao's "Great Leap Forward" and the "Killing Fields" of Cambodia and Rwanda (but if you ask I bet most academics only remember Rwanda, maybe Cambodia).

My point, is it really evolution if it is done by "un-natural" selection or is it (deviant) intelligent design ?

[ajacksonian]

TM - Still?

Founder Effect - For a varietal racial group this will have enormous impact on variation. Also note that Amerinds are descendents of the Asian population, so we should see many of the same variations in that sub-group. However, their differences in diet and climate changed their caloric budget so that they varied in their morphological characteristics. Their retention of certain genetic traits that are non-survival determinative that are in common with their Asiatic Founder Population (such as the common inability to metabalize alcohol as seen in sub-populations in Japan, Korea and China, but not elsewhere) demonstrates that climate change and caloric intake will have an overwhelming effect on general growth characteristics.

Has an Amerind study been done to demonstrate brain size, structure and changes due to this as variant to their Ancestral populations in northern Asia and Siberia? They will, of course, show some climactic sieving due to that more northernly climate base for their Ancestral start, so a cross-comparison would offer unique insights into how human physiology changes with limitations in caloric intake and weather patterns. From there the re-expansion of populations into more temperate North and South America will show sub-population Founder Effects for various groupings across the Americas.

Has that been done?

Cherry picking evidence to demonstrate a single thing is easy. Demonstrating how that evidence fits into the entirety of the body of evidence and continuing to demonstrate that the cherry picked data still has causational meaning when measured against other groups undergoing similar changes is difficult.

The concept of adaptation via aptation of previously existing characterstics is pretty well understood. A body feature that had neither positive nor negative impact upon survival and differential procreation would tend to be a non-harmful allele in the overall population. Demonstrating that something is now causing that aptation to have adaptational significance is an extremely difficult proposition, especially if the causal link is indirect. Culture gets to be pretty high up on the indirection chain, which is swayed heavily by migration, climate and sub-group changes *before* culture even has a say in things.

Of course this is only where things stand at the start of the 21st century taking population mechanics, genetics, population effects of many sorts, understandings of geographical and climate islanding, morphology and a whole host of other interlocking material that has had to have been incorporated into Evolutionary theory since Darwin. And this continues to change as we better understand what causes genetic changes and how some ancient parts of genetic code are used differently amongst different species.

An example of this is a retroviral gene suite that got incorporated into the genetic code quite some time ago, but was most likely common to the therapsids. It changed and drifted from its original coding, as it was rendered non-functional for some things, although may have actually been incorporated into the overall immune system to make it more capable against some viruses. Mammals suffered a mutation that caused it to allow one major change in the reproduction cycle: continued feeding via placenta and then sudden expulsion as the gene kicked out of use and the child was expelled as foreign genetic material. Live birth. We only know this by studying AIDS and other retroviruses and comparing them to the human genome. And there, within our genetic structure, sits the remnants of a retrovirus. This remnant has seen high maintenance in all mammals and is a genetically defining part of mammals that give any form of live birth via placental nourishment. It is now essential to survival and variation in it tend to cause reproductive problems and death, and so such changes are not passed on.

Or so I was taught. A *real* geneticist could probably give you all the details, not my limited thumbnail mangling that I am limited to these days with poor memory and comprehension.

So, I will wait for either: 1) a time machine, or, 2) 10,000 years of good solid evidence to be uncovered or found through normal reproductive processes.

[boris]

If there was a point in there I missed it.

[Neo]

ajacksonian:

I think this means that you don't believe it has been proved.

Blink twice if you agree.

[ajacksonian]

Neo - Not enough data points to tell.

Much hand waving, much hot air and supposition.

When the hand held genomic readout device is put together in 10 years or so *then* we will start having fun with genetics and population variation and be able to properly see how the affects of climate and caloric intake change morphology.

Structural and other changes are in a multivariate space. Not enough accounting for the variables along the axes... just trying to point out that the axes are themselves somewhat complex, although the rules governing them are not. Need *lots* of data so we can figure out how to subtract the larger magnitude changes and see if there is anything left from those. Working the other way around can give you misleading results due to not properly understanding the large order of magnitude changes and how *they* operate.

Talking about spark plugs and gap width and such is all very nice, but if there is no gas in the tank, the car is not going anywhere... and heaven forbid you lost your *keys* someplace. Have to account for the large order stuff *first* and THEN figure out if the plugs you have been working on might actually do something... and if your car is diesel, then you are stuck with something you spent a lot of time on, but...

Until then, color me in the 'uh-huh, nice data points you got there, hate to have 6 billion people happen to it' group.

[boris]

Ah, I see, so it's impossible to study genetics without an electron microscope and a DNA map. Good thing nobody told Mendel.

Either evolution works or it doesn't. Populations adapt to their culture if it does and science always beats PC mumbo jumbo.