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The Cultural Revolution in Genes
Scientific American has a remarkably interesting article about what a team of researchers have found through analyzing human genetic variation about the speed of our evolution. As SciAm reports:
Homo sapiens sapiens has spread across the globe and increased vastly in numbers over the past 50,000 years or so—from an estimated five million in 9000 B.C. to roughly 6.5 billion today. More people means more opportunity for mutations to creep into the basic human genome and new research confirms that in the past 10,000 years a host of changes to everything from digestion to bones has been taking place.
"We found very many human genes undergoing selection," says anthropologist Gregory Cochran of the University of Utah, a member of the team that analyzed the 3.9 million genes showing the most variation. "Most are very recent, so much so that the rate of human evolution over the past few thousand years is far greater than it has been over the past few million years."
"We believe that this can be explained by an increase in the strength of selection as people became agriculturalists—a major ecological change—and a vast increase in the number of favorable mutations as agriculture led to increased population size," he adds.
One quick note, the researchers did not analyze 3.9 million genes, but 3.9 million of the individual differences in genes called single nucleotide polymorphisms (SNPs). My favorite finding is:
"Ten thousand years ago, no one on planet Earth had blue eyes," Hawks notes, because that gene—OCA2—had not yet developed.
The University of Wisconsin press release adds some interesting observations from UW anthropologist John Hawks. To wit:
The findings may lead to a very broad rethinking of human evolution, Hawks says, especially in the view that modern culture has essentially relaxed the need for physical genetic changes in humans to improve survival. Adds Hawks: "We are more different genetically from people living 5,000 years ago than they were different from Neanderthals."
Humans alive today are as different from people living 5,000 years ago as they were from Neanderthals?! Fascinating.
SciAm article here and UW press release here.
Disclosure: My eyes are brown, but some of my best friends are blue-eyed and some others have green eyes.
|12.12.07 @ 10:05PM|#
It's reasonable to assume that the pace of human evolution has been accelerating in First World countries at an increasing rate lately as people rapidly (by geological standards) adapt to technological advances -- birth control, a plentitude of food, cars, computers, etc.
Blue-Eyed Devil|12.12.07 @ 10:08PM|#
Humans alive today are as different from people living 5,000
years ago as they were from Neanderthals?! Fascinating
...as different genetically for what that is worth.The
truly profound change is culture
which isn't transmitted genetically.I don't doubt a Neanderthal
baby raised by well-off educated parents could succeed in today's
world as well as anyone.
If you are still in Bali order a mushroom pizza
Blue-Eyed Devil|12.12.07 @ 10:13PM|#
I wonder how much genetic change there has been in rats (roof and norway) as they tagged along for the ride?
|12.12.07 @ 10:24PM|#
>>>>I don't doubt a Neanderthal baby raised by
well-off educated parents could succeed in today's world as well as
anyone.
BED, this is not borne out by observation, and I speculate that
culture and genetics will be shown to have much more in common than
you say -- Genetics leading to a culture which often reinforces the
genetics.
happy to dig some links up for you if you like.
|12.12.07 @ 10:25PM|#
People are all exactly alike. There's no such thing as a race
and barely such a thing as an ethnic group. If we were dogs, we'd
be the same breed. George Bush and an Australian Aborigine have
fewer differences than a Lhasa apso and a toy fox terrier. A
Japanese raised in Riyadh would be an Arab. A Zulu raised in New
Rochelle would be an orthodontist. People are all the same, though
their circumstances differ terribly.
-P.J. O'rourke
|12.12.07 @ 10:38PM|#
OK, Ron, that has to be the most boring disclosure ever.
Somehow, I'm guessing that you're closer to a Neanderthal than a
lot of the people living 5,000 years ago.*
*And, by the way, if you had bothered to read what that Hawks dude
said, it was "more different".
Franklin Harris|12.12.07 @ 10:39PM|#
Humans alive today are as different from people living 5,000 years ago as they were from Neanderthals?!
So, does this mean a person from today couldn't mate with an
ancient Mesopotamian? 'Cause this might be relevant to one of the
many time-travel stories I'm procrastinating over.
|12.12.07 @ 10:44PM|#
Blue-Eyed Devil -- Who the heck is Flemur?
Eryk -- I like P. J. O'Rourke's humor, but anyone who has been in
love with one person and repulsed by another would have to take
exception to the notion that we're all identical. Though,
genetically, there's considerably more difference between two
randomly selected blacks in Africa, where humanity originated,
than, say, two Japanese. Even so, we're only talking about 1% or
less differences in genes between the most diverse humans
imaginable -- say, a four-foot tall pygmy in the Congo and a six
and a half foot talk blue-eyed blond Norwegian. What a difference a
few genes can make!
|12.12.07 @ 10:46PM|#
Diversification of the gene pool is inevitable as the population
increases and more genetic lines are perpetuated.
I haven't read the article yet, but evolution depends both on
variation AND selection.
The gene pool may be broader, but is there any evidence that
selection within that gene pool has taken place? 3.9 million
variations implies that there has not been much selection.
|12.12.07 @ 10:52PM|#
So, does this mean a person from today couldn't mate with an
ancient Mesopotamian? 'Cause this might be relevant to one of the
many time-travel stories I'm procrastinating over.
I'm sure we could MATE -- the critical differentiation between
species is the ability to produce offspring capable of reproducing,
not the ability to fit the sticky parts together. We would almost
certainly be genetically compatible with ancient Mesopotamians --
it takes a heck of a lot of physical changes to make for genetic
incompatibility, all the "races" on earth can still readily
interbreed despite being the groups being physically separated for
long stretches from each other, and the people in the most ancient
literature imaginable seem to have essentially the same motivations
and desires of people now.
|12.12.07 @ 10:57PM|#
Franklin Harris
Alone of the great apes, humans have only 23 chromosomes. All the
other great apes have 24. This change arose sometime after the
split between humans and chimps, possibly as early as the
australopithicenes.
Other than this single significant change (which probably precludes
human/chimpanzee chimeras), we are closer to the apes than any of
the equines - horse, donkey, ass, zebra - are to each other. The
equines can all be cross bred, sometimes with fertile
offspring.
So, as long as your kinky time-travellers are mating with genus
homo - homo habilis, homo neanderthalis, homo sapiens -
they should produce offspring. Probably fertile offspring.
|12.12.07 @ 10:59PM|#
The gene pool may be broader, but is there any evidence that
selection within that gene pool has taken place? 3.9 million
variations implies that there has not been much
selection.
Of course selection has occured. Right now, for example, there is
sexual selection based on body weight -- very obese women who
aren't well adapted to our calorie-rich environment are more likely
to end up childless (or dying young of heart disease, etc.) than
physically fit women. People lacking the ability to make rapid
decisions at high velocities are more likely to die in car
accidents. People who don't much care for children are likely to
have none of them due to birth control. Bill Gates would likely not
have thrived in an earlier era lacking computers. People are
adapting to technology and culture changes.
|12.12.07 @ 11:03PM|#
3.9 million variations implies that there has not been much
selection.
In a species with only a 1,000 members, sure. But in a species with
6.5 billion members, we're talking about less than 1 variation per
thousand members. We're not all that genetically diverse as a
species -- we're just used to spotting the slight differences,
because those differences matter.
Blue-Eyed Devil|12.12.07 @ 11:12PM|#
Blue-Eyed Devil -- Who the heck is Flemur?
A somewhat regular commenter here who holds amusing interesting--
you could say controversial -- ideas that I think are entirely
wrong.
IIRC his handle is Mr F Le Mur
|12.12.07 @ 11:31PM|#
Blue-Eyed Devil -- so which of my ideas do you think are
amusing, interesting, and entirely wrong? And what replacement
ideas would you say are more correct?
I'm curious, since nothing I've said above appears to be strikingly
original stuff -- it's all stuff Ive picked up in college while
majoring in biology, plus subsequent reading in science-oriented
magazines like Discover or Scientific American.
|12.12.07 @ 11:31PM|#
prolefeed
I would agree that selection is occurring, but the factors you
list, and even the profound environmental changes that have taken
place since the development of agriculture, have simply not had
enough time to winnow out the less successful variations. (Only
about 500 generations - which is an eyeblink, relatively speaking)
Our species has been astonishingly successful primarily because we
are the first to occupy what could be called the "sapient niche" in
the environment. We simply have not been heavily culled - except in
our immune system - since the agricultural revolution.
|12.12.07 @ 11:41PM|#
I've read that cro magnan man was taller and had a larger
cranial capacity than modern humans. Neanderthals also had a larger
brain, and were about three times stronger than us.
It would be interesting to see some scientist conduct a synthesis
of this latest revelation of rapid human evolution with the
apparent devolution that occured before the appearance of
civilization.
|12.12.07 @ 11:51PM|#
Aresen -- I agree that when biologists talk about "rapid"
evolution, they usually aren't talking about timespans of decades
or even a few centuries. When you have a population of 6.5 billion,
you're going to have ongoing evolution, but the sheer size of the
gene pool buffers things -- that is, it's hard to entirely wipe out
a gene in the "short" time span of a few human lifetime -- you're
talking more about changing the relative frequencies of genes. It's
been posited that really rapid, dramatic changes in a species or
even the formation of an entirely new species usually happens when
a population dwindles down to a handful of individuals, so it's
possible to entirely eliminate genes or cause a new gene to
predominate in one or two generations.
"Culling" of genes can occur both through death and births. If, as
is the case now in developed countries, hardly anyone dies young,
selection shifts more toward the ability to have more offspring.
For example, the offspring of the siblings of Joseph Smith are very
thoroughly documented -- Hyrum and Joseph Smith have tens of
thousands of descendents, while some of their other siblings have
only a dozen or so descendents. All of them have genes persisting
in the gene pool, but the relative frequencies have changed by
several orders of magnitude in a geological eyeblink.
Franklin Harris|12.12.07 @ 11:52PM|#
So, as long as your kinky time-travellers are mating with genus homo - homo habilis, homo neanderthalis, homo sapiens - they should produce offspring. Probably fertile offspring.
They're not kinky time travelers because they're potentially having
sex with humans from just 5,000 years ago. Although, as I've now
learned, those people were supposedly sufficiently different from
us that it might now indeed be kinky, which isn't what I had in
mind.
|12.13.07 @ 12:00AM|#
Another thing to remember is that we are fast approaching the day when we as a species take control of our genes, rather than the other way around. Whatever your opinion of the rate of recent evolution, natural evolution will probably end within our lifetimes.
|12.13.07 @ 12:09AM|#
Some comment-relevant passages from the University of Wisconsin news
story for those that didn't read it...
In a study published in the Dec. 10 issue of the Proceedings of the National Academy of Sciences (PNAS), a team led by UW-Madison anthropologist John Hawks estimates that positive selection just in the past 5,000 years alone - around the period of the Stone Age - has occurred at a rate roughly 100 times higher than any other period of human evolution.
. . .
While more than 99 percent of the human genome is common across all humans, the HapMap project is cataloguing the individual differences in DNA called single nucleotide polymorphisms (SNPs). The project has mapped roughly 4 million of the estimated 10 million SNPs in the human genome.
. . .
[T]he researchers found evidence of recent selection on approximately 1,800 genes, or 7 percent of all human genes.
This finding runs counter to conventional wisdom in many ways, Hawks says. For example, there's a strong record of skeletal changes that clearly show people became physically smaller, and their brains and teeth are also smaller. This is generally seen as a sign of relaxed selection - that size and strength are no longer key to survival.
But other pathways for evolution have opened, Hawks says, and genetic changes are now being driven by major changes in human culture.
. . .
The recent changes are especially striking, he says. "Five thousand years is such a small sliver of time - it's 100 to 200 generations ago," he says. "That's how long it's been since some of these genes originated, and today they are in 30 or 40 percent of people because they've had such an advantage. It's like 'invasion of the body snatchers.'"
|12.13.07 @ 12:13AM|#
Another thing to remember is that we are fast approaching
the day when we as a species take control of our genes, rather than
the other way around.
I sincerely hope that's not the case, since saying a "species take
control of our genes" implies a government taking control and
implementing an agenda designed to further political ends. If you
meant when we as individuals take control, I'm
fine with that, though anyone who has played BioShock can envision
a few *minor* downsides from when we all become Splicers.
Lucas|12.13.07 @ 12:16AM|#
"I would agree that selection is occurring, but the factors you
list, and even the profound environmental changes that have taken
place since the development of agriculture, have simply not had
enough time to winnow out the less successful variations. (Only
about 500 generations - which is an eyeblink, relatively
speaking)"
A back of the envelope calculation I did showed the
following:
Assuming that everyone has (on average) 1.15 children, except for
1/10 % of people with an allele which gives them 1% more offspring,
in 500 generations, that allele will make up about 12% of the
population--not exactly small potatoes. If 5 percent of the
population has that allele, then they will make up 88% of the
population after 500 generations. Of course the situation is much
more complicated than my model, but I'm a mathematician, not a
mathematical biologist. From what I've read in Dawkins' books,
comparatively small differences can make a huge difference in the
population after a surprisingly small amount of time.
I would imagine that the most profoundly selected alleles would be
those for fighting disease. I wonder how much of this selection
relates to disease.
D.A. Ridgely|12.13.07 @ 12:21AM|#
I don't doubt a Neanderthal baby raised by well-off educated
parents could succeed in today's world as well as
anyone.
[insert George W. Bush joke here]
|12.13.07 @ 12:23AM|#
I would imagine that the most profoundly selected alleles
would be those for fighting disease.
And you would be right. We've eliminated or marginalized most of
the large predators, but the little microscopic ones loom large.
Humans (and other species) have been shown to have an uncanny knack
for spotting which potential mates have immune systems most
different from ours, and finding that difference sexy and
attractive.
|12.13.07 @ 12:26AM|#
I wonder how much of this selection relates to
disease.
From the same article cited above:
The biggest new pathway for selection relates to disease resistance. As people starting living in much larger groups and settling in one place roughly 10,000 years ago, epidemic diseases such as malaria, smallpox and cholera began to dramatically shift mortality patterns in people. . .
Another recently discovered gene, CCR5, originated about 4,000 years ago and now exists in about 10 percent of the European population. It was discovered recently because it makes people resistant to HIV/AIDS. But its original value might have come from obstructing the pathway for smallpox.
|12.13.07 @ 12:28AM|#
Brian Coutts
Thanks. Now that is interesting. It tends to support prolefeed's
position more than mine. For a gene to go from the initial mutation
to 30% of the population in a couple of hundred generations implies
a huge selective advantage. This is especially true, as prolefeed
noted in his 11:51 post, when the population size is so huge.
prolefeed @ 12:13
I agree that the thought of a government attempt to control the
gene pool is frightening. I wouldn't mind it if individuals were
selecting their own preferences for their own offspring.
However, I expect that there would be an alliance between the
Religious Fundamentalists - of all faiths - and the luddites of
both left and right to put selection under government control.
grylliade|12.13.07 @ 12:39AM|#
"Ten thousand years ago, no one on planet Earth had blue eyes," Hawks notes, because that gene-OCA2-had not yet developed.
Hah! Then how did Jondalar and Ayla have blue eyes, Mr.
Smarty-pants?
|12.13.07 @ 1:01AM|#
Aresen -- one would have to be terribly naive that think that
politicians that feel compelled to micromanage what kinds of fat we
can eat, how much gas mileage our cars must get, and what kinds of
chemicals we can ingest -- would go "oh, we have no business
putting any controls on people tinkering with their genomes"
It wouldn't just be the fundies and the luddites butting in here --
it'd be secular liberals and everyone else not libertarian in
outlook thinking we must regulate it for the sake of Teh Children
TM.
|12.13.07 @ 1:06AM|#
prolefeed
Agree 100% on your 1:01 AM post.
Fun talking to ya, but I am off to bed.
g'night.
|12.13.07 @ 1:31AM|#
Disclosure: My eyes are brown, but some of my best friends
are blue-eyed and some others have green eyes.
Regardless of how this might have evolved, obviously the most
attractive, mate-worthy males have green eyes.
disclosure: I have green eyes
The Wine Commonsewer|12.13.07 @ 1:37AM|#
"Ten thousand years ago, no one on planet Earth had blue
eyes," Hawks notes, because that gene-OCA2-had not yet
developed.
The people from the 12th Planet brought blue eyes and Siamese cats
with them. They hadn't arrived 10k years ago. They arrived about
the time of Sumeria.
Mike Huckabee|12.13.07 @ 2:40AM|#
Of course there were no blue eyes 10,000 years ago since God
hadn't even created the Earth yet.
But hey, "if you want to believe that you and your family came from
apes, I'll accept that..."
|12.13.07 @ 9:10AM|#
I would imagine that the most profoundly selected alleles would be those for fighting disease.
And you would be right. We've eliminated or marginalized most of the large predators, ...
Devil's advocate here. How about those useful for fighting, and
killing each other, including intelligence? There is certainly one
large predator that we haven't eliminated or marginalized. Yes the
black death killed 1/3 of the Europeans in a generation, but
intraspecies violence takes it's toll generation after generation.
Historically, people who are successful at war outbreed the
losers.
This science is way above my pay grade so I'm just musing here.
Please feel free to blast the hypothesis to smithereens as you all
probably will.
robc|12.13.07 @ 9:27AM|#
The ability to control our genes reminds me of something I saw
in at least one Niven novel - the concept that tool users dont
evolve. Tool users dont adapt to their environment, they adapt
their environment to them.
This obviously isnt completely true, see the CCR5 example mentioned
above. However, which has done more to allow us to survive
diseases, gene mutation or man-made vaccines/drugs/etc? CCR5 didnt
wipe out the threat of smallpox, man did. We didnt need to evolve
more hair to live in cold climates, we learned to burn stuff
instead.
Genes are still mutating. But ingenuity is faster than
mutation.
|12.13.07 @ 9:27AM|#
Adding to my previous, anyone who's ever looked at a bower birds
behaviour quickly realizes that sexual selection plays a very large
role in evolution. Since the development of intelligence, hanvn't
humans mate preferences changed as society changes? Would Bill
Gates be considered a more desireable better mate than Bruno the
bouncer 3,000 years ago? IMHO, that's unlikely.
IOW, genes drive behavior, do intelligence, technology and culture,
speed up sexual selection evolutionary change?
Fascinating stuff, for sure.
|12.13.07 @ 9:55AM|#
How about those useful for fighting, and killing each other,
including intelligence?
Disease has historically been more effective at eliminating enemies
than swords or cleverness.
Following disease has been technology. Technological advance is
more driven more by culture than (relatively minor) differences in
intelligence.
It doesn't matter how big, strong, or clever the other guy is if
you have a bow and arrow, or iron weapons, and he does not.
|12.13.07 @ 10:01AM|#
Disease has historically been more effective at eliminating
enemies than swords or cleverness.
Diseases eliminate people, friend or foe. War eliminates
enemies.
It doesn't matter how big, strong, or clever the other guy is
if you have a bow and arrow, or iron weapons, and he does
not.
I would venture that "clever" has somthing to do with, the bow and
arrow, iron smelting, the Greek phalanx, and the Roman legion.
grylliade|12.13.07 @ 10:09AM|#
The ability to control our genes reminds me of something I saw in at least one Niven novel - the concept that tool users dont evolve. Tool users dont adapt to their environment, they adapt their environment to them.
This obviously isnt completely true. . .
That's from The Mote in God's Eye, in which it was a plot
point that the Moties evolved after they'd been
technologically advanced. I just re-read that, and it struck me
that, given the science of the times, it was a reasonable position
to take. It was written and published in the '70s, before the major
revolutions in genetic science that took place in the '80s. IIRC,
the idea of genetic drift wasn't widespread before the '80s, if it
even existed. If evolution only occurred through natural
selection, then technology would slow the rate of evolution, and
eventually halt it altogether. However, given genetic drift and
other mechanisms, evolution certainly still occurs in
technologically advanced species.
Note that it would take antibiotics, at least, to halt evolution
given the above assumptions. :-)
robc|12.13.07 @ 10:22AM|#
grylliade,
Im thinking Niven mentioned it in The Locusts too. Which
is also (like Mote) a story in which it turns out to not be true.
Not sure on that reference though, there is at least 1 other
mention of it by Niven. Maybe in What Can You Say About
Chocolate Covered Manhole Covers?
robc|12.13.07 @ 10:28AM|#
Speaking of Niven and Manhole Covers I have a very-unpc confession to make (not that I ever cared about being politically correct). Early in his career, whenever their was a discussion of "Why is Tiger Woods so good?" I wanted a talking head to suggest hybrid vigor. But they never did.
robc|12.13.07 @ 10:30AM|#
Note that it would take antibiotics, at least, to halt
evolution given the above assumptions.
Alexander Fleming ended evolution!
stuartl|12.13.07 @ 10:34AM|#
I would venture that "clever" has somthing to do with, the
bow and arrow, iron smelting, the Greek phalanx, and the Roman
legion.
...and building ocean worthy vessels, calculating trajectories of
projectile weapons, building aircraft, creating and breaking codes,
nuclear weapons, ....
IIRC, the idea of genetic drift wasn't widespread before the
'80s, if it even existed.
In the late 60s I did a junior high science fair project on genetic
drift and how selection factors interact with drift, so it couldn't
have been that unusual a concept.
|12.13.07 @ 10:38AM|#
Diseases eliminate people, friend or foe. War eliminates
enemies.
Disease eliminates whole peoples who don't have resistance to the
disease. Just ask the Native Americans. Without the diseases
Pizarro and Cortez brought with them, they could not have
overthrown the essentially neolithic Aztec and Incan empires, in
spite of their technological advantages.
When you're talking about selectors of who gets to reproduce after
a conflict, disease outweighs killing on the battlefield
manifold.
I would venture that "clever" has somthing to do with, the bow
and arrow, iron smelting, the Greek phalanx, and the Roman
legion.
Cleverness is an individual trait. The cleverness of a few
individuals doesn't sustain the kind of technological change that
gives decisive advantages in warfare nearly as much as culture
does.
The phalanx was developed over generations of constant conflict
among Greek city-states, and was the product not of a brainwave by
a general or two, but of the societal structure of the area and of
numerous technologies. You couldn't have a phalanx of stone-age
tribesmen, so even if a neolithic Leonidas had the inspiration, he
couldn't have made it work.
First Little Pig|12.13.07 @ 10:41AM|#
And when we can take control of our genes I want to be the first
to form the Iron Society.
And if you get that reference you get a free "Total Geek"
t-shirt.
|12.13.07 @ 11:25AM|#
prolefeed:
Blue-Eyed Devil -- Who the heck is Flemur?
Dats me. I sometimes write things which people who're unfamiliar
with genetics find distressing.
What a difference a few genes can make!
Yup. FWIW, current guestimates are that humans are about
98.something% genetically the same as chimps and about 80%
genetically the same as mice.
FWIW, over the past couple of years, I've become a somewhat of a
fan of two of this paper's authors.
John Hawks comments on (rather complicated) criticisms of the
paper. Also, if you're into Neandertals (his preferred spelling)
and possible interbreeding with humans, poke around the rest of his
site. (Look for "red hair"...). He updates just about every
day.
Another author's (Cochran) site is here. He thinks outside the box, so
to speak.
|12.13.07 @ 11:33AM|#
Cleverness is an individual trait. The cleverness of a few
individuals doesn't sustain the kind of technological change that
gives decisive advantages in warfare nearly as much as culture
does.
I knew this was coming. In war, every participants "cleverness"
matters in the battle. The "clever" survive and the dull perish.
War, as a byproduct, winnows out the stupid and unfit.
|12.13.07 @ 12:21PM|#
Historically, people who are successful at war outbreed the
losers.
J sub D -- The definition of "losers", from a strictly genetic POV,
is "someone who fails to get enough (or any) genes into the next
generation". Evolution doesn't care about aesthetics, just results.
So, a single mom with 10 kids and no fathers who stuck around,
struggling from welfare check to welfare check, is a big winner
from a genetic standpoint, at least for that generation, however
much we might consider her a loser by another other criteria.
Aaaand, in regards to warfare, if you get killed in Iraq, but have
five kids before that happens, genetically speaking you're a
winner. If you were a draft dodging hippie and had a lot of kids
because you didn't die in Vietnam, you're a winner. But the draft
dodger who didn't have any kids because they ducked the draft by
getting hooked on heroin and then couldn't attract a stable mate is
a loser. If you die childless but win the Medal of Honor,
genetically you're a loser compared to a coward who bolted under
fire and lived to make it back home.
So, "successful at war" can mean lots of counterintuitive
things.
|12.13.07 @ 12:28PM|#
Note that it would take antibiotics, at least, to halt
evolution given the above assumptions.
Antibiotics don't halt evolution, they increase
the rate of evolution. The pathogens evolve faster because they are
heavily selected for resistence to antibiotics -- look at how fast
antibiotics have been made obsolete by resistant strains. And,
antibiotics also ramp up human evolution, since they change the
environment, giving smaller rewards to those with genetic
resistence to the disease controlled by the antibiotics and
rewarding those who genomes aren't wasting energy and resources on
combatting a disease that is no longer around. It is genetically
costly to defend against a threat that no longer exists.
|12.13.07 @ 12:36PM|#
Diseases eliminate people, friend or foe. War eliminates
enemies.
Disease used to be the big killer on battlefields. Not so much now.
The genetic selection in warfare has changed over time. If you read
the Old Testament, a lot of genocide going on -- on several
occasions the alleged Lord allegedly commanded the Israelites to
utterly wipe out their defeated enemies, so a gene unique to a
tribe could be utterly wiped out if that tribe was slaughtered to
the last person. In a less tribal world, where the opposing sides
have a mix of nationalities, and where the losers don't face
annihilation, selection is less on a group or societal or cultural
level and more on an individual level.
Neu Mejican|12.13.07 @ 12:57PM|#
Something which hasn't been brought up yet...
Although cultural adaptations have led to increased numbers of
humans in increasingly difficulty environmental niches over the
course of our history as a species...and increased dispersal has
led to geographically distinct populations (genetically), there is
little evidence that aspects of culture provides niche pressures
for particular genetic traits. Cultural adaptation is too fast and
ephemeral to provide selection pressure for the relatively slow
genetic changes. By the time a significant number of individuals
had adapted to the cultural niche, it wouldn't be there anymore.
The cultural environment presents to quickly moving a target for
genetic adaptations.
A nice paper on this basic idea related to the development of
language by our species.
http://www.santafe.edu/research/publications/workingpapers/07-01-001.pdf
Neu Mejican|12.13.07 @ 1:09PM|#
FleM,
Dats me. I sometimes write things which people who're
unfamiliar with genetics find distressing.
You also sometimes write things which people who are familiar with
neuroscience find uninformed.
And you also sometimes write things which people familiar with the
heredity of intelligence find unsupported.
|12.13.07 @ 2:30PM|#
In war, every participants "cleverness" matters in the
battle.
It doesn't matter how clever you are if you are hoisting a rock and
your opponent is drawing a bow.
Whether you have a rock or a bow is a matter of the culture you are
part of, not how smart you are as a person.
Few people would argue that, weapon for weapon, the Germans had
marginally better technology in WWII. Few would argue that, officer
for officer, the Germans were at least as well led as the allies.
If cleverness was decisive, it seems to me they would have
won.
The "clever" survive and the dull perish.
On an individual level, maybe. But when you are looking at a scale
that can influence cultural and genetic winners, that individual
level doesn't count for much, really.
|12.13.07 @ 3:29PM|#
Between the lines of this posting is the obvious: INDUSTRY is
not responsible for global warming, Agriculture is!
"We believe that this can be explained by an increase in the strength of selection as people became agriculturalist
Isn't it obvious all our woes began with farming?
|12.13.07 @ 3:45PM|#
Prolefeed said:
Even so, we're only talking about 1% or less differences in
genes between the most diverse humans imaginable -- say, a
four-foot tall pygmy in the Congo and a six and a half foot talk
blue-eyed blond Norwegian.
Even if that 1% crude estimate which is sometimes bandied about is
correct, it's extremely misleading. By the same sort of estimate
we're only 3% different genetically from chimpanzees, who cannot
speak and have no sophisticated language, and way less than 50%
genetically different from earthworms.
It might well take only .001% genetic difference to separate a 165
IQ genius from a 70 IQ dullard, or someone with olympic champion
100 meter fast twitch leg muscles from a weak and ill co-ordinated
person of the same age who can barely run at all.
Human subgroups (aka races and subraces) are among the most
genetically various sub species in the mammalian world; and hardly
among the least so, as some have claimed for what one must suppose
are ideological imperative reasons.
|12.13.07 @ 3:54PM|#
J sub D -- The definition of "losers", from a strictly
genetic POV, is "someone who fails to get enough (or any) genes
into the next generation".
No shit, Sherlock. Surving in war only slightly advances
your chance of passing on your particular genes. Bigger ears only
slightly helps an individual elephant to survive. If the
rabbit gets eaten by the coyote after she's delivered 6
litters she's a winner in the genetic sense. Yet somehow over tome,
rabbits developed those muscular legs and keen senses anyway. Maybe
because those features slightly improve their chance of
survival and breeding. It wasn't that some reptile mutation
suddenly appeared with the ability to fly, rather it was small
steps that slightly improved chances of survival and
breeding.
Neu Mejican|12.13.07 @ 5:36PM|#
dougjn,
Human subgroups (aka races and subraces) are among the most
genetically various sub species in the mammalian world; and hardly
among the least so, as some have claimed for what one must suppose
are ideological imperative reasons.
Do you happen to have a citation for that fact.
It hangs out there like a sore thumb begging for support from some
external source.
Neu Mejican|12.13.07 @ 5:52PM|#
dougjn,
Here's the only thing I could come up with on a quick search:
http://www.nature.com/ng/journal/v36/n11s/full/ng1435.html
The average proportion of nucleotide differences between a
randomly chosen pair of humans (i.e., average nucleotide diversity,
or pi) is consistently estimated to lie between 1 in 1,000 and 1 in
1,500 (refs. 9,10). This proportion is low compared with those of
many other species, from fruit flies to chimpanzees11, 12,
reflecting the recent origin of our species from a small founding
population13.
Neu Mejican|12.13.07 @ 6:02PM|#
dougjn,
Modern human genetic variation does not structure into
phylogenetic subspecies (geographical 'races'), nor do the taxa
from the most common racial classifications of classical
anthropology qualify as 'races'
http://www.nature.com/ng/journal/v36/n11s/full/ng1455.html
|12.13.07 @ 8:40PM|#
Neu Mejican:
You also sometimes write things which people who are familiar
with neuroscience find uninformed.
And you also sometimes write things which people familiar with the
heredity of intelligence find unsupported.
All my statements on those subjects are based on current science,
but, since a lot of it's new, a fair amount is subject to
disagreement within the various fields - and, in some cases,
research is also subject to politically based
suppression. Sorry about your distress, though.
Neu Mejican|12.13.07 @ 9:50PM|#
FleM,
It does not distress me that you are uninformed and make
unsupported claims.
As for "politically based suppression" of intelligence research,
well that's just more unsupported silliness.
|12.14.07 @ 7:47AM|#
Few people would argue that, weapon for weapon, the Germans
had marginally better technology in WWII. Few would argue that,
officer for officer, the Germans were at least as well led as the
allies. If cleverness was decisive, it seems to me they would have
won.
Depends how you define "cleverness." In terms of German officers
may have been as "clever" or more so than Allied officers, but
German logistics were quite far from "clever." US soldiers also
tended to be more flexible, adaptable and resourceful in the field,
even if probably not as good as Germans in actual combat. Over the
course of the war this difference in "clever" played a decisive
role.
Neu Mejican|12.14.07 @ 10:45AM|#
FleM,
So do you consider Nisbett's critique of Jensen political or
scientific in nature?
http://www.udel.edu/educ/gottfredson/30years/Nisbett-commentary-on-30years.pdf
Is this post political or scientific in nature?
http://www.cscs.umich.edu/~crshalizi/weblog/520.html
Politics or science?
http://www.wjh.harvard.edu/soc/faculty/winship/IQ.pdf
Science or politics?
http://content.apa.org/journals/rev/108/2/346
No link, but as an example of how suppression does not happen in
the field of IQ genetics...
A longitudinal twin study on IQ, executive functioning, and
attention problems during childhood and early adolescence.
Polderman TJ, Gosso MF, Posthuma D, Van Beijsterveldt TC, Heutink
P, Verhulst FC, Boomsma DI. Acta Neurol Belg. 2006
Dec;106(4):191-207.
No serious scientist doubts that genetics play a role in IQ. The
case for racial contributions to IQ is, however, very weak.
It is an easy accusation to say that someone disagrees with the
science because they are afraid of the implications of the ideas it
represents. That accusation, however, is not a way to support the
science. I can find your idea both scientifically incorrect AND
politically incorrect. The second has nothing to do with the
first.
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