Archives for posts with tag: evolution by natural selection

in Experimenting with Social Norms ensminger and henrich compile several very interesting studies on prosocial “fairness” norms conducted on various populations of different types — ranging from hunter-gatherers to urban factory workers — from around the world. three different economic experiments were conducted on the various populations (although it’s not clear to me if all three were run on each group — i haven’t read through all of each of the studies chapters yet): the ultimatum game, the third-party punishment or altruistic punishment game, and the dictator game.

the authors conclude that [pgs. 89-90]:

“1. Fairness and punishment show both reliable patterns and substantial variability across diverse populations.
2. Fairness increases with a population’s degree of market integration.
3. Fairness increases with an individual’s participation in a world religion.
4. Willingness to engage in punishment increases with community size.”

they ultimately conclude “that social norms evolved over thousands of years to allow strangers in more complex and large settlements to coexist, trade and prosper” — but they just mean that the norms and the cultures evolved, not the peoples.

possible biological/evolutionary reasons for the findings are given some consideration, but only across one and a half pages, and the authors end with the following [pg. 139]:

“Genetic differences between populations or groups would most likely account for the behavioral patterns we observe if they arose in response to stable differences in the culturally evolved social norms and institutions (formal and informal) found in different societies. Norms and institutions, in creating stable regularities in the local social environment, can theoretically produce conditions for natural selection to act on genes that make individuals better adapted to those particular norms and institutions (Henrich and Boyd 2001; Laland et al. 2010; McElreath, Boyd, and Richerson 2003; Richerson et al. 2010). This is an intriguing and provocative possibility, but there is no evidence at this point supporting a suspicion that such a culture-gene coevolutionary process has occurred.”

…and it’s too scary to think about anyway, so we won’t give it any more ink here. (>.<)

in 2010, re. pretty much the same data sets/findings, they had this to say [my emphasis]:

“These findings indicate that people living in small communities lacking market integration or world religions — absences that likely characterized all societies until the Holocene — display relatively little concern with fairness or punishing unfairness in transactions involving strangers or anonymous others. This result challenges the hypothesis that successful social interaction in large-scale societies — and the corresponding experimental findings — arise directly from an evolved psychology that mistakenly applies kin and reciprocity-based heuristics to strangers in vast populations (4,5), without any of the ‘psychological workarounds’ (42) that are created by norms and institutions. Moreover, it is not clear how this hypothesis can explain why we find so much variation among populations in our experimental measures and why this variation is so strongly related to MI, WR, and CS. The mere fact that the largest and most anonymous communities engage in substantially greater punishment relative to the smallest-scale societies, who punish very little, challenges this interpretation.”

this is old school evolutionary psychology at its worst — that human nature and the human psyche (and there’s only one sort in this viewpoint) stopped evolving at the end of the last ice age when a majority of us quit being hunter-gatherers.

well, i’ve got news for them: evolution in humans is ongoing, recent, can be pretty rapid (within some constraints), and has been/is localized (as well as global). in fact, human evolution has sped up since the agricultural revolution since the number of individuals, and therefore mutations, on which natural selection might work skyrocketed in post-agricultural societies.

remember, too, that all human behavioral traits are heritable (and more down to biology than many like to think), “every society selects for something,” and that we’re talking about frequencies of genes in populations and that those frequencies can fluctuate up and down over time.

given all of the above, there are NO good reasons for dismissing genetic or evolutionary explanations for variations in social norms between populations (and individuals for that matter). since we are biological creatures, biological explanations should be ruled out (properly!) first before moving on to other sorts of explanations.

again ensminger and henrich said:

“This result challenges the hypothesis that successful social interaction in large-scale societies — and the corresponding experimental findings — arise directly from an evolved psychology that mistakenly applies kin and reciprocity-based heuristics to strangers in vast populations, without any of the ‘psychological workarounds’ that are created by norms and institutions.”

no, of course not. a more likely scenario is that the behavioral traits realted to social norms in large-scale societies — post-agricultural societies (and post-post-agricultural societies) — evolved with some rapidity away from what had existed before in smaller societies thanks to: 1) the larger population size itself (generating a greater number of mutations), and 2) the larger societies and the structures that developed exerting new selective pressures on those populations in sort-of giant feedback loops — society selects for genes for new behavioral traits which in turn produces new societal forms, and so on.

more from the authors:

“Moreover, it is not clear how this hypothesis can explain why we find so much variation among populations in our experimental measures….”

well, that’s easily explained if you remember that human evolution is ongoing, recent, pretty rapid, and can be local.

to take just one example from their findings, if we look at their results from the dictator game…

mean dictator game offers

…it was primarily members of the hunter-gatherer or horticulturalist groups who gave low offers in the game, african agriculturalists (or pastoralists) middling offers, and the residents of hamilton, missouri, the highest. (annoyingly, a couple of the populations — accra and isanga — are groups of mixed ethnicities, so it’d be difficult for anybody to tease apart what’s going on.)

well, hunter-gatherers and horticulturalists — like the hadza, the tsimane’, the au, and the sursurunga — have largely missed out on the agricultural revolution and its evolutionary effects. the middling offers from the mostly african (mostly bantu) agriculturalists are not a surprise either since agriculture and the development of large-scale societies got going comparatively late in sub-saharan africa. and that the hamiltonians offered up the most money — and have the highest market integration — probably owes a lot to the fact that that population is a part of the u.s. midlands and are descended from a group that experienced the agricultural revolution back in the neolithic, and furthermore went through the selection pressures created by medieval manorialism and long-term outbreeding (and who knows what else?).

those are just a few ideas for starters. i’m sure it’s much more complicated than that. for instance, why are the tsimane’ forager-horticulturalists so stingy while the au from papua new guinea, who are also forager-horticulturalists, quite generous? i dunno, but one possibility i suggest checking out is the difference in the family structures of the two groups (prolly will be difficult to do this very far back in time): the interconnectedness of au families, which stretch between villages, is quite complex, while tsimane’ families are not so much (afaik). among many other possibilities and scenarios, we should be looking for the selection pressures created by family types and the flow of genes (especially for behavioral traits like altruism) through different family types.

one final thing – ensminger and henrich et al. from 2010:

“Methodologically, our findings suggest caution in interpreting behavioral experiments from industrialized populations as providing direct insights into human nature.”

well, quite. but it works in the other direction, too: we should also be cautious in interpreting behavioral experiments from non-industrialized populations as providing direct insights into human nature(s).

see also: The 10,000 Year Explosion

(note: comments do not require an email. citizens against prosocial behaviors.)

What Your DNA Says About Medieval History“A new study uses genetic data from living people to trace millennia-old migration patterns…. [M]uch of what Capelli and his colleagues discovered meshed with what historians already knew. For example, among northern Europeans, highest rate of admixing took place ‘around the late first millennium C.E., a time known to have involved significant upheaval in Europe,’ while admixture between north African and southern European populations was dated to a time span ‘consistent with migrations associated with the Arabic Conquest of the Iberian peninsula.’ But there were surprises, too. Most notably, Capelli and his colleagues discovered evidence for an influx of Mongolians into Europe that predated the reign of Ghengis Khan.” – orig. research article: The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape.

Inuit Study Adds Twist to Omega-3 Fatty Acids’ Health Story“A study published on Thursday in the journal Science reported that the ancestors of the Inuit evolved unique genetic adaptations for metabolizing omega-3s and other fatty acids. Those gene variants had drastic effects on Inuit’s bodies, reducing their heights and weights. Rasmus Nielsen, a geneticist at the University of California, Berkeley, and an author of the new study, said that the discovery raised questions about whether omega-3 fats really were protective for everyone, despite decades of health advice. ‘The same diet may have different effects on different people,’ he said…. The researchers found several genetic variants at different locations in the genome that were unusually common in the Inuit, compared with people in Europe or China. Several of these variations occurred within a cluster of genes that direct construction of enzymes called fatty acid desaturases. (The genes are called FADS, for short….) Even more intriguing was the fact that one of these gene variants was present in almost every Inuit in the study. It is much less common in other populations: About a quarter of Chinese people have it, compared with just 2 percent of Europeans. Natural selection is the only known way this gene variant could have become so common in the Inuit. Dr. Nielsen said this adaptation might have arisen as long ago as 20,000 years, when the ancestors of the Inuit were living in the Beringia region, which straddles Alaska and Siberia…. The adaptation did more than just change blood levels of fatty acids, the scientists found. Inuit who carried two copies of the variant gene were on average an inch shorter and 10 pounds lighter than those without a copy.” – orig. research article: Greenlandic Inuit show genetic signatures of diet and climate adaptation. see also Your Genes Are What You Eat from razib.

Height-reducing variants and selection for short stature in Sardinia“[K]nown height-decreasing alleles are at systematically higher frequencies in Sardinians than would be expected by genetic drift. The findings are consistent with selection for shorter stature in Sardinia and a suggestive human example of the proposed ‘island effect’ reducing the size of large mammals.” – h/t andrew sabisky!

Are humans still evolving? Yes, both globally and locally. – from jerry coyne.

5 key facts about the nuclear DNA from Sima de los Huesos“If confirmed, the results will push back the H. sapiens-H. neanderthalensis ancestor beyond 400 KYA. Meyer suggested that the ancestors of H. sapiens could have diverged from the branch leading to neandertals and denisovans 550 K to 765 K years ago. It may be possible that H. sapiens evolved in western Eurasia and later migrated back into Africa. The fossils from Europe, Asia and Africa in the 400 Ka. period are physically very diverse and may represent multiple species, only one of which could be the ancestor of today’s humans. For example, Chris Stringer thinks it may be needed to look at Homo antecessor and not Homo heidelbergensis as our last common ancestor with neandertals.”

New DNA tests on ancient Denisovan people ‘shows them occupying Altai cave 170,000 years ago’“Prehistoric Siberians lived in Denisova Cave earlier than scientists realised – new claim based on state-of-the-art technology.” – h/t paleoanthropology!

Origins, admixture and founder lineages in European Roma“We found a set of founder lineages, present in the Roma and virtually absent in the non-Roma, for the maternal (H7, J1b3, J1c1, M18, M35b, M5a1, U3, and X2d) and paternal (I-P259, J-M92, and J-M67) genomes. This lineage classification allows us to identify extensive gene flow from non-Roma to Roma groups, whereas the opposite pattern, although not negligible, is substantially lower (up to 6.3%). Finally, the exact haplotype matching analysis of both uniparental lineages consistently points to a Northwestern origin of the proto-Roma population within the Indian subcontinent.”

Why I’m sceptical about the idea of genetically inherited trauma“A recent scientific paper claiming that the children of Holocaust survivors showed evidence of inherited stress was deeply flawed – here’s why.”

Population genetic differentiation of height and body mass index across Europe“Here we find that many independent loci contribute to population genetic differences in height and body mass index (BMI) in 9,416 individuals across 14 European countries.”

North-South divide, Japanese style – from dr. james thompson.

Genetics of IQ and lifespan and Genius? Avoid rare functional genes and Heritability of Specific Cognitive Abilities and Schizophrenia and cognitive decline and g for Latinos and White matter efficiency predicts women’s IQ, but not men’s – all also from dr. james thompson!

SNP hits on cognitive ability from 300k individuals – from steve hsu. h/t holtz!

Do smart girls postpone first sex? and Do women find bright men sexy? – and even MORE from dr. james thompson!! whew!

Green Arabia’s key role in human evolution“Scientists have been illuminating the vital role played by the Arabian Peninsula in humankind’s exodus from Africa. Far from being a desert, the region was once covered by lush vegetation and criss-crossed by rivers, providing rich hunting grounds for our ancestors.”

The UK10K project identifies rare variants in health and disease – h/t kevin mitchell!

Genetics of aggressive behavior: An overview – h/t brian boutwell!

Sons of the Soil, Migrants, and Civil War“In nearly a third of ethnic civil wars since 1945, the conflict develops between members of a regional ethnic group that considers itself to be the indigenous “sons of the soil” and recent migrants from other parts of the country.” – h/t whyvert!

It’s finally out: The big review paper on the lack of political diversity in social psychology“Psychologists have demonstrated the value of diversity – particularly diversity of viewpoints – for enhancing creativity, discovery, and problem solving. But one key type of viewpoint diversity is lacking in academic psychology in general and social psychology in particular: political diversity.” – from jonathan haidt.

The genetics of alcohol dependence: Twin and SNP-based heritability, and genome-wide association study based on AUDIT scores – h/t amir sariaslan!

Chronotype Associations with Depression and Anxiety Disorders in a Large Cohort Study – h/t emily deans! who tweeted: “‘Morning people’ less likely to be depressed in this large and relatively thorough observational study.” – (morning people depress me. (~_^) )

The Hormone That Bonds Humans to Dogs – h/t old whig! who tweeted: “Evolutionary change is faster than we think? Case study: oxytocin.”

Does the Gender of Offspring Affect Parental Political Orientation? – h/t ben southwood! who tweeted: “Studies on offspring gender & political orientation plagued by publication bias; actually there’s no relationship.”

Do Angry Birds Make for Angry Children? A Meta-Analysis of Video Game Influences on Children’s and Adolescents’ Aggression, Mental Health, Prosocial Behavior, and Academic Performance“Overall, results from 101 studies suggest that video game influences on increased aggression (r = .06), reduced prosocial behavior (r = .04), reduced academic performance (r = −.01), depressive symptoms (r = .04), and attention deficit symptoms (r = .03) are minimal.” – h/t joseph schwartz!

Ancient campfires show early population numbers [in australia]“ANU archaeologist Alan Williams used radio carbon dating technology to examine charcoal dates from more than 1000 prehistoric campfires and based on this he says populations appear to have increased steadily until 25,000 years ago…. After this initial increase, he says, population levels remained steady or even declined from 25,000 years ago, during the more arid Last Glacial Maximum (25,000 to 13,000 years ago) when temperatures were about ten degrees cooler…. Campfire numbers began to grow again 13,000 years ago when the northern wet season re-emerged.”

Aboriginal ‘memories’ of Australia’s coastline go back more than 7,000 years

History became legend, legend became myth: Crater Lake – h/t razib! who tweeted: “8,000 year old explosion preserved in folk memory of klamath indians?”

Ancient Script Spurs Rethinking of Historic ‘Backwater’“At a temple site in the Republic of Georgia, letters carved in stone could change the way we see the development of writing.”

bonus: Microbiologists Keep Finding Giant Viruses in Melting Permafrost

bonus bonus: Ancient Cats Drove Ancient Dogs to Extinction – woof? (O.O)

bonus bonus bonus: this year’s ig nobel mathematics prize went to the authors of The Case of Moulay Ismael – Fact or Fancy?“Textbooks on evolutionary psychology and biology cite the case of the Sharifian Emperor of Morocco, Moulay Ismael the Bloodthirsty (1672–1727) who was supposed to have sired 888 children. This example for male reproduction has been challenged and led to a still unresolved discussion. The scientific debate is shaped by assumptions about reproductive constraints which cannot be tested directly — and the figures used are sometimes arbitrary. Therefore we developed a computer simulation which tests how many copulations per day were necessary to reach the reported reproductive outcome…. The results indicate that Moulay Ismael could have achieved this high reproductive success. A comparison of the three conception models highlights the necessity to consider female sexual habits when assessing fertility across the cycle. We also show that the harem size needed is far smaller than the reported numbers.” (~_^)

and the tweet of the week!:


(note: comments do not require an email. moulay ismael the bloodthirsty!)

(…also, i think that’s some really bad french! (*^_^*) )

seriously, tho. this is not me returning to blogging. sorry! i think i need another week or so of r&r.

but, i have been binge watching a lot of netflix shows/youtube videos, and i thought i’d share one with you: a bbc horizon documentary from 2011 — Are We Still Evolving? — hosted by one dr. alice roberts.

for the first ten or fifteen minutes, you might feel like poking out your eyeballs, but the show does get better and quite adequately explains rapid evolution, recent human evolution, and even — *gasp* — human biodiversity, albeit only such “nonthreatening” aspects of hbd like lactase persistence and high-altitude adaptations. still, it’s pretty cool that the show goes there at all.

of course roberts gives behavioral genetics a wiiiiiide berth. in fact she doesn’t even mention biological/genetic explanations for behavioral traits at all — until near to the end when she talks to the very frank dr. jeffrey steinberg about genetic engineering and intelligence briefly comes up. oops!

pay close attention to what stephen stearns has to say at ca. 47:45:

“Well I think what is very probably going on is that selection is moving a population up and down all the time. It goes off in a certain direction for a while, and then it goes back in the other direction. It’s only if you get a significant change in the environment that it will then continuously go in a new direction.”

in other words, the average frequencies of genes in populations matter, and those frequencies can vary over time depending up the selection pressures.

k. that’s all i’ve got for you. back to my la-z-boy. enjoy! (^_^) :

(note: comments do not require an email. this is not the pipe you’re looking for.)

there’s some amount of confusion out there in the hbd-o-sphere (and beyond!) about inclusive fitness, which is understandable since the concept is not that straightforward — especially for those of us who are not scientists. i thought it’d try to dispel some of that misunderstanding by sharing my layman’s understanding of the concept — i think i grok the idea pretty well now (in a basic sorta way) — hope i don’t add to the confusion!

to start with, inclusive fitness is NOT some sort of biological law that organisms (including humans) will automatically be altruistic towards other individuals with whom they share a lot of genes (or vice versa if vice versa). if you hold that idea — and i get the impression that a lot of people do — get it out of your mind right now! you’ll feel better for it, trust me.

inclusive fitness is simply a concept or model which explains HOW certain social behaviors — especially altruism — might’ve evolved at all. period. full stop.

to understand inclusive fitness, we need to back up a sec first and think about fitness and what that is. very (very!) simply, fitness refers to an organism’s ability to survive and reproduce in a particular environment. traits — including behaviors — that enable an organism to survive and successfully reproduce will be selected for simply because that organism *is* able to survive and reproduce in its environment. this is natural selection. pretty simple, really, darwin’s dangerous idea.

when it comes to certain social behaviors in humans, it’s readily understandable why many of them were selected for. for example, mothers who devote a lot of time and energy to care for their infants — who obviously can’t take care of themselves and would die without any care — will be more fit than those mothers who don’t. the genes that predispose for those behaviors get selected for since children get half of their dna from their mothers, and the ones that are cared for are much more likely to survive.

what was — and to some extent still is — a big mystery is why other sorts of altruistic behaviors were ever selected for even though they hurt an organism’s fitness. how would self-sacrificing altruistic behaviors directed towards non-descendants ever be selected for? for instance, why on earth would somebody feel compelled to run into a burning building to save a neighbor (who wasn’t their child) at great risk to their survival and, therefore, to their fitness? we can see how “genes for altruistic behaviors towards offspring” could be passed down from mother (or parents) to kids, but how were genes for more general altruistic behaviors selected for?

here is where william hamilton‘s absolutely genius idea — inclusive fitness — comes in: perhaps certain social behaviors, which on the surface appear to reduce an organism’s fitness, and so shouldn’t get selected, might’ve been selected for if those behaviors were directed toward other close kin with whom individuals also share much dna in common.

everybody gets half of their dna from each of their two (for now, anyway) parents. but we also share dna with siblings and (blood-related) aunts and uncles and (wait for it…) cousins. given this inheritance pattern, probability says, for instance, that, in a randomly mating population, an individual should share 12.5% of their dna with a first cousin. so, if an individual with certain “genes for altruism” behaves altruistically toward their first cousins, odds are not bad that those first cousins might also have those same “genes for altruism.” here, then, we have a mechanism for how apparently self-sacrificing social behaviors can be selected for: since the altruistic individual 1) aids close kin with whom he shares much of his dna AND 2) probably in many instances shares the same “genes for altruism,” his being altruistic toward those kin 1) does not reduce his fitness AND 2) the “genes for altruism” get selected for, too. mystery solved. (see also: kin selection.)

one way i like to think of inclusive fitness — which, perhaps, isn’t entirely the right way to look at it, but i feel it helps my understanding — is that if you wanted to calculate an individual’s total fitness by adding up how many actual copies of his genes he passed on, you need to add together those found in his offspring and those in his close relatives’ offspring. in other words, you need to add together his own direct fitness plus his close relatives’ fitness to get his inclusive fitness (or his total fitness).

it seems likely that many of the altruistic (or spiteful, etc.) behaviors we’re talking about are pretty general in nature, i.e. not that specific behaviors like “be altruistic to your close kin” were selected for, but rather more like “be altruistic to the people around you, because they’re probably your close kin” were. it remains to be seen how much kin recognition plays a role in altruism in humans, but that’s a topic for another post anyway. for right now, i just wanted to make clear what inclusive fitness is — and isn’t. again, inclusive fitness is a concept which explains HOW altruistic behaviors MIGHT be selected for. it does NOT predict that individuals will DEFINITELY be more altruistic toward those with whom they share much dna.

the whole topic of inclusive fitness is, of course, much more complicated than all that, but i think this is a good basic intro to the concept. hope so, anyway! (^_^)

(note: comments do not require an email. citizens against altruism!)

there were a handful of science news stories out this past week about how a couple of researchers reportedly discovered a case of “group selection” in certain spiders (Anelosimus studiosus or tangle web spiders): for example, see Proving ‘group selection’: Spider colonies need the correct mix of personalities to survive and Elusive Form of Evolution Seen in Spiders. a bunch of people on twitter got all excited about this finding, because they wonder if (some of them i think hope that) group selection might also apply to groups of humans. i agree: that would be very interesting to know one way or the other. so i went and read the original paper — Site-specific group selection drives locally adapted group compositions — to see what these guys had found.

before i offer up my admittedly layman’s thoughts on this paper, let me first say what a really neat piece of research this was! if there existed a nobel prize for geeky dedication and sheer nerdiness, these guys would’ve won it! — and i mean that as a compliment! the researchers, pruitt and goodnight, studied groups of tangle web spiders in the wild, captured some and brought them back to their lab, conducted personality tests on the spiders (yes! there are apparently personality tests for spiders!), painstakingly painted those little dots on the backs of individuals to keep track of them (you know, like how they sometimes do with bees), bred the spiders, released new groups of them back into the wild, and checked up on them one and two generations later to see how they fared. this is some really cool research! nerds ftw! (^_^)

but did they find evidence for group selection?

weeeellll, no, i don’t think so.

to begin with, right at the start of the paper pruitt and goodnight (p&g) define group selection as “selection caused by the differential extinction or proliferation of groups.” eeeehhhh, as far as i understand it, that’s not really the definition of group selection, and even the authors admit that their definition is a “broad” one.

group selection is more accurately defined as when “natural selection [operates] between groups of organisms, rather than between individuals.” in contrast, p&g’s broad definition could theoretically include cases in which natural selection worked between individuals (individual selection) which also just incidentally happened to result in the proliferation of the group to which the lucky selected individuals belonged. an example of this is the selection for lactase persistence in some humans in which those individuals who could drink milk as adults were able to leave behind more descendants than those individuals who could not. while lactase persistence might indeed have benefitted groups of milk-drinking individuals, natural selection did not act on the group, but rather on the individuals in that group. (pretty sure i stole this example from @supermisdreavus, but i can’t find where he said that right now.)

in other words, you always need to work out what the target of selection is: the group or the individuals that make up the group. (really it’s ultimately the genes, but — oh, nevermind.) remember that “‘a fleet herd of deer’ is really just a herd of fleet deer.”

so, really, the discussion could end right here, because i don’t think the authors are talking about group selection proper. but, since i’ve read the whole paper, i’ll carry on. (yes, i’m one of those people who’s never learned to quit while they’re ahead!)

a. studiosus spiders live either as solitary individuals or in groups where they cooperate on tasks like hunting and the raising of young. the individuals that live together in groups are, on average, more closely related to one another than those that live alone [pdf] — they’re generally as related to one another as though they were half-siblings. one reason why they’re probably not more related to one another in these groups — like to the degree that ants or bees in colonies often are — is that the males move between groups. remember that.

the personality types of the individual spiders in a. studiosus groups come in two sorts: docile and aggressive. the docile spiders are typically pretty laid back and aren’t much bothered by the presence of other spiders (even spiders from other species), whereas the aggressive individuals like their space — they’ll chase off other individuals. individuals of both types are found in groups of a. studiosus, but the frequencies vary. from the paper:

“At…high-resource sites, small colonies were dominated by docile females and the frequency of aggressive individuals increased with colony size. By contrast, at low-resources sites, small colonies were dominated by the aggressive phenotype and the frequency of the docile phenotype increased with colony size.”

well, that doesn’t sound too surprising at all. in locales where there is plenty of resources, there are more laid back individuals in the colonies, prolly ’cause being laid back works just fine. in areas where resources are lacking, more aggressive individuals do better. btw, they found that the heritability of these personality types in the spiders is 0.66.

groups that have more docile individuals (i.e. the ones in high-resource areas) are at a greater risk of invasion by other types of spiders which, over the long-term, tends to be a really bad thing for an a. studiosus colony (i.e. it’s usually destroyed). groups that have more aggressive individuals (i.e. the ones in low-resource areas) tend in bad times to experience too much “egg case cannibalism.” needless to say, that’s not a good thing over the long-term either.

what p&g did in their study was to introduce into the wild — into differing environments — groups having varying frequencies of these personality types [source]:

“He [pruitt] took spiders from warrior-heavy colonies and used them to assemble new groups that were heavy on the nannies. He also used spiders from mostly docile colonies to create warrior-laden groups. In addition, he assembled control groups that matched the composition of their original groups.”

what they found was that after three generations:

“60 percent of the colonies were extinct. Control groups that returned to their ancestral homes tended to do well, and those that were transplanted into a new environment generally died. Neither of these outcomes was much of a surprise.

The most interesting results came from colonies made up of spiders that had been forced into a composition different from the one they grew up in — warrior-majority colonies containing spiders from mostly docile groups, for example. The colonies whose composition fit the new environment tended to survive. But over time, surviving colonies reverted to their members’ original group composition. The warrior-majority colonies went back to having more nannies, for example. On the face of it, this is bizarre behavior; if the colonies are well-suited to their environment, why not maintain that ratio? It seems that some innate sense, perhaps encoded in the spiders’ genes, pulled the colony back to its original configuration, even though this change meant the colony would perish.”

well, i dunno. is that really “bizarre behavior?” i mean, if the personality types of a. studiosus are really highly heritable (0.66), is it strange that a population having come from a bunch of docile individuals should regress toward a docile mean? and vice versa? don’t forget, too, that the individuals in these groups are all related to one another as though they were half-siblings, so presumably individuals of either personality type might carry a great many genes of the other type in their genomes. (don’t know about that — i’m just guessing here, tbh.)

what really made me question whether or not this is “bizarre behavior” is the way in which the researchers bred the spiders when they had them in captivity [from the methods section at the end of the paper]:

“Females were mated randomly to a male of like behaviour type from their same source population, but which was collected from a source colony >5m distance.”

hmmmm. i dunno about that. they mated all the females with males of the same personality types, docile or aggressive? i’m guessing that they did this in order to reduce the number of possible confounding factors in the study, but i’m afraid they might’ve added something to the mix here that wouldn’t be found in nature, i.e. a 100% assortative mating rate (for personality type). mightn’t this almost guarantee that individual spider lineages would regress to their original personality-type means? docile females always mated with docile males and aggressive females always mated with aggressive males? that seems unlikely to happen in nature, especially given the fact that the males normally leave their colonies and move to others. (btw, male a. studiosus spiders prefer moving into colonies over mating with lone females. typical males, favoring harems! (~_^) )

p&g offer a number of explanations for how the frequencies of personalities in the groups might change over time:

“How native spiders are actually able to adjust their composition is unknown, but plausible regulatory mechanisms include developmental plasticity in the docile:aggressive phenotypes, policing of group membership, phenotype-biased dispersal, and/or selective cessation of reproduction.”

they reject the first explanation (the plasticity one) on the basis (in part) of the rather high heritability of spider personality types which they found. i’m inclined to agree with them on that.

out of their other reasons, policing of group membership and selective cessation of reproduction are behaviors that can be easily explained by natural selection between individuals, especially in populations that have rather highly related individuals so that levels of altruism are pretty high. the selective cessation of reproduction occurs, for instance, in some ant colonies since, due to the really high degrees of relatedness between individuals, the inclusive fitness payoffs are really large (eg. if you share three-quarters of your dna with your sister’s offspring, there’ll be a greater genetic payoff in helping her to reproduce rather than reproducing yourself, since you’d only share half of your genome with your offspring). that’s individual selection, not group selection. h*ck! both behaviors also occur in meerkat groups, although they, of course, show much less specialization of individuals than ants or bees. the policing of group membership can also be plausibly explained by natural selection between individuals — for example, aggressive individuals keep at bay all sorts individuals because that’s good for aggressive individuals (who are typically found in sparse environments).

so, i’m not at all convinced that pruitt and goodnight have found an example of group selection. i think they’ve found that genetics (as indicated by the heritability of the spiders’ personality traits) and natural selection certainly shape the average characteristics of groups, but it looks to me as though the seemingly “bizarre behaviors” that they found can easily be explained by individual selection. in fact, i’m more than a little concerned that due to the way they bred the spiders, p&g may have affected the outcomes of the reintroduced groups.

see also: The False Allure of Group Selection from steven pinker.

(note: comments do not require an email. a. studiosus group web!)

we know that human biodiversity (hbd) is true because, for one thing, we have many, many examples of it (see here)!

additionally, both the workings of the natural world and specifically the theory of evolution predict that hbd must be the case.

nature likes to throw up variety (see here for example) — the variation between individual organisms is, after all, what natural selection acts upon — and there’s no reason for humans to be any exception. add to that the fact that humans reproduce sexually — with all the genetic shuffling and remixing that happens there — and it’s inevitable that individual humans will be biologically diverse.

various groups or populations of humans — ranging from small-sized families to races and even beyond (for example, think: east asians+native americans together compared to caucasians or subsaharan africans) — will also inevitably be biologically diverse from one another, to greater or lesser degrees, due to forces of evolution such as natural selection, gene flow, and/or genetic drift.

keep in mind that humans — including various discrete-ish human populations (biological borders are fuzzy, naturally) — have experienced recent evolution (i.e. within the last 40,000 years or so), that human evolution has probably sped up since the advent of agriculture, and that we are undoubtedly still evolving today.

ignoring or denying the existence of human biodiversity won’t make it go away. hbd — and its implications — will remain a reality in spite of all your hopes and dreams, however well-intentioned they may be.

this is one of a set of posts on What is Human Biodiversity? please, before you fire off a rant leave a comment here, check out the other posts, because your question or objection may have been dealt with in one of them. here they all are!:

what is human biodiversity (hbd)?
what human biodiversity (hbd) is not
examples of human biodiversity (hbd)
hbd and racism
hbd and politics

(note: comments do not require an email. another great moment in evolution.)

jean-baptiste lamarck was (mostly) wrong when he suggested that evolution happened via a form of “soft inheritance”, i.e. that organisms passed on traits which they had acquired during their lifetimes to their offspring (see: lamarckism). as alfred russel wallace explanied in 1858, evolution happens instead via natural selection (and, of course, other evolutionary forces like genetic drift, etc.) [pg. 60]:

“Neither did the giraffe acquire its long neck by desiring to reach the foliage of the more lofty shrubs, and constantly stretching its neck for the purpose, but because any varieties which occurred among its antitypes with a longer neck than usual *at once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the first scarcity of food were thereby enabled to outlive them.*”

nowadays everyone giggles at lamarckism, but i always want to come to lamarck’s defense, though, when people talk disparagingly about him and his ideas because 1) no one knew how evolution worked in the eighteenth century, not just lamarck, and he was only trying to come up with a naturalistic explanation for all the variation we see in life on earth for goodness sake, and 2) i happen to know that some other scientists didn’t like his ideas and actively worked to have his ideas suppressed. or ignored, anyway. quite successfully, too, i’m sorry to report. here from “Lamarck, Evolution, and the Politics of Science” [pgs. 291-293, 296 – pdf – link added by me]:

“With the exception of a few brief and scattered comments Lamarck’s evolutionary ideas were publicly received in silence. Attention will be paid here to the posture toward Lamarck’s ideas adopted by the dominant figure of French natural science at the time: Georges Cuvier.

“Georges Cuvier’s magisterial and disapproving presence has long been recognized as a factor in the poor reception of Lamarck’s evolutionary theory by his contemporaries. Cuvier’s reasons for opposing the hypothesis of species mutability have been dealt with a length elsewhere and do not need to be repeated here. Primary concern here will be with the way in which he treated Lamarck’s views.

“It is not likely that Lamarck’s physico-chemical views were neglected for reasons of jealousy, as Lamarck had assumed, and the same can be said of the treatment of his evolutionary views. This does not mean, however, that these views were not *methodically* neglected. Consider the following statement written by Cuvier in 1806, setting forth his view of what scientific bodies had to do to assure for the science of geology the growth of which that science was capable:

“‘[Scientific bodies] must maintain in [geology’s] regard the conduct that they have maintain since their establishment in regard to all the other sciences: To encourage with their eulogies those who report positive facts, and to retain an absolute silence over the systems which succeed to one another.’

“One may well presume that the ‘absolute silence’ recommended for ‘systems’ was the very antidote that had first been applied to Lamarck’s chemical theories and was later applied to his zoological theories. To Cuvier, evidently, Lamarck’s chemical and zoological theories *both* appeared as ‘vast edifices [constructed] on imaginery bases,’ and thus both deserved the same treatment. In his ‘Eloge’ of Lamarck Cuvier wrote:

“‘…whatever interest [Lamarck’s zoological works] may have exicited by their positive parts, no one believed their systematic part dangerous enough to merit being attacked; it was left in the same peace as the chemical theory.’

“One may suppose that Cuvier’s use of the words ‘dangerous enough to merit being attacked’ instead of some equivalent of ‘reasonable enough to merit being considered’ is not without significance. One may also remark that, in the statement that Lamarck’s zoological speculations [!! -h.chick] were ‘left in the same peace as the chemical theory,’ the word ‘peace’ should probably be interpreted strictly as the *public* silence that Cuvier recommended for all ‘systems.’ Certainly the picture that Etienne Geoffroy Saint-Hilaire painted of the last years of Lamarck’s life was not one of peaceful neglect. In Geoffroy’s words, ‘attacked on all sides, insulted even by odious jests, submitted to the insult from them with a sorrowful patience….’

“In an unpublished manuscript one finds Cuvier writing about Lamarck: ‘In truth his explanations are sometimes very amusing despite the admiration that some naturalists pretend to show for them.’ In another work, published posthumously, Cuvier’s comment on authors who had favored the idea of species transformation was: ‘From the moment that these authors wished to enter into detail they fell into ridicule.’ Frederic Cuvier said of his brother Georges that he put ideas of species transformation

“‘…in the rank of those frivolous games of the imagination with which the truth has nothing in common; with which one may amuse oneself when they are skillfully and gracefully presented, but which lose all their charm when taken seriously….’

“It is difficult to estimate just how much the posture of Cuvier toward Lamarck’s evolutionary ideas may have influenced contemporaries who might otherwise have been disposed to give Lamarck’s ideas some serious attention. Presumably Cuvier’s influence in this regard was considerable. The combination of public neglect and private ridicule seems to have been devastating for Lamarck’s evolutionary theory.”

cuvier, for various reasons, simply did not like the idea of the “transmutation of species” and, rather than address lamarck’s ideas directly, he opted for ignoring them — and used his position as a leader in the sciences to encourage other scientists to do the same. bad form.

darwin, too, was concerned about how fellow scientists would treat him if and when he published his ideas on evolution. it took him twenty years to publish his theories, and you often hear about how he delayed publication because he didn’t want to offend his religious wife (or maybe it just took twenty years for him to do the research and writing up), but there was definitely a lot of opposition to the idea of the transmutation of species in the sciences in england during darwin’s day and natural theology still held sway. from Evolution: The Remarkable History of a Scientific Theory:

“Darwin conceived his theory in 1838, but he did not publish anything about it for twenty years. Recognizing the depth of opposition among scientists to the transmutation hypothesis, he spent much of this time endeavoring to anticipate and answer in advance objections to his theory. In the process, he perfected his thinking on the gradual divergence of varieties into distinct species through competition, marshaled evidence for evolution from comparative anatomy and embryology, fitted fossils into evolutionary series and distribution patterns, and tried to imagine intermediate stages in the development of the eye and other complex organs….

“The transmutation hypothesis was widely debated but little accepted among European naturalists during the early nineteenth century. It had a revolutionary taint.”

ah. politics. even scientists are only human.

more on the politics of the day in darwin’s time from Evolution: The History of an Idea [pg. 97, pgs. 126-27, pg. 134 – my emphasis]:

“Materialism was an integral aspect of a revolutionary ideology that wanted to sweep all traces of the old social hierarchy aside. Natural theology and idealism were invoked by conservatives who wanted to preserve their position in that hierarchy: the world was designed by a God who intended us all to accept our place in the preordained social scale. The situation was complicated, however, by a growing middle class making fortunes out of the new mechanized industries. They too wanted a social hierarchy that would include them in the ruling class. But they did not want a revolution that might sweep away the ownership of property. The middle class wanted reforms that would eliminate old restrictions on the individual’s right to trade freely and that would allow them access to political power. Many of the scientific theories developed in the nineteenth century can be related to the desires of those engaged in these broad social movements to legitimize their preferred model of society by claiming that it was ‘only natural.’

“Beginning in Britain, the industrial revolution was transforming the social and economic map of Europe. America too was beginning to flex its muscles as a world power. The idea of progress, first articulated by Condorcet and other Englightenment thinkers, now became the dominant model of social change. A parallel idea could also be applied to the natural world. Paleontologists uncovered a fossil sequence from simple to complex animals that even conservatives could not ignore. Liberals and radicals welcomed the idea because progress in the natural world seemd to hint that progress in the social world was inevitable….

“Evolutionism became part of the radical campaign to discredit the old worldview which propped up aristocratic privilege. The claim that God had designed a hierarchical universe in which everyone should keep to their allotted place was used to bolster the position of the upper classes. Both the radicals and the less strident middle-class activists saw a universe which changed through time as evidence that human conventions such as the class system could be changed….

“Darwin’s reluctance to publish his own theory must be understood in the context of the reputation acquired by transmutationism during the era of radical scientists such as R.E. Grant. Endorsement by radical scientists allowed the theory to be branded as dangerous materialism, subversive of the moral as well as the intellectual order.

hmmmm. sound familiar?

the political orthodoxy of today — especially in the sciences — as we all know is political correctness. now, for some strange reason that i have never been able to figure out, the perfectly reasonable idea (which i fully support) that everyone in our society ought to be treated equally has become confused with and all bound up in the completely crazy idea that everyone in our society is actually equal or the same. (i often wonder about the mentality of politically correct people — do they need to believe that all people are the same in order to be able to treat everyone equally? i don’t know, but that would certainly be interesting if it were the case.) so now, not only has it been made difficult if not impossible even to discuss known or possible biological differences between the sexes or ethnic groups or races, sexes and ethnic groups and races no longer exist! (almost.) and as henry harpending has pointed out, the parallel (resultant!) trend in population genetics has been “neutralism” — i.e. that natural selection has not led to any important differences between any human populations. so for nicholas wade to write a book like A Troublesome Inheritance — well, that was just a big no-no. as we all knew it would be.

i’m not a scientist. i don’t even play one on the internet. but i’ve had a lifelong interest in science, i’ve tried to keep up-to-date with the latest in scientific findings (as much as a layperson can do) — especially biology — for many years now, and i actually did take some science classes (including higher-level ones) in college, so i’m not entirely ignorant of how science works. and as far as i can see, speculation is a part of science. it must be. it’s the first step! speculation about the world is the brainstorming part of science — when hypotheses are built — it’s theory-building (theory with a small “t”). but, of course, speculating is just the start of scientific investigation — all the real investigative sciencey stuff has to follow it, of course. but there is definitely a place — a need! — in science for speculation — as darwin said.

and when some scientists try to squash the speculations of others…or even create an atmosphere in which people feel uncomfortable voicing their ideas…well, that’s just scientists behaving badly. not to mention unscientifically.

see also: Letters: ‘A Troublesome Inheritance’ and Geneticists Denounce Nicholas Wade’s “Speculative” Chapters as “Speculation” from steve sailer and At Least Erroneous in Faith from henry harpending and and Darwin on the Need for Speculation in Science from steve sailer

(note: comments do not require an email. lamarck.)

DNA USA*“[A]bout about 4 percent of whites have at least 1 percent or more African ancestry. Although it is a relatively small percentage, the percentage indicates that an individual with at least 1 percent African ancestry had an African ancestor within the last six generations, or in the last 200 years. This data also suggests that individuals with mixed parentage at some point were absorbed into the white population. Looking a little more deeply into the data, Kasia also found that the percentage of whites with hidden African ancestry differed significantly from state-to-state. Southern states with the highest African American populations, tended to have the highest percentages of hidden African ancestry…. Previous published studies estimate that on average African Americans had about 82 percent African ancestry and about 18 percent European ancestry. But in self-identified African Americans in 23andMe’s database, Kasia found the average amount of African ancestry was closer to 73 percent. Kasia found significant differences in state-to-state comparisons. African Americans in the northern and western states have more mixed ancestry than those in the southern states…. On average Latinos had about 70 percent European ancestry, 14 percent Native American ancestry and 6 percent African ancestry. The remaining ancestry is difficult to assign because the DNA is either shared by a number of different populations around the world, or because it’s from understudied populations, such as Native Americans.” – from 23andMe.

Common Variants in the CDH7 Gene are Associated with Major Depressive Disorder in the Han Chinese Population“Recent genome-wide association study also demonstrated that CDH7 was significant associated with bipolar disorder…. Our results support CDH7 to be a risk factor of MDD in the Han Chinese population. However, further studies with more markers and independent samples were suggested to validate our findings.”

Humans May Have Been Stuck on Bering Strait for 10,000 Years“In the new Perspectives article, published today (Feb. 27) in the journal Science, the researchers compile existing data to support the idea, known as the Beringia standstill hypothesis. Among that evidence is genetic data showing that founding populations of Native Americans diverged from their Asian ancestors more than 25,000 years ago. In addition, land in the region of the Bering Strait teemed with grasses to support big game (for food) and woody shrubs to burn in the cold climate, supporting a hard-scrabble existence for ancient people.” – razib is skeptical.

Was skin cancer a selective force for black pigmentation in early hominin evolution?“[D]ata on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.”

Neanderthal Introgression at Chromosome 3p21.31 Was Under Positive Natural Selection in East Asians“Studies of the Neanderthal and Denisovan genomes demonstrate archaic hominin introgression in Eurasians. Here, we present evidence of Neanderthal introgression within the chromosome 3p21.31 region, occurring with a high frequency in East Asians (ranging from 49.4% to 66.5%) and at a low frequency in Europeans. We also detected a signal of strong positive selection in this region only in East Asians…. [S]uggestive evidence supports latitude-dependent selection, implicating a role of ultraviolet-B.”

Neanderthals challenge the origins of speech“Neanderthals, may well have spoken in languages not dissimilar to the ones we use today…. [I]n terms of mechanical behaviour, the Neanderthal hyoid was basically indistinguishable from our own, strongly suggesting that this key part of the vocal tract was used in the same way. ‘From this research, we can conclude that it’s likely that the origins of speech and language are far, far older than once thought.'” – h/t billare (who is 0.1% neanderthal)!

READ THIS (yes, there *will* be a pop quiz on the material later in the week (~_^) )!: Environmental Hereditarianism“[T]here is little evidence linking most ‘measurable’ aspects of the environment to human physical or behavioral traits…. Most of the solid evidence we do have for environmental impacts come in the forms of things that do physical damage (e.g., maiming limbs or traumatic brain injury) – a category which includes poisons; or are developmental deficits, such as malnutrition. Much of the rest of it (take your pick) is lacking.” – from jayman. – previously: it’s not nature and nurture….

Outliers – from greg cochran.

New evidence confirms link between IQ, brain cortex“Rate of change in the thickness of the brain’s cortex is an important factor associated with a person’s change in IQ, according to a collaborative study by scientists in five countries…. This study is the first to show the association between cortical thickness and development in full scale IQ, and has potentially wide-ranging implications for the pedagogical world and for judicial cases in which the defendant’s IQ score could play a role in determining the severity of the sentence.”

The Germ Theory of Democracy, Dictatorship, and All Your Most Cherished Beliefs“What kind of government do you live under? Who are your sexual partners? How do you treat strangers? All of these questions may mask a more fundamental one: What germs are you warding off?” – h/t jason collins! – but see this previous post: pathogens and consanguinity“the BIG outliers, though, are the arabs and all their middle eastern/north african/south asian muslim buddies. they are the ones throwing off the correlation completely…. these societies are amongst those that have the highest consanguinity rates, and yet some of their pathogen index scores are *very* low.” that part of the world also does not do well when it comes to (liberal) democracy. – see also jayman’s response.

Nicholas Wade Takes on the Regime – jared taylor reviews nicholas wade’s upcoming book on race. – h/t hbd bibliography! – see also this comment from jayman. – and see also Harmful, toxic equalism from the awesome epigone.

The Nature of Race – from karl boetel and john furest. see also here.

12,000 year old prehistoric art shows woman hunting – maybe. kinda/sorta. (not really.) – from adam benton.

Altruism and the Dark Side of Agreeableness“[B]eware of really nice people. If they seem too good to be true, they usually are.” – from staffan.

Forgotten fathers: paternal influences on mammalian sex allocation“A growing body of evidence suggests that the assumption that males produce an unbiased proportion of X- and Y-chromosome-bearing spermatozoa is not always valid with significant between- and even within-individual variation.” – a mechanism for trivers-willard? – h/t lars penke!

Digit Span: the modest little bombshell and What does IQ 70 mean for black and white kids? – from dr. thompson.

The paradox of the Visual Word Form Area“The VWFA functions differently in different human populations. The difference is striking between people who use alphabetical script, where each symbol represents a sound, and those who use logographic script, where each symbol represents an idea. Chinese subjects process their idea-based symbols with assistance from other brain regions, whereas Westerners process their sound-based symbols only in the VWFA.” – from peter frost.

The man who destroyed America’s ego“How a rebel psychologist challenged one of the 20th century’s biggest—and most dangerous—ideas…. Among the most egregious errors they discovered were those in the papers that focused on academic performance. A correlation had been repeatedly found between high self-esteem and good grades. So, the logic went, if you boosted self-esteem you’d also boost grades. But the authors had made one of the most elementary mistakes in science. ‘When they tracked people over time,’ says Baumeister, ‘the grades came first, and then the self-esteem. High self-esteem was a *result* of good grades, not a cause.'” – h/t matthew wygant!

Genetic Influences on Political Ideologies: Twin Analyses of 19 Measures of Political Ideologies from Five Democracies and Genome-Wide Findings from Three Populations“Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled…. We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one’s genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.”

Why Americans Are So Polarized: Education and Evolution“Improvements in learning — which correlates with stronger partisanship — and the tendency to choose likeminded mates may be helping to create divided politics.” – from avi tuschman. – h/t eddy elmer!

Conservatives generally more willing to take business risks, study finds

Paternal Age at Childbearing and Offspring Psychiatric and Academic Morbidity“In the study population, advancing paternal age was associated with increased risk of some psychiatric disorders (eg, autism, psychosis, and bipolar disorders) but decreased risk of the other indexes of morbidity.”

A Genotype-First Approach to Defining the Subtypes of a Complex Disease – h/t kevin mitchell who tweeted: “Increasing recog’n that ‘common disorders; like autism really umbrella terms for many rare diseases.”

Researchers look at boy-girl differences in autism“Boys, it seems, can develop autism from a relatively small genetic hit, according to a study published today in the American Journal of Human Genetics. It takes more of a genetic wallop, though, to cause autism in girls – so when they do get it, they’re worse off. The same explanation holds true, researchers think, for the gender imbalance in ADHD (attention-deficit hyperactivity disorder), intellectual disabilities and schizophrenia.” – see also: A Higher Mutational Burden in Females Supports a “Female Protective Model” in Neurodevelopmental Disorders.

China Cracks Down on DNA Testing – h/t jayman!

Epigenetics: The sins of the father – big story in nature today. – “The roots of inheritance may extend beyond the genome, but the mechanisms remain a puzzle.” – but swedish scientist on twitter says: “But Rando misquotes Swedish human data in his Cell paper on mice. Caution for epigenetic hype!” – hmmmm. =/

The Consequences of Natural Morality“Good and Evil are not objective things. They exist as subjective impressions, creating a powerful illusion that they are objective things. This illusion that Good and Evil are objects independent of the conscious minds that imagine them exists for a good reason. It ‘works.’ In other words, its existence has enhanced the probability that the genes responsible for its existence will survive and reproduce.” – from helian.

Digit ratio predicts eminence of Polish actors – this one’s for sisyphean! (^_^) – h/t ben southwood!

Sex differences in color preferences transcend extreme differences in culture and ecology.

In Academia, Women Collaborate Less With Their Same-Sex Juniors“‘Some older women treated us younger women almost worse than some men did,’ she says. ‘We called it the “Queen Bee syndrome.”‘” – heh. – h/t claire lehmann!

Women Can Keep the Vote: No Evidence That Hormonal Changes During the Menstrual Cycle Impact Political and Religious Beliefs – behind paywall.

Women ‘subconsciously outdo other females’ during ovulation“But what the researchers found really surprising is that ovulating women did not appear to want a higher standing over men – they became kinder to them. When playing the dictator game, non-ovulating women shared 45% of their money with men, while ovulating women were willing to share 60% of their money with men. These findings are unlike anything we have ever seen in the dictator game. You just don’t see people giving away more than half of their money,’ says Prof. Durante.” – (~_^)

Women Outperform Men in Ultra-Distance Swimming – The ‘Manhattan Island Marathon Swim’ From 1983 to 2013. – because we float better (because we have that extra layer of fat)? (~_^)

Sameness and the self: philosophical and psychological considerations.“[H]ow can a person maintain a belief in the sameness of self over time in the face of continual psychological and physical change?” – h/t neuroskeptic!

Young Children Can Be Taught Basic Natural Selection Using a Picture-Storybook Intervention – but not politically correct people, apparently. (~_^) – h/t stuart ritchie!

Study: Racial bias in pain perception appears among children as young as 7 – see also: Psychologists use baby-cam to study infants’ exposure to faces.

Mixed-race children ‘are being failed’ in treatment of mental health problems“Children of mixed race are at greater risk of suffering from mental health problems and are not getting the support they need, says a report.” – in the u.k.

Inferring Character From Faces: A Developmental Study.“This research suggests that the predisposition to judge others using scant facial information appears in adultlike forms early in childhood and does not require prolonged social experience.”

Los europeos no inventaron la desigualdad en Hispanoamérica – from eduardo zugasti.

Native American city on the Mississippi was America’s first ‘melting pot’carcosa cahokia. – “By analyzing the teeth of those buried in different locations in Cahokia, Emerson, state archaeological survey bioarchaeologist Kristin Hedman and graduate student Philip Slater discovered that immigrants formed one-third of the population of the city throughout its history (from about AD 1050 through the early 1300s).”

Two-hundred-year drought doomed Indus Valley Civilization“Monsoon hiatus that began 4,200 years ago parallels dry spell that led civilizations to collapse in other regions.”

HBD 101 – from malcolm pollack. (*^_^*)

bonus: A ‘Second Great Wave’ of immigration?“‘Once again, the country is approaching a percentage of foreign-born not seen since the late 1800s and early 1900s,’ the Census Bureau wrote on its blog this week.” – =/ – h/t ray sawhill!

bonus bonus: Muhammad’s birthplace to be razed – remember that the najdis hate the hejazis and vice versa.

bonus bonus bonus: Giant Virus, Awakened From 30,000-Year Slumber, Is Still Infectious – ruh roh (if you’re an amoeba)!

bonus bonus bonus bonus: Crawling Through The Brain Without Getting Lost“Do the wasps taste their way through a cockroach brain?” – mmmmmm! =/

bonus bonus bonus bonus bonus: Australia: Snake eats crocodile after battle – WITH PICTURES! =o – h/t ed west!

(note: comments do not require an email. g-8 selfie. (~_^) )


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