linkfest – 01/18/15

Ancient Jomon people not like present-day East Asians“‘We found a unique genetic position of the Jomon people who had diverged before the diversification of most of present-day East Eurasian populations including East Eurasian Islanders. This indicates that Jomon people were a basal population in East Eurasia and genetically isolated from other East Eurasians for long time.'” – h/t charles!

Uncovering the Genetic History of the Present-Day Greenlandic Population“[W]e analyzed ∼200,000 SNPs from more than 10% of the adult Greenlandic population (n = 4,674). We found that recent gene flow from Europe has had a substantial impact on the population: more than 80% of the Greenlanders have some European ancestry (on average ∼25% of their genome). However, we also found that the amount of recent European gene flow varies across Greenland and is far smaller in the more historically isolated areas in the north and east and in the small villages in the south. Furthermore, we found that there is substantial population structure in the Inuit genetic component of the Greenlanders and that individuals from the east, west, and north can be distinguished from each other. Moreover, the genetic differences in the Inuit ancestry are consistent with a single colonization wave of the island from north to west to south to east. Although it has been speculated that there has been historical admixture between the Norse Vikings who lived in Greenland for a limited period ∼600–1,000 years ago and the Inuit, we found no evidence supporting this hypothesis. Similarly, we found no evidence supporting a previously hypothesized admixture event between the Inuit in East Greenland and the Dorset people, who lived in Greenland before the Inuit.” – h/t razib!

Y chromosome super-fathers“Most of these lineages are so young that there are good chances that their founders were figures from history or mythology.” – from dienekes.

Bone Tool Discovered at Neanderthal Site in France“A bone tool from the Grotte du Bison at Arcy-sur-Cure in France is further evidence that Neanderthals had abilities usually attributed solely to modern humans….”

Early age of alcohol initiation is not the cause of alcohol use disorders in adulthood, but is a major indicator of genetic risk. A population-based twin study.“The association between early age of alcohol initiation and alcohol use disorders in later life does not reflect a causal relationship, but is due almost entirely to common genetic risk factors.”

α-Actinin-3: Why Gene Loss Is an Evolutionary Gain – h/t billare! who tweeted: “Positive selection for broken proteins: Derived ACTN3 mutation seems to help fast-twitch muscles fatigue less slowly.”

Do viruses make us smarter?“[R]etroviruses seem to play a central role in the basic functions of the brain, more specifically in the regulation of which genes are to be expressed, and when.”

Estimating the genotypic intelligence of populations and assessing the impact of socioeconomic factors and migrations – from davide piffer who tweeted: “New version of my paper with genetic distances. Migrations or drift less likely to explain results.” also, from the paper: “The results also provide preliminary evidence in favor of the hypothesis that poor environmental conditions (i.e. economic and sociocultural) tend to depress national IQ scores. Countries with lower per capita GDP and a lower index of Human Development tended to have larger positive ‘residuals’, that is the difference between the score predicted by the regression (of IQs for developed countries on the 4 SNPs g factor) and the actually measured IQ was larger in countries with lower GDP and HDI (r around 0.7). Thus, poorer and less developed countries have yet to reach their full intellectual potential. The results of this study indicate that the gaps in intellectual performance between some populations can be narrowed via adequate improvement of environmental conditions, however the overall pattern of intellectual scores is due to relatively stable and fixed (genetic) factors and cannot be substantially altered.” – see also terrific post from anatoly karlin on this paper!: Genetics, IQ, and Convergence.

Evidence of polygenic selection on human stature inferred from spatial distribution of allele frequencies – also from davide piffer.

Geographical Variation in Dementia: Examining the Role of Environmental Factors in Sweden and Scotland“We found a 2- to 3-fold geographical variation in dementia odds in Sweden, after twin random effects — likely to capture genetic and shared environmental variance — were removed. In Scotland, we found no variation in dementia odds in childhood but substantial variation, following a broadly similar pattern to Sweden, by adulthood. Conclusion: There is geographical variation in dementia rates.” – h/t erwin schmidt! – also Genetics and Underlying Pathology of Dementia.

Archaeogenomic insights into the adaptation of plants to the human environment: pushing plant–hominin co-evolution back to the Pliocene“The colonization of the human environment by plants, and the consequent evolution of domesticated forms is increasingly being viewed as a co-evolutionary plant–human process that occurred over a long time period, with evidence for the co-evolutionary relationship between plants and humans reaching ever deeper into the hominin past. This developing view is characterized by a change in emphasis on the drivers of evolution in the case of plants. Rather than individual species being passive recipients of artificial selection pressures and ultimately becoming domesticates, entire plant communities adapted to the human environment.” – h/t george perry!

Son of Edar“[S]omebody should look for characteristic racial differences in tears, sebaceous glands, Meobomian glands, and salivary glands. And possibly fingernails. They may well exist, be driven by this EDAR mutation, and some might play a role in its selective advantage.” – from greg cochran.

Quality vs Quantity“To the extent that human capital is a product of genetic factors (quite a lot), this tradeoff *does not exist*.” – also from greg cochran.

Lower mortality rates among Asian, Hispanic lupus patients“Asian and Hispanic patients with systemic lupus erythematosus (SLE) have lower mortality rates compared to Black, White, or Native Americans with the disease, scientists have found. Findings indicate that the risk for death among White patients is much lower than in Black and Native American SLE patients.”

Genetic errors linked to more ALS cases than scientists had thought – h/t jayman!

Is your face special?“Face recognition is highly heritable and weakly related to *g* so it probably has its own module, or a favoured set of circuits which only partly taps into the central processor power of general intelligence. So, not only is your face is special. but your specialised ability to recognise faces is even more special.” – from dr. james thompson.

Are flu shots effective? Your genetics determine how the immune system responds

Environment, more than genetics, shapes immune system“Everyone’s immune system is slightly different—a unique mixture of hundreds of these cells and proteins. But the main driver of this variation is unclear. Although scientists know that our immune system can adapt to our environment—that’s why vaccines work, for instance—it is also built by our genes…. After recruiting 210 identical and fraternal twins between 8 and 82 years old, Davis and colleagues took blood samples and measured more than 200 parameters of their immune systems. For example, they measured the numbers of 95 kinds of immune cells and 51 kinds of proteins. Today, the researchers report online in Cell that identical twins’ immune systems were too different for the variation to boil down to genetics. Indeed, environment overshadowed inheritance in three-quarters of the measurements, and half showed no measurable genetic influence. Moreover, younger twins were more similar than were older twins, evidence that as the twins aged and were exposed to different environments, their immune systems diverged over time.”

Levels of Selection Are Artefacts of Different Fitness Temporal Measures“I show by comparing the fitness of individuals with that of collectives of individuals in the same environment and over the same period of time – as required to decide if one or more levels of selection is acting in a population – that the selection of collectives is a by-product of selection at the individual level; thus, talking about two or more levels of selection represents merely a different perspective on one and the same process.”

Does incidental disgust amplify moral judgment? A meta-analytic review of experimental evidence [pdf] – “We meta-analyzed all available studies, published and unpublished, that experimentally manipulated incidental disgust prior to or concurrent with a moral judgment task (k=50). We found that there is evidence for a small amplification effect of disgust (d=.11), which is strongest for gustatory/olfactory modes of disgust induction. However, there is also some suggestion of publication bias in this literature, and when this is accounted for, the effect disappears entirely (d=-.01). Moreover, prevalent confounds mean that the effect size that we estimate is best interpreted as an upper bound on the size of the amplification effect. The results of this meta-analysis argue against strong claims about the causal role of affect in moral judgment and suggest a need for new, more rigorous research on this topic.” – h/t stuart ritchie!

The DNA photofit: Amazing breakthrough means police can tell suspect’s colour, height and even age – from a tiny speck of blood – daily mail.

The Coming Stability? The Decline of Warfare in Africa and Implications for International Security“The years 2010–2013 saw an increase of 35 per cent in African battle deaths over 2005–2010, but they still are 87 per cent lower than the 1990–1999 average…. Consequently, there is no Africa exception to the systemic shift towards lower levels of armed conflict.” – h/t mugwump!

The Scariest Explanation for America’s Vast Prison Population: We Want It That Way“[I]n federal prisons at least, Hispanics have overtaken blacks in the dubious distinction of being the most disproportionately imprisoned. Nor can we blame the war on drugs. The idea that vast numbers of Americans are in prison for smoking pot or snorting blow turns out to be a fantasy. About 20 percent of inmates are in for drug-related crimes, but those crimes are rarely limited to their own casual use. According to a 2004 estimate, only about 12,000 people were incarcerated for simple possession, without intent to traffic or distribute.”

Sorry, liberals, Scandinavian countries aren’t utopias“Finland, which tops the charts in many surveys (they’re the least corrupt people on Earth, its per-capita income is the highest in Western Europe and Helsinki often tops polls of the best cities), is also a leader in categories like alcoholism, murder (highest rate in Western Europe), suicide and antidepressant usage….” – [huh. even with all that tango dancing!] – “It turns out that the ‘warrior gene’ — actually the enzyme monoamine oxidase A, which is linked to impulsive behavior, violence and alcoholism — is especially prevalent in Finland. ‘Dark’ doesn’t just describe winter in the Arctic suburbs, it applies to the Finnish character.” – h/t ninja economics!

The relationship between anti-gay prejudice and the categorization of sexual orientation“[I]ndividuals reporting higher levels of anti-gay bias appear to be less accurate judges of sexual orientation.” but “Italians reporting greater anti-gay bias miscategorized fewer gay faces as straight.” – h/t ben southwood!

Legal Recognition of Same-Sex Couples and Family Formation“It has long been debated how legalizing same-sex marriage would affect (different-sex) family formation. In this article, I use data on OECD member countries for the period 1980–2009 to examine the effects of the legal recognition of same-sex couples (through marriage or an alternative institution) on different-sex marriage, divorce, and extramarital births. Estimates from difference-in-difference models indicate that the introduction of same-sex marriage or of alternative institutions has no negative effects on family formation…. In addition, the country-by-country case studies provide evidence of homogeneity of the estimated effects.”

Pair-Bonding, Romantic Love, and Evolution – The Curious Case of Homo sapiens“We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens.”

Sex ratio effects on reproductive strategies in humans – among the makushi people of guyana.

Antiquity of dairy farming in Ireland revealed“Research published today in the Journal of Environmental Archaeology shows that dairying on the island goes back approximately 6,000 years, revealed through traces of ancient dairy fats found in pots dating to around 4,000 to 2,500 BC.” – h/t frau katze!

The origin and evolution of maize in the American Southwest

A Breeder Apart: Farmers Say Goodbye to the Bull Who Sired 500,000 Offspring“Fans Commemorate ‘Toystory,’ a Dairy Legend With a Ravenous Libido” – the genghis khan of bulls! h/t mr. robert ford!

Items lost in the Stone Age are found in melting glaciers“Mittens, shoes, weapons, walking sticks – lost in the high mountains of Norway thousands of years ago – are now emerging from melting ice.”

bonus: ‘I can haz genomes’: cats claw their way into genetics“Canine dominance bows to tabby chic as cat sequencing takes off.”

bonus bonus: Some Microbes Can Eat And Breathe Electricity – whoa.

bonus bonus bonus: Britain’s oldest person Ethel Lang dies aged 114“Ethel Lang was believed to be the last person living in the UK who was born in the reign of Queen Victoria.” – h/t ed west!

bonus bonus bonus bonus: Two New Studies Posit At Least Two New Planets Out Beyond Pluto

bonus bonus bonus bonus bonus: Whaleworld: Looking for cetacean culture – h/t steve stewart williams! who tweeted: “Millions of years before human culture appeared, there was culture in the ocean.” – cool!

bonus bonus bonus bonus bonus bonus: Medieval Apps.

bonus bonus bonus bonus bonus bonus bonus: Archaeologists find 132-year-old Winchester rifle leaning against Nevada desert tree

bonus bonus bonus bonus bonus bonus bonus bonus: Irn Bru release 57 Scottish tartan labels and clan finder website promotion (~_^)

bonus bonus bonus bonus bonus bonus bonus bonus bonus: “At some German crossings you can play a game of Pong with the person standing at the other side.” (^_^)

bonus bonus bonus bonus bonus bonus bonus bonus bonus bonus: If birds in a truck fly, does the truck get lighter? – hey…don’t bogart that joint, new scientist!

bonus bonus bonus bonus bonus bonus bonus bonus bonus bonus bonus: Kareem Abdul-Jabbar to Publish a Novel About Sherlock Holmes’s Brother Mycroft – danced a few dances with kareem! (^_^) (not a euphemism. for anything!)

(note: comments do not require an email. i can haz genomz?)

linkfest – 12/07/14

Zigzags on a Shell From Java Are the Oldest Human Engravings“The early human Homo erectus also made the oldest known shell tools half a million years ago.” — see also: The art of Homo erectus“What we can say is that these artifacts carry information about the capabilities of their makers. The few non-perishable marked objects also speak to the likely presence of design in perishable elements of material culture. Clothing, however rudimentary, was likely to have been decorated in some way. Wooden tools were also probably notched and zigzagged — as the occasional bone and ivory implements suggest. They lived for the first time in a world that they could change.” – from john hawks.

Genetic diversity of Sub-Saharan Africa revealed[T]he researchers also found that there were more genetic similarities across Africa than they had thought. Dr Sandhu said: ‘The diversity among populations is not as diverse as we expected it to be….’ The researchers found that many Africans have some Eurasian DNA within their genetic ancestry, which suggests that Eurasians migrated back into Africa many thousands of years after they first left. And several of the populations were descended from the Bantu, a group that spread across Africa about 5,000 years ago.” — see also: The African Genome Variation Project shapes medical genetics in Africa.

and here is dienekes on the above study: African Genome Variation project paper“In too many papers to count, decreasing genetic diversity from East Africa was taken as evidence of an origin of H. sapiens in that locality and its expansion from there to Eurasia. This ‘East Africa=cradle of mankind’ theory has, as far as I can tell, nothing really to stand on. Granted, the oldest anatomically modern human remains have been found in East Africa 200-150 thousand years ago. But, the fact that old sapiens have been found in East Africa and not elsewhere is easily explained by the excellent conditions for preservation (as opposed, e.g., deserts or rainforests of Africa or elsewhere), and by the extraordinary effort by palaeoanthropologists in that area. One also needs to overlook a century of physical anthropology that concluded that East Africa was a contact zone between Caucasoids and Sub-Saharan Africans. We now know that there is no deep lineage of humans in modern east Africans. Take out the Eurasian ancestry and only a paltry Fst=0.027 remains with other Sub-Saharan Africans, a fraction of the Fst between, say, Europeans and East Asians.”

Living African group discovered to be the most populous humans over the last 150,000 years“New genetic research reveals that a small group of hunter-gatherers now living in Southern Africa once was so large that it comprised the majority of living humans during most of the past 150,000 years. Only during the last 22,000 years have the other African ethnicities, including the ones giving rise to Europeans and Asians, become vastly most numerous…. ‘This and previous studies show that the Khoisan peoples and the rest of modern humanity shared their most recent common ancestor approximately 150,000 years ago, so it was entirely unexpected to find that this group apparently did not intermarry with non-Khoisan neighbors for many thousand years….'” — see also The Least Bottlenecked Humans of All from razib.

Ants, altruism and self sacrifice“It’s the selfishness of genes that makes us unselfish…. ‘Group selection’ has always been portrayed as a more politically correct idea, implying that there is an evolutionary tendency to general altruism in people. Gene selection has generally seemed to be more of a right-wing idea, in which individuals are at the mercy of the harsh calculus of the genes. Actually, this folk understanding is about as misleading as it can be. Society is not built on one-sided altruism but on mutually beneficial co-operation. Nearly all the kind things people do in the world are done in the name of enlightened self-interest. Think of the people who sold you coffee, drove your train, even wrote your newspaper today. They were paid to do so but they did things for you (and you for them). Likewise, gene selection clearly drives the evolution of a co-operative instinct in the human breast, and not just towards close kin.” – from matt ridley. — see also: E.O. Wilson’s The Social Conquest of Earth from jason collins. h/t billare!

Genetic Variation in Human DNA Replication Timing“Replication timing, a driver of locus-specific mutation rates, varies among humans…. Replication timing associates with common polymorphisms near replication origins….” – whoa.

Genetic and environmental exposures constrain epigenetic drift over the human life course – h/t casey brown! who tweeted: “Worth repeating: DNA methylation is more genetic than epigenetic.”

IQ is in the genes“How parents raise us has no impact on how smart we become, a new study finds.”

Link discovered between fathers’ criminal history and sons’ intelligence“Sons whose fathers have criminal records tend to have lower cognitive abilities than sons whose fathers have no criminal history, data from over 1 million Swedish men show. The research, conducted by scientists in Sweden and Finland, indicates that the link is not directly caused by fathers’ behavior but is instead explained by genetic factors that are shared by father and son.”

Are bright people normal?“‘We found no support for the genetic Discontinuity Hypothesis that nonadditive genetic variance is greater for high intelligence….'” – from dr. james thompson.

Booze culture may date back 10 million years say scientists“A new study suggests that primates may have begun drinking alchol 10 million years ago, as fermented fruit on the forest floor…. Experts at Santa Fe College in the US studied the gene ADH4 which produces an enzyme to break down alcohol in the body. It was hypothesised that the enzyme would not appear until the first alcohol was produced by early farmers. But scientists were amazed to find it 10 million years earlier, at the end of the Miocene epoch.” – (them’s *my* ancestors right there! (~_^) )

Psychiatry: End of the Road for “Endophenotypes”?“In a nutshell, the researchers ran seven different genetic studies to try to find the genetic basis of a total of seventeen neurobehavioural traits, also known as ‘endophenotypes’…. Essentially an endophenotype is some trait, which could be almost anything, which is supposed to be related to (or part of) a psychiatric disorder or symptom, but which is ‘closer to genetics’ or ‘more biologica’ than the disorder itself. Rather than thousands of genes all mixed together to determine the risk of a psychiatric disorder, each endophenotype might be controlled by only a handful of genes – which would thus be easier to find…. Over 89% of the searches came up null in this way; for eight of the seventeen traits, the researchers found no associated genes using *any* strategy.” – from neuroskeptic.

Unequal fates for maths superstars“The fates of US child prodigies of the 1970s reveal great accomplishments but strong gender differences…. [B]oth genders reported unusually high levels of satisfaction with their lives and careers. ‘It seems that both sexes got what they wanted from life, even if those things were somewhat different….'” – h/t charles! – see also: Sometimes men and women want different things from ben southwood.

Are Chinese babies more docile? – peter frost on the freedman studies.

Inferior Faunas – from greg cochran.

Transparency International’s Corruption Perceptions Index 2014 released this week.

Domestication and Human Evolution Symposium @getCARTA sessions now available to watch online.

Does evolution need a revolution? – from jerry coyne.

Experimentally induced innovations lead to persistent culture via conformity in wild birds – birds have culture.

A Magisterial Synthesis Of Apes And Human Evolution“[Russell H.] Tuttle’s tome is a grand synthesis of all the latest research and data about apes and their relation to us…. He believes that bipedalism preceded the development of the brain in early humans –and was likely something inherited from smaller apes already used to using their feet to move laterally along branches in trees. Although chimpanzees and bonobos are our closest relatives on the evolutionary tree, they do not represent in their own locomotion good proto-models of what led to human upright posture and walking.”

‘Superbugs’ Kill India’s Babies and Pose an Overseas Threat“A growing chorus of researchers say the evidence is now overwhelming that a significant share of the bacteria present in India — in its water, sewage, animals, soil and even its mothers — are immune to nearly all antibiotics.” – h/t razib!

The RNA World: molecular cooperation at the origins of life“The RNA World concept posits that there was a period of time in primitive Earth’s history — about 4 billion years ago — when the primary living substance was RNA or something chemically similar. In the past 50 years, this idea has gone from speculation to a prevailing idea. In this Review, we summarize the key logic behind the RNA World and describe some of the most important recent advances that have been made to support and expand this logic. We also discuss the ways in which molecular cooperation involving RNAs would facilitate the emergence and early evolution of life.”

Tool to edit DNA revolutionizing research in Boston area – CRISPR.

Thomas Docherty on academic freedom“Managerial fundamentalism has taken hold in universities, with scholars viewed as resources that must be controlled…. A creeping incremental assault on academic freedom threatens not just what can be spoken aloud, but also what it is permissible to think: thought itself is to be subjected to management, so that its critical power is neutered or constrained….”

The Dark Enlightenment for Newbies“So what is dark about the Dark Enlightenment? Absolutely nothing. The Dark Enlightenment only looks dark in contrast to the blinding (as in, it blinds you) optimism of flash in the pan of blank slate equalism. The things that the DE contend about human nature — that parents naturally favor their children, that sexual attraction is a biological phenomenon, that some people are naturally smarter than others — were all accepted as common sense for most or all of human history. It is the unrealistic utopianism of modern liberalism which is ridiculously absurd. The Dark Enlightenment might be better termed The Return to Normalcy. So the phrase “Dark Enlightenment” might not be the best, but it has received enough attention that I don’t think we should abandon it.” – very nice post from empedocles.

Tanzania evicting 40,000 people from homeland to make room for Dubai royal family“It will become a private hunting reserve” – =/ (i’m linking to salon!) – h/t john durant!

bonus: Why Some Mosquitoes Spread Malaria and Others Don’t“Sequencing the genomes of numerous Anopheles mosquito species from locations around the world has shown why some can carry and spread the deadly disease malaria while others don’t.” – h/t srikant mantri!

bonus bonus: Humpback Whales in the Arabian Sea Have Been Isolated for 70,000 Years

bonus bonus bonus: A diet to die for“One bird feasts on food that would leave most other animals stone dead.”

bonus bonus bonus bonus: Insect Swarms Go Critical“Scientists have found tantalizing evidence that diverse biological systems, including the human brain, gene expression networks, bird flocks, and fish schools, behave as though they are near the ‘critical point’ of a phase transition, like correlated spins in a magnet on the verge of ordering.” – h/t jayman!

bonus bonus bonus bonus bonus: Weird Physics Can Make an Invisible Cat Visible“These cat pictures are brought to you by quantum entanglement as discussed by Einstein and Schrödinger.”

bonus bonus bonus bonus bonus bonus: “The Feynman Lectures on Physics”, The Most Popular Physics Book Ever Written, Now Completely Online

bonus bonus bonus bonus bonus bonus bonus: Tette per la Scienza – boobies! (it really IS this time! (~_^) )

(note: comments do not require an email. quantum cats!)

spiders from mars?

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!)

linkfest – 03/10/13

Low-hanging fruit?“We need to go beyond intelligence and look at genetic differences that may underlie variation in personality traits, regulation of emotions, time orientation, and so forth. There is more to being human than just intelligence. – yes!! (^_^) – from peter frost.

this is kinda old (from jan) but i just came across it: Variants at serotonin transporter and 2A receptor genes predict cooperative behavior differentially according to presence of punishment“We show that variants at the serotonin transporter gene (SLC6A4) and serotonin 2A receptor gene (HTR2A) predict contributions to the public good in economic games, dependent upon whether contribution behavior can be punished.”

Genetic Influences on the Overlap Between Low IQ and Antisocial Behavior in Young Children“Genetic influences common to both phenotypes explained 100% of the low IQ–antisocial behavior relation in boys.” – via race/history/evolution notes.

Monkeys Stay Away from Mean People“Capuchin monkeys show biases against humans who deny help to others.”

Genetic study of house dust mites demonstrates reversible evolution

Do species exist? – from steve sailer.

Fungus, Get Off My Lawn!“Virginia wildrye, common on U.S. prairies and rangelands, often plays host to a fungus that helps this grass grow. But the plant pays a price. Researchers have discovered that infected plants produce less pollen than their noninfected counterparts. Instead, the fungus causes the rye grass to make extra seeds, which transmit the fungus to the next generation and new locations. This is the first time a fungus has proven capable of manipulating plant reproduction.” – manipulator!

E. O. Wilson vs. Jerry Coyne: The Group Selection Wars Continue – from helian.

Pathogens: Cause or Effect of Social Variation?

Can People’s Personalities Change?“[P]ersonality was the strongest predictor of satisfaction with life. This is well-established and helps explain why some people have everything and are never satisfied and some people have next-to-nothing and seem quite happy with life. It’s not just what you have that makes you satisfied (or not), it’s how you think about it. And those habits of thought are heavily influenced by personality.”

Difficult Thoughts“It’s depressing to see how irrational we are so much of the time, but there it is.” – from malcolm pollack.

The Shape of History“Ian Morris, historian on a grand scale.”

bonus: Mystery bug found in Antarctica’s Lake Vostok“There is something alive in Lake Vostok, deep beneath the East Antarctic ice sheet, and we don’t know what it is. Water samples from the lake contain a bacterium that does not seem to belong to any known bacterial groups….”

bonus bonus: The Dark Enlightenment and the Eco Fringe – paleo retiree goes all hippie on us. (~_^) (i’ll confess right now to being a tree hugger myself.)

bonus bonus bonus: foseti’s drunken rant – i love drunken rants! (~_^) (this one actually makes sense!)

bonus bonus bonus bonus: Only the toughest would survive on Tatooine worlds – h/t hbd bibliography!

bonus bonus bonus bonus bonus: Butt munchers“[S]ea cucumbers can eat through their anuses.”

(note: comments do not require an email. sea cucumber – i don’t know if that’s the front end or the back….)

linkfest – 10/16/11

E. O. Wilson’s Theory of Everything

Breathing life into an extinct ethnicity“Participants in the 1000 Genomes project reconstruct the genetic variation of a lost group of Native Americans.” – the tainos.

Children Like Teamwork More Than Chimps Do

Smoking cannabis could make you depressed depending on your genes

The Drive to Be Different

Does the Pill make you choose a boring lover? Scientists find women who take the contraceptive pick caring and reliable men

bonus: What are you doing about HBD-denialism? – from half sigma.

bonus bonus: HBD defined – from mr. a. epigone, esq.

(note: comments do not require an email. the drive to be different. (~_^) )

“the selfish gene”

i recently persuaded someone of my acquaintance to read dawkins’ “The Selfish Gene,” and as i’m guessing — or, rather, hoping — that they’ll prolly want to discuss it, i’ve started re-reading it — refresh the ol’ memory (i read it several years ago now).

i also decided that i may as well babble about it here, too, since it’s right on topic! (^_^) i’m sure most or many of you have already read it, but if you haven’t, i suggest you run out (or log on to amazon) and buy it asap! (or check it out of the library!) it’s a marvelous book, even tho it has its faults (mostly because dawkins has his faults. heh — don’t we all?).

so, chapter one (i’ve got the 1989 edition, reissued in 1999): “Why are people?” i think the three most interesting points he introduces in this chapter are the individual vs. group selection debate, inclusive fitness being the reason for many altruistic behaviors, and how much genes “control” our altruistic (or not) behaviors.

the individual vs. group selection debate? i dunno — i’m about as familiar with it as, i think, a non-specialist layperson can be, but i’m really in no position to come to a conclusion about who’s right or who’s wrong here. i know that most evolutionary biologists have concluded that natural selection operates only on individuals (or, really, on genes) and not groups, but that there is a minority group (messrs. wilson, et. al.) who object.

i’m staying agnostic on the issue for now because i’m neurotic i just don’t have the knowledge base to conclude one way or another. individual selection sure makes logical sense to me, like i say, as a layperson. and i haven’t given much thought to group selection, really. but i will note that both william hamilton and george price seemed persuaded by it — or, at least, didn’t rule it out. from hamilton’s “Narrow Roads of Gene Land, Vol. 1” (this is as quoted by david sloan wilson, btw):

“A manuscript did eventually come from him [price] but what I [hamilton] found set out was not any sort of new derivation or correction of my ‘kin selection’ but rather a strange new formalism that was applicable to every kind of natural selection…. His voice was squeaky and condescending, rather guarded on the phone…. He spoke of his formula as ‘surprising for me too — quite a miracle’ … ‘Have you seen how my formula works for group selection?’ I told him, of course, no, and may have added something like: ‘So you actually believe in that do you?’ Up to this contact with Price, and indeed for some time after, I had regarded group selection as so ill-defined, so woolly in the uses made by its proponents, and so generally powerless against selection at the individual and genic levels, that the idea might as well be omitted from the toolkit of a working evolutionist….

“I am pleased to say that, amidst all else that I ought to have done and did not do, some months before he died I was on the phone telling him enthusiastically that through a ‘group-level’ extension of his formula I now had a far better understanding of group selection acting at one level or at many than I had ever had before.”

well, if it was good enough for william hamilton….
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now — inclusive fitness and how that leads to altruistic or selfish behaviors. this from dawkins relates to individuals vs. groups again [pg. 8]:

“The individual-selectionist would admit that groups do indeed die out, and that whether or not a group goes extinct may be influenced by the behavior of the individuals in that groups. He might even admit that if only the individuals in a group had the gift of foresight they could see that in the long run their own best interests lay in restraining their selfish greed, to prevent the destruction of the whole group…. But group extinction is a slow process compared with the rapid cut and thrust of individual competition. Even while the group is going slowly and inexorably downhill, selfish individuals prosper in the short term at the expense of altruists…. [E]volution is blind to the future.”

well, this is related to what i was complaining about the other day — that people have no foresight! at least not when it comes to thinking about the fate of humanity a hundred or hundreds of years into the future. but i understand — how on earth would that ever be selected for when you’ve got individuals vs. individuals in everyday life?

*sigh*
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my big complaint about dawkins is that his opinion on the nature vs. nurture debate leans too far towards the nuture side for my tastes. thus his crusade against religion (good luck with that!) — and his belief that we might be able to fight our altruism/non-altruism genes. well, yeah, maybe a bit — but dawkins really thinks such a thing would be possible [pg. 3]:

“As a corollary to these remarks about teaching, it is a fallacy — incidentally a very common one — to suppose that genetically inherited traits are by definition fixed and unmodifiable. Our genes may instruct us to be selfish, but we are not necessarily compelled to obey them all our lives. It may just be more difficult to learn altruism than it would be if we were genetically programmed to be altruistic.”

meh.

rushton, et. al., found that the heritability of altruistic behavior was something like 50% (in modern britons in the 1980s). seems like altruistic behaviors, then, like many of our personality traits and behaviors, are pretty strongly heritable. no one’s gonna change that fact that much by edumacation or culture or anything like that. if anything, the more environmental circumstances for individuals were to be equalized (either make society wonderful and easy for everybody, or make it an absolute dog-fight for everybody) the more the genetics would come into play — ironic but true.

also, whether or not individuals behave altruistically shifts (on average) depending upon with whom they are interacting — that’s the whole point of inclusive fitness! interact with a family member and an individual is likely to be pretty altruistic — interact with a stranger and eh … not so much altruism.

therefore, make a society multi-cultural and you just have to expect altruism to drop. especially in bad economic times. people can afford to be pretty altruistic when times are good. when times are bad — look out. you’re just never going to get everyone to be altruistic under such circumstances. not without some futuristic genetic engineering or something! teaching people to be altruistic ain’t gonna cut it. (of course, there’s reciprocal altruism, too, but since that’s based even more directly on “what’s in it for me?” sort-of thinking, i would think that’ll be the first to go in dire economic times.)
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btw, one of the best parts of “The Selfish Gene” is the cover! at least on the edition that i have. look! LOWERCASE letters only in the title! (~_^)

update 10/04: see also “the replicators”

(note: comments do not require an email. altruism — workin’ for this guy!)