pseudo-scientific mouthbreathing in the nytimes

Nature | Stepwise evolution of stable sociality in primates - Although much attention has been focused on explaining and describing the diversity of social grouping patterns among primates1, 2, 3, less effort has been devoted to understanding the evolutionary history of social living4. This is partly because social behaviours do not fossilize, making it difficult to infer changes over evolutionary time. However, primate social behaviour shows strong evidence for phylogenetic inertia, permitting the use of Bayesian comparative methods to infer changes in social behaviour through time, thereby allowing us to evaluate alternative models of social evolution. Here we present a model of primate social evolution, whereby sociality progresses from solitary foraging individuals directly to large multi-male/multi-female aggregations (approximately 52 million years (Myr) ago), with pair-living (approximately 16 Myr ago) or single-male harem systems (approximately 16 Myr ago) derivative from this second stage. This model fits the data significantly better than the two widely accepted alternatives (an unstructured model implied by the socioecological hypothesis or a model that allows linear stepwise changes in social complexity through time). We also find strong support for the co-evolution of social living with a change from nocturnal to diurnal activity patterns, but not with sex-biased dispersal. This supports suggestions that social living may arise because of increased predation risk associated with diurnal activity. Sociality based on loose aggregation is followed by a second shift to stable or bonded groups. This structuring facilitates the evolution of cooperative behaviours5 and may provide the scaffold for other distinctive anthropoid traits including coalition formation, cooperative resource defence and large brains.

Somehow the model published for consideration in Nature got lost in translation to become the conclusion trumpeted by human biodiversity hack Nicholas Wade in the NYTimes thus;

NYTimes | Genes Play Major Role in Primate Social Behavior, Study Finds - The Oxford survey confirms that the structure of human society, too, is likely to have a genetic basis, since humans are in the primate family, said Bernard Chapais, an expert on human social evolution at the University of Montreal.

“Evolutionary change in any particular lineage is highly constrained by the lineage’s phylogenetic history,” Dr. Chapais said, referring to the evolutionary family tree. “This reasoning applies to all species, including ours. But in humans, cultural variation hides both the social unity of humankind and its biological foundation.”

Human multifamily groups may have arisen from the gorilla-type harem structure, with many harems merging together, or from stable breeding bonds replacing sexual promiscuity in a chimpanzee-type society, Dr. Chapais said.

In his book “Primeval Kinship” (Harvard, 2008), he describes a further stage in human social evolution that occurred when individual bands allied with those with whom they exchanged daughters. The bands in such a marital exchange system formed a tribe, taking human society to a level of organization beyond that of chimpanzee society.

With chimps, territorially based bands also exchange daughters to avoid incest but continue to fight with one another to the death because the males cannot recognize their kinship with relatives in neighboring bands. Fist tap BD/Fist tap Nana.