How and when did Bantu populations expand through sub-Saharan Africa? Using phylogeographic analyses, the authors test four main hypotheses which aim to explain the route that the Bantu took as well as the date of expansion. The results suggest that Bantu populations migrated through the Central African rainforest around 4,400 years ago.

How and when did Bantu populations expand through sub-Saharan Africa? Using phylogeographic analyses, the authors test four main hypotheses which aim to explain the route that the Bantu took as well as the date of expansion. The results suggest that Bantu populations migrated through the Central African rainforest around 4,400 years ago.

How and when did Bantu populations expand through sub-Saharan Africa? Using phylogeographic analyses, the authors test four main hypotheses which aim to explain the route that the Bantu took as well as the date of expansion. The results suggest that Bantu populations migrated through the Central African rainforest around 4,400 years ago.

Through phylogenetic comparison, Holden and Mace explore the relationship between descent and cattle among a sample of 68 Bantu/Bantoid-speaking populations in Africa. The authors posit that when matrilineal cultures adopt cattle, they become patrilineal. Possible theories are offered to explain trends and variation in the data.

Several theories on the development of matrilocal residence are tested. The main argument put forth predicts that matrilocal residence will develop in response to a need to break up fraternal interest groups that encourage internal war and instead encourage a pattern of external war that is more beneficial in populated regions with additional group migration.

This paper examines the enormous variation in linguistic diversity among Pacific Islands by testing its relationship with various environmental variables put forth in several common theories of language richness. The researchers identify variables relating to land area and island isolation as accounting for about half of variation in linguistic diversity, suggesting that the other half is a result of complex social factors.

The researchers utilize a GIS approach in order to examine the relationship between global linguistic distribution and various cultural and environmental factors. The resulting positive association between political complexity and both latitude and language range leads the researchers to propose that large, politically complex entities exert a homogenizing pressure on language. However, the causal link may also be in the other direction, with possession of common language facilitating the creation of more complex political institutions.

In order to investigate cross-cultural variation in systems of conversational turn-taking (who speaks and when), the researchers analyze the association of various contextual, verbal, and non-verbal factors with mean response time. Despite some variation in response time between languages, each of the explanatory variables is found to have significant impact on response time independent of language. A further test on subjective perception of ideal response time suggests that although similar factors act on response patterns cross-culturally (in support of a 'universal systems' theory), speakers are hypersensitive to even minor cultural variations in response time.

The researchers utilize a GIS approach in order to examine the relationship between global linguistic distribution and various cultural and environmental factors. The resulting positive association between political complexity and both latitude and language range leads the researchers to propose that large, politically complex entities exert a homogenizing pressure on language. However, the causal link may also be in the other direction, with possession of common language facilitating the creation of more complex political institutions.

The researcher looks for empirical evidence of natural selection as an explanation for worldwide variation in novelty-seeking behavior. Examining the relationship between variability in frequency of the DRD4 exon III 7-repeat allele variant (a variant theorized to stifle dopamine reception and thus encourage compensatory novelty-seeking behavior) and migratory distance from prehistoric humans' origin point in East Africa yields a positive correlation. After controlling for various biogeographic indicators, the researcher theorizes that presence of the DRD4 exon III 7-repeat variant provided an exploratory urge and evolutionary advantage to hunter-gatherers and pastoralists who migrated into unfamiliar environments.