Thursday, November 19, 2009
Recently, two simultaneous studies came to the conclusion that the close relationship of Rungwecebus kipungi to Papio (based on mitochondrial DNA) suggest a hybrid history for the genus/species. Burell et al. 2009 suggest that the kipungi was the result of hybridization between male mangabeys (probably Lophocebus) and female baboons. Zinner et al. 2009, on the other hand, suggest the possibility that the kipungi is a basal member of the Papio clade and fairly recently (until 0.35 million years ago) male kipungis were breeding with female baboons. In this study, Roberts and colleagues include DNA from a separate population of kipungis and find that only one population shows signs of hybridization, suggesting that the originally sampled population did, in fact, hybridize as Zinner and colleagues suggested. However, the newly sampled population shows no signs of hybridization, suggesting that the origins of kipungis were not results of mangabey/baboon hybridization.
Tuesday, November 10, 2009
The association of EDAR 1540C with dental morphology is investigated, and the study indicates that the number of EDAR 1540C alleles is correlated with tooth-shoveling grade. Read all about it!
Galindo and colleagues show that global microsatellite content varies predictably by species, with most major differences occurring in developmental regions. Though further study is needed, they suggest that it might be fruitful to look at how global microsatellite content relates to different phenotypes.
The authors looked at 13400 genes in two human populations for evidence of balancing selection; in particular, they looked for evidence of excess polymorphism and intermediate-frequency alleles. They find 60 candidate genes, and not surprisingly, many factor into immune function, though others encode keratin and membrane channels. Interestingly, they also find possible evidence for population differences in balancing selection between the two groups in 13 of the candidate genes.