Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

https://www.cogsci.ucsd.edu/~nunez/COGS160/Rizzolatti_Arbib_PS.pdf

Language within our grasp

How the mind works

A MUCH debated question is whether sex differences exist in the functional organization of the brain for language1–4. A long-held hypothesis posits that language functions are more likely to be highly lateralized in males and to be represented in both cerebral hemispheres in females5,6, but attempts to demonstrate this have been inconclusive7–17. Here we use echo-planar functional magnetic resonance imaging18–21 to study 38 right-handed subjects (19 males and 19 females) during orthographic (letter recognition), phonological (rhyme) and semantic (semantic category) tasks. During phonological tasks, brain activation in males is lateralized to the left inferior frontal gyrus regions; in females the pattern of activation is very different, engaging more diffuse neural systems that involve both the left and right inferior frontal gyrus. Our data provide clear evidence for a sex difference in the functional organization of the brain for language and indicate that these variations exist at the level of phonological processing.

Sex differences in the functional organization of the brain for language

Recent studies have uncovered myriad viral sequences that are integrated or 'endogenized' in the genomes of various eukaryotes. Surprisingly, it appears that not just retroviruses but almost all types of viruses can become endogenous. We review how these genomic 'fossils' offer fresh insights into the origin, evolutionary dynamics and structural evolution of viruses, which are giving rise to the burgeoning field of palaeovirology. We also examine the multitude of ways through which endogenous viruses have influenced, for better or worse, the biology of their hosts. We argue that the conflict between hosts and viruses has led to the invention and diversification of molecular arsenals, which, in turn, promote the cellular co-option of endogenous viruses.

/pdf/endogenous-viruses-insights-into-viral-evolution-and-impact-5gaglian2n.pdf

Endogenous viruses: insights into viral evolution and impact on host biology

Frequent kin-biased coalitionary behaviour is a hallmark of mammalian social complexity. Furthermore, selection to understand complex social dynamics is believed to underlie the co-evolution of social complexity and large brains. Vocalisations have been shown to be an important mechanism with which large-brained mammals living in complex social groups recognise and recruit kin for coalitionary support during agonistic conflicts. We test whether kin recognition via agonistic calls occurs in a small-brained solitary foraging primate living in a dispersed social network, the grey mouse lemur (Microcebus murinus, Miller JF, 1777). As mouse lemurs are frequent models for ancestral solitary foraging mammals, this study examines whether kin recognition via agonistic calls could be the foundation from which more complex, kin-based coalitionary behaviour evolved. We test whether female wild mouse lemurs in Ankarafantsika National Park, Madagascar, react differently to agonistic calls from kin and nonkin and to calls from familiar and unfamiliar individuals during playback experiments. Subjects showed no significant differences in reactions to the different stimuli; thus they did not react differently based upon kinship or familiarity. Results suggest that this solitary foraging species does not use agonistic calls to recognise kin and monitor agonistic interactions involving kin, unlike several species of Old World monkeys and hyenas. Thus, kin recognition via agonistic calls may have evolved independently in these lineages in parallel with greater social complexity and frequent coalitionary behaviour.

Does the grey mouse lemur use agonistic vocalizations to recognise kin

We isolated 21 microsatellites from the Milne-Edwards’ sportive lemur, Lepilemur edwardsi. Eighteen microsatellite sequences possessed sufficient flanking DNA for primer design. Seventeen loci amplified and were found to be polymorphic displaying two to 17 alleles in 32 unrelated individuals from a population from the National Park of Ankarafantsika in northwest Madagascar. One locus (Led-12) was found to be sex linked located on the X chromosome and can be used to sex-type 40% of female L. edwardsi lemurs. These 17 loci were characterized to investigate family structure and the phylogeography of L. edwardsi.

Isolation of sixteen autosomal loci and a sex‐linked polymorphic microsatellite locus from the Milne‐Edwards’ sportive lemur (Lepilemur edwardsi)

Erratum: Isolation of sixteen autosomal Ioci and a sex-linked polymorphic microsatellite locus from the Milne-Edwards sportive lemur (Lepilemur edwardsi) Corrects article in 9(1) p.333-3335

Elke Zimmermann

Papers

Does the grey mouse lemur use agonistic vocalizations to recognise kin

Isolation of sixteen autosomal loci and a sex‐linked polymorphic microsatellite locus from the Milne‐Edwards’ sportive lemur (Lepilemur edwardsi)

Erratum: Isolation of sixteen autosomal Ioci and a sex-linked polymorphic microsatellite locus from the Milne-Edwards sportive lemur (Lepilemur edwardsi) Corrects article in 9(1) p.333-3335