Doubts about complex speciation between humans and chimpanzees

Doubts about complex speciation between humans and chimpanzees.

Two patterns from large-scale DNA sequence data have been put forward as evidence that speciation between humans and chimpanzees was complex, involving hybridization and strong selection. First, divergence between humans and chimpanzees varies considerably across the autosomes. Second, divergence between humans and chimpanzees (but not gorillas) is markedly lower on the X chromosome. Here, we d...

An autosomal analysis gives no genetic evidence for complex speciation of humans and chimpanzees.

There have been conflicting arguments as to what happened in the human-chimpanzee speciation event. Patterson et al. (2006, Genetic evidence for complex speciation of humans and chimpanzees. Nature 441:1103-1108) proposed a hypothesis that the human-chimpanzee speciation event involved a complicated demographic process: that is, the ancestral lineages of humans and chimpanzees experienced tempo...

Testing the chromosomal speciation hypothesis for humans and chimpanzees.

Fixed differences of chromosomal rearrangements between isolated populations may promote speciation by preventing between-population gene flow upon secondary contact, either because hybrids suffer from lowered fitness or, more likely, because recombination is reduced in rearranged chromosomal regions. This chromosomal speciation hypothesis thus predicts more rapid genetic divergence on rearrang...

Doubts about double dissociations between short- and long-term memory.

Historically, psychologists and neuroscientists have distinguished between processes supporting memory for events across retention delays of several seconds (short-term memory, STM), and those supporting memory for events across longer retention delays of minutes or more (long-term memory, LTM). Dissociations reported in some neuropsychological studies have contributed to a popular view that th...

Doubts about dementia diagnoses.