Happy Darwin Day!
"You don't use science to show that you're right, you use science to become right."
-- from the web comic XKCD.
Also this week:
Darwinian Evolution of Prions in Cell Culture
Any set of replicators with heritable differences affecting survival and reproduction can evolve.
Reconstructing the ups and downs of primate brain evolution: implications for adaptive hypotheses and Homo floresiensis
Mapping trends in brain size on the primate family tree shows more increases are more common than decreases, but both have occurred. "Hobbits" could be an example of a decrease.
Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids
Fish that eat scales from the left or right side of other fish have asymmetric jaws; they've found the gene responsible for this "handedness."
Organic-walled microfossils in 3.2-billion-year-old shallow-marine siliciclastic deposits
They're really old, they're really big (probably visible without magnification, but apparently some bacteria get that big), and maybe they were once alive.
A Composite of Multiple Signals Distinguishes Causal Variants in Regions of Positive Selection
Various methods can show that some large DNA sequence has increased under natural selection, but can't usually narrow it down to a particular gene. Combining methods can help.
A bony connection signals laryngeal echolocation in bats
Some bats (including the big ones we saw recently in Brisbane) don't use sonar. But what about bat species known only from fossils? Different species "ping" in different ways, but a connection between two bones appears to have a consistent link to echolocation.