New insights on speciation in birds

New research published in PNAS looks at the rate at which genetic differences accumulate in populations of birds. Here is a summary of the work. And here's the original paper. The researchers assessed the rate of genetic differentiation in 173 species of birds, and then showed that higher rates of genetic differentiation correlate with higher speciation rates over longer timescales.

H. sapiens might be older than we thought

Human remains found in Morocco at a site called Jebel Irhoud suggest that our species might be much older than anyone thought--possibly 300,000 years old. Here is a summary of the work. Here is the paper in Nature. And here is a second paper that covers the techniques used to date the remains. The researchers used thermoluminescence dating on lithics that were associated with the human skeletal remains. 

T. rex had scaly skin

It turns out that T. rex and its close relatives were probably not fully covered in feathers (though they might still have had some). Here is a popular report on recent work on preserved Tyrannosaur skin. Here's the original paper. 

Wherein Turner wins a thing, and we embarrass him

“one of the most productive, original and well-respected scholars in multiple emerging subfields in the philosophy of science.”


The Phylogeny of H. floresiensis

A new paper in the Journal of Human Evolution presents evidence against the hypothesis that the  "Hobbits" of the island of Flores are descended from H. erectus. Instead, the authors argue that we have to go deeper into the family tree to find the common ancestor that we humans share with H. floresiensis. Here's an accessible summary of the findings.

Rethinking the dinosaur family tree

A new study published in Nature challenges the deeply entrenched distinction between ornithischian and saurischian dinosaurs. What if therapods were more closely related to ornithischian dinosaurs than they were to sauropods? Here is a nice discussion of the research in The Atlantic.

Pinning down the timing of the bison invasion of N. America

A recent paper in PNAS uses ancient DNA research to determine when bison first "invaded" North and South America. The iconic symbols of the N. American west haven't actually been here that long. It turns out that the first migration of bison from Asia occurred between 195 and 135 thousand years ago. Here is a shorter report on the research from The New York Times.

Canadian microfossils might be 3.77 billion years old

Scientists keep pushing back the age of the earliest known fossils, which also suggests earlier and earlier dates for the first appearance of life on Earth. A new paper in Nature reports on microfossils from Canada alleged to be almost 3.8 billion years old. (Here is an accessible discussion in The Washington Post.)

Evolving Flight: Messier Than You Might Think...

Getting from a little theropod-thing to a fully-powered flying bird-thing is often presented as a pretty direct trajectory, as "as a long evolutionary march in which natural selection progressively refined one subgroup of dinosaurs into ever-better aerialists". In a new paper in science, Stephen Brusatte argues that recent fossil finds suggest that things were way crazier than that...