molecular clock
grrlscientist | March 25, 2009tags: evolutionary biology, speciation, species flocks, molecular phylogeny, behavioral ecology, Synodontis species, squeaker catfish, cuckoo catfish, Lake Tanganyika, peer-reviewed paper
The Cuckoo Catfish, Synodontis multipunctatus [Siluriformes: Mochokidae].
This is the only fish that is a known brood parasite.
This is one of the species included in this newly-published study.
Image: orphaned.
One of the groups of fishes that I worked with as an aquarist for nearly my entire life are the synodontids, often known as "squeaker catfish" for their ability to make high-pitched sounds.…
grrlscientist | February 13, 2008tags: researchblogging.org, evolution, bird-dinosaur split, dinosaurs, birds, rocks-versus-clocks, fossil record, molecular clocks
The first feathered dinosaur fossil found in China -- Sinosauropteryx.
The feathers can be seen in the dark line running along the specimen's back.
Image: Mick Ellison, AMNH [larger view]
There is a lot of controversy among scientists regarding when modern birds first appeared. The current fossil record suggests that modern birds appeared approximately 60-65 million years ago when the other lineages of dinosaurs (along with at least half of all terrestrial…