fossil record
jwhitfield | February 2, 2009We left Darwin in a troubled frame of mind. The fossil record seemed to offer little support to his theory (then again, it offered little support to any other theory). By the time we reach the end of chapter 10, 'On the geological succession of organic beings', he's feeling far more chipper:
"[A]ll the chief laws of palaeontology plainly proclaim, as it seems to me, that species have been produced by ordinary generation: old forms having been supplanted by new and improved forms of life, produced by the laws of variation still acting round us, and preserved by Natural Selection."
What…
jwhitfield | January 31, 2009Thomas Kuhn -- the one philosopher of science that even ignorami like me have heard of -- said that during periods of 'normal science', researchers only take on problems that they know they can solve. 'Paradigm' is an overused word, but it's a measure of the paradigm-shifting nature of the Origin that in much of it, such as in chapter 9 'On the imperfection of the geological record', Darwin flies blind.
This creates almost as much trouble for the reader as it does for Darwin, as we saw in the previous chapter. The less you can explain, the more you need to describe; where Darwin has cracked a…
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…