It is fundamental to the methodology of science that hypotheses are proposed and tested. The human face of science surfaces when researchers enthusiastically endorse false positives, when hypothesis testing is less than rigorous, and when false dichotomies are proposed (i.e. if hypothesis B is falsified, hypothesis A is declared to be verified). The science of origins is well-supplied with examples of hypotheses that were once widely accepted as valid, but which are now discredited. A significant example has recently become apparent and is the theme of this blog. In 2009, Zhang et al. considered integumentary filaments of the theropod dinosaur Sinosauropteryx, knowing that Lingham-Soliar and colleagues had proposed that dino-fuzz filaments are structural collagen fibres released by processes of decay. The work reported that “melanosomes (colour-bearing organelles) are not only preserved in the pennaceous feathers of early birds, but also in an identical manner in integumentary filaments of non-avian dinosaurs”. This led Zhang et al. to conclude that the collagen fibre interpretation has been falsified and that the integumentary filaments were proto-feathers. In the summary provided by the editors of Nature:
“But it has been suggested that some of the structures that are not obviously feathers might actually be strands of collagen from under the skin. Zhang et al. refute this notion by demonstrating the presence in these structures of melanosomes – the characteristic bodies that give feathers their colours. Not only do they show that the feather-like structures of dinosaurs such as Sinosauropteryx really are akin to feathers, but also they can speculate in an informed way about their colour – which it seems was reddish brown or ginger.”
[snip]
For more, go here.