Megachihuahua said:
Posted by Ifrit:
"Actually, if you had read troodon's link, you'd have noticed that it suggests that scutes derived from feathers, not the other way around. "
"Scutes are not all identical, they can change, and feathers may have evolved from them."
Where did scutes come from?
Feathers
Where did feathers come from?
Scutes
The thread in question is
here in case anyone was curious.
Megachihuahua, if you would read the link you would see what is being said. The researchers, Zou, Niswander, and Alan Brush, (incidentally, Brush opposes dinosaurian ancestry for birds) performed an experiment where they inserted a virus which inhibited the expression of a certain protein into the embryos of chickens. What they found is, when this protein is inhibited, the scutes on the legs of the chickens grow into feathers.
Now, what does this tell us? It tells us that birds have the genes necessary to grow feathers on their feet but they also have one or more genes that produce a protein which prevents this from happening. This protein causes the feet to grow scutes instead of feathers (which are biochemically very similar).
Putting this into context with evolution, the researchers toyed with the possibility that feathers are inherant in archosaurs. That is, the most recent common ancestors for all archosaurs was feathery. If this were the case then the scutes we see in impressions of dinosaur skin would have evolved from feathers with the help of a protein very similar to that found in the chicken. If feathers are not inherant in archosaurs, then what happened was feathers first evolved from reptilian scutes and then reversed in some parts of bird anatomy (such as the feet) back into scutes.
So, actually, not only is it possible for feathers to have evolved into scutes, it is also possible that scutes evolved into feathers and feathers back into scutes. It is not a contradiction.
