The Horse, Domesticated!

[Catherine]

Quote:'Horses' used to have 4-5 toes on each foot until they evolved to just one. I *think* developing embryos may also still have 4-5 toes until they reduce back up the leg, kinda like how we still have gill slits and tails as embryos. Evolution is fascinating.

I think you are right. A lot of developing embryos have vestigial parts that do not fully develop. I know humans have the beginnings of gills at an early stage, but they do not develop.

I think some relationships between species are really only clear if you look at the embryos.