[juletide]

Actually, recent research indicates that these two species began differentiating themselves a long time ago, but their lineages have since converged: they now interbreed freely and there's no reliable way to tell the two species apart: https://twitter.com/dlslager/status/1072353359041085440

It's been really interesting to talk to birders I trust about this. The rough consensus is, most people think they're the same species and will get merged back together soon, but some are very attached to the distinction between the two, haha.

Birds are so cool! I think it's fascinating that we're still learning new things about this stuff all the time.

[Tiktaalik]

Hm the story from the posted tweet makes sense to me. Damn that is really cool.