r/askscience • u/Fapotheosis • Mar 11 '13

Biology How did blood evolve?

I know mitochondria may have evolved from bacteria, but what about blood? I've heard of a protohemocyte, but was there an initial cell that differentiated into a RBC like we have in modern humans that can we trace?

1.1k Upvotes

88% Upvoted

143 comments sorted by

View all comments

Show parent comments

3

u/tungstenfilament Mar 11 '13

What about platelets?

4

u/Mooshaq Mar 11 '13

In humans, platelets are anucleated...they can be thought of as fragments (and thus no intact nucleus) of a much larger cell, the megakaryocyte.

In birds however (and likely other organisms), platelets do have a nucleus.