Biology 1001A Lecture Notes - Lecture 18: Primate, Agnatha, Carnivora

• School: Western University
• Department: Biology
• Course: Biology 1001A
• Professor: Beth Mac Dougall- Shackleton

Document Summary

Most recent common ancestor (mrca) for a given group(s), given a phylogenetic tree. Universal common descent and origin of species. Similarities due to descent from a common ancestor. Mrca occurs at nodes in a phylogenetic tree. Luca is most recent ancestor for of all living things. Wh(cid:455) the idea that (cid:862)hu(cid:373)a(cid:374)s are des(cid:272)e(cid:374)ded fro(cid:373) (cid:272)hi(cid:373)ps(cid:863) is inaccurate. We shared a (cid:272)o(cid:373)(cid:373)o(cid:374) a(cid:374)(cid:272)estor (cid:449)ith (cid:272)hi(cid:373)ps a(cid:374)d (cid:271)o(cid:374)o(cid:271)os so(cid:373)e ti(cid:373)e ago that did(cid:374)"t exactly look like humans, chimps, or bonobos rather shared some features that are common to all three groups. Wh(cid:455) so(cid:373)e traditio(cid:374)al groupi(cid:374)gs of orga(cid:374)is(cid:373)s (cid:894)(cid:862)reptiles(cid:863), (cid:862)fish(cid:863)(cid:895) do (cid:374)ot refle(cid:272)t e(cid:448)olutio(cid:374)ar(cid:455) relationships. Traditional systematics classify the reptilia taxa together but exclude birds (ie. include turtles, lizards, and crocodiles but not birds) Some reptiles are more closely related to birds than they are to other reptiles. Some fish are more closely related to us than they are to other fish. Traditional groupings do not always accurately reflect evolutionary relationships.