Question

4. What information would allow you to distinguish between homologous vs. analogous (AKA homoplastic) traits, or to decide whether similarities between taxa likely arose via convergent evolution? Be able to do this from descriptions of traits and/or phylogenetic information.

Answer 1

Answer:

Homologies - phenotypic and genetic similarities due to shared ancestry

Analogies (homoplastic) - similarities between two species due to convergent evolution instead of descent from a common ancestor with the same trait

In general, organisms that share very similar morphologies or similar DNA sequences are likely to be more closely related than organisms with vastly different structures or sequences. In some cases, however, the morphological divergence between related species can be great and their genetic divergence small (or vice versa).

(plants very different, bc diverged 50 mil years ago)

If internal anatomy, physiology, and reproductive systems are very dissimilar, probably analogous.

The more elements that are similar in two complex structures, the more likely it is that the structures evolved from a common ancestor. If genes in two organisms share many portions of their nucleotide sequences, it is likely that the genes are homologous.: