Natural Selection and Evolution - Part 7 (Week 9)

Question 1

What does natural selection do?

Answer 1

• does not create new traits
• edits/selects for traits already present in the population
• current, local environment determines which traits will be selected for/ selected against in any specific population

Question 2

What is homology?

Answer 2

• similarity resulting from common ancestry

Question 3

What are homologous structures?

Answer 3

• anatomical resemblances that represent variations on a structural theme present in a common ancestor

Question 4

What does comparative embryology reveal?

Answer 4

• reveals anatomical homologies not visible in adult organisms
  e. g. all vertebrate embryos have a post-anal tail + pharyngeal arches (gills)

Question 5

What are vestigial structures?

Answer 5

• remnants of features that served important functions in the organism’s ancestors
• genes shared among organisms inherited from a common ancestor (at a molecular level)

Question 6

What is the convergent evolution?

Answer 6

• evolution of similar/ analogous, features in distantly related groups