Chapter 27.2 Evidence of Evolution

Question 1

Homologous Structures

Answer 1

Same function and same basic structure, indicating a common ancestor

Question 2

Convergent Evolution

Answer 2

Arriving at the same solution separately (no common ancestor)

Question 3

Analogous Structures

Answer 3

Same basic function but different origins

Question 4

Vestigial Structures

Answer 4

Anatomical structures fully functional in one group and reduced or nonfunctional in another
Ex: Modern whales have a pelvic girdle and hind leg bones
Ex: “Gill slits” in chicken embryo

Question 5

Developmental Pathways

Answer 5

Because they share the same instruction set (genes) as their ancestors, similar features develop in similar ways
All vertebrates have a post-anal tail and pharyngeal pouches
Early vertebrate embryos look similar

Question 6

Biochemical evidence

Answer 6

All organisms use same basic biochemical molecules
DNA– 64 codons = 20 amino acids, start & stop codons
ATP
Nearly identical enzymes and proteins
Many developmental genes are shared
Closely related organisms share more molecules in common

Question 7

What are the 3 observations of selection?

Answer 7

1. Artificial Selection (domestication & agriculture)
2. Multiple alleles for a particular gene exist (variation)
3. Interesting or useful characteristics are selected