Evolution In Process

1
Evolution In Process

• pp. 289- 292

2
Evidence of Evolution

• There are many different types of evidence for
  evolution
• Homologous/Analogous Structures
• Vestigial Structures
• Similarities in Embryology
• Similarities in Macromolecules.

3
Homologous Structures

• Homologous structures are features that
  originated in a shared ancestor.
• Ex. Forelimbs of the penguin, alligator, bat, and
  human.

4
Analogous Structure

• Analogous structures serve identical functions,
  and they look somewhat alike.
• Ex. Wings of a hummingbird and hummingbird moth
  they serve similar functions, but differ in
  structure and come from different embryological
  structures.

5
Vestigial Structures

• Vestigial structures are features that were
  useful to an ancestor, but they are not useful to
  the modern ancestor that has them.
• Ex. Tailbone in humans is similar to the
  functional tails of other vertebrates.

6
Similarities in Embryology

• Embryos of vertebrates are similar to each other.
  As development continues, the similarities will
  fade. However, the more similarities at later
  stages give clues to common ancestry.

7
Similarities in Macromolecules

• Similar amino acids in hemoglobin give clues to
  common ancestry.
• Ex. Humans and Gorillas differ by 1 amino acid
  Humans and frogs differ by 67 amino acids.

8
Patterns of Evolution

• Species can change in several ways.
• Coevolution
• Convergent Evolution
• Divergent Evolution

9
Coevolution

• Coevolution is the change of two or more species
  in close association w/ each other.
• Ex. Long-nosed fruit bat and flowers they feed on.

10
Convergent Evolution

• Convergent evolution occurs when the environment
  selects similar phenotypes, even though ancestral
  types were different from each other.
• Ex. Sharks and Porpoises.

11
Divergent Evolution

• Divergent evolution occurs when two or more
  related populations or species become more and
  more dissimilar usually due to different
  habitats.
• Ex. Different breeds of dogs.