Lecture 2

Question 1

What is microevolution?

Answer 1

The change in allele frequencies over time within a population

Question 2

What is macroevolution?

Answer 2

Evolution above the scale of species

Question 3

What are the alternative explanations for diversity/change/adaptation?

Answer 3

1. Evolution
2. Transformism
3. Creationism

Question 4

What does evolution explain?

Answer 4

With evolution, all species have a common origin, and change and diversity through time

Question 5

What does transformism explain?

Answer 5

With transformism, species have separate origins, and species change but don’t diversity

Question 6

What does creationism explain?

Answer 6

With creationism, many postulate separate creations of species and the immutability of species

Question 7

How is microevolution observed?

Answer 7

1. Direct observation
2. Field experiments
3. Transformation experiments

Question 8

How is macroevolution observed?

Answer 8

1. Fossil record
2. Biogeography distributions (i.e. closely related species often occur in the same or in proximate biogeographic regions - hiearchial nested relationships of species)

Question 9

What is the definition of homology?

Answer 9

A homology is a shared feature that is inherited from a common ancestor (e.g. vertebrae forelimbs, universal genetic code, embryological stages)

Question 10

What is the significance of homology?

Answer 10

Homologous structures are evidence of both evolution and the theory that organisms descended from a common ancestor

Question 11

What is the definition of a vestigial structure?

Answer 11

A vestigial structure is an anatomical features or behavior that no longer seems to have a purpose in the current form of an organism of the given species; these vestigial structures were once important in function at one point in time

Question 12

What is the significance of a vestigial structure?

Answer 12

Vestigial structures are evidence of evolution, as well as descent with modification

Question 13

What is the definition of a pseudogene?

Answer 13

A pseudogene is an imperfect duplicate/copy of a functional gene that lost some or all functionality of a complete gene (e.g. GULO pseudogene synthesizes vitamin C)

Question 14

What is the definition of a suboptimal design?

Answer 14

A suboptimal design includes features not perfect it from an engineering perspective (e.g. the crossing of the air pathway with the food pathway)

Question 15

What is the significance of a suboptimal design?

Answer 15

Suboptimal designs are evidence of descent with modification

Question 16

What is the definition of natural selection?

Answer 16

Natural selection is differential survivorship and reproduction due to a heritable trait

Question 17

What is the significance of natural selection?

Answer 17

Natural selection is one of the major forces shaping the course of evolution; it is the only evolutionary for generating adaptation in a population

Question 18

A trait is called an adaptation when what factors occur?

Answer 18

1. Improve survivorship and reproduction
2. Arose by natural selection

Question 19

What is the definition of convergence?

Answer 19

Convergent evolution is the process whereby organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments (e.g. the body plan in placental and marsupial mammals)

Question 20

What is the significance of convergence?

Answer 20

Convergence provide evidence of shared ancestry and similar biological needs (i.e. independently evolved solution to a similar problem)

Question 21

What is the definition of vicariance?

Answer 21

The geographical separation of a population resulting in a pair of closely related species

Question 22

What is the significance of vicariance?

Answer 22

Vicariance is evidence of the separation of biological lineages via continental drift

Question 23

Explain how human brachial clefts are a vestigial structure:

Answer 23

Human brachial clefts are homologous to gills - when brachial arches form in early embryonic development but fail to obliterate, brachial cysts form