#14 Evolution

Question 1

Evolution

Answer 1

• a change in genetic allele frequencies in a population (not individuals) over time
• only detectable in a population
• formation of new species is a special case of evolution

the theory is falsifiable

Question 2

Darwin

Answer 2

Origin of Species (1859)

-Natural selection: unequal reproduction between types

Question 3

Modern Synthesis

Answer 3

Joins genetics and evolution into a single body of knowledge

Question 4

Microevolution

Answer 4

Short time spans

Change in allele frequencies within a population

Question 5

Macroevolution

Answer 5

Long time span

Cumulative effects of microevolutionary processes

Question 6

Support for the evolutionary theory

Answer 6

Fossil records
Biogeography
Comparative anatomy
Comparative embryology
Molecular biology
Observed natural and artificial selection

Question 7

Strata

Answer 7

Rock layers

• organisms preserved here as “sample”
• see change in historical sequence

Question 8

Biogeography

Answer 8

Geographic distribution of species

-areas separated longer, more unique collection of species

Question 9

Homology

Answer 9

Similarity that results from common ancestry

E.g. same structures change for different functions

Question 10

Vestigial organs

Answer 10

Organs with no use to organism, had use in ancestor

Question 11

Comparative embryology

Answer 11

Compare early stages of development

-early structures become vestigial or highly modified in evolutionarily “newer” organisms

Question 12

ALL organisms use

Answer 12

DNA and RNA to code for protein

Question 13

Natural selection based on

Answer 13

1. Variation among indiv. (diff phenotypes)
2. Variation is heritable (genetic)
3. Diff reproduction among phenotypes (beneficial to have variet)

Question 14

Artificial selection

Answer 14

Differential reproduction generated by human breeding

Question 15

Natural selection

Answer 15

Editing mechanism

Question 16

Four mechanisms that contribute to evolutionary change

Answer 16

1. Selection
   
   • Natural
   • Sexual
2. Mutation
3. Genetic drift
4. Gene flow

Question 17

Sexual selection

Answer 17

Caused by mating differences
- preference for showy traits
- weapons for fighting off mates
Often leads to sexual dimorphism
Traits that may help repro. may hurt survival

Question 18

Mutation

Answer 18

Spontaneous (must be in gametes)
Largely cause by chemical or ionizing radiation
Most have no effect (eye color) or are deleterious and recessive

Question 19

Genetic drift

Answer 19

Change in gene frequencies due to chance (no adv. or disadv.)
Small pop
Founder effect
Bottleneck effect

Question 20

Gene flow

Answer 20

Change in frequency due to dispersal

Introduces new alleles to pop.

Question 21

Evolution fashions imperfect organisms

Answer 21

Organisms limited by historical constraints
Selection can only EDIT existing variation
Adaptations are often compromises
Selection and chance interact