Unit 3: EVOLUTION

Question 1

5 agents of evolutionary change

Answer 1

-mutation
-gene flow
-genetic drift
-non-random mating
-natural selection

Question 2

Mutation

Answer 2

Introduces genetic variation into a population providing new material for evolution

Question 3

Gene flow

Answer 3

Movement of alleles between populations due to migration; increases genetic similarity between populations and introduces new alleles into populations

Question 4

Non-random mating

Answer 4

Individuals select partners based on phenotypes

Question 5

Natural selection

Answer 5

Process where some individuals have more offspring than others

Question 6

3 types of selection

Answer 6

1. Stabilizing
2. Directional
3. Disruptive

Question 7

Stabilizing selection

Answer 7

Intermediate phenotype is favoured
Eg. Medium sized bird beak allows for access to most resources in a habitat

Question 8

Directional selection

Answer 8

One extreme phenotype is favored
Eg. Giraffes long neck

Question 9

Disruptive selection

Answer 9

Both extreme phenotypes are favoured
Eg. 2 different shell patterns on a beetle carapace

Question 10

Sexual selection

Answer 10

The over production of physical traits, more than needed for survival to gain access to a female
Eg. Male birds have much more colour than female birds (duck)

Question 11

More derived

Answer 11

traits in a species that have evolved most recently

Question 12

Homologous structure

Answer 12

-Parts with similar basic structure in species, but the function may vary
Eg. Human hand vs. Whale fin
-evolved from common ancestor

Question 13

Analogous

Answer 13

-structures may look somewhat alike or different but have the same function
-do not have common ancestor
Eg. Bird wings and fly wings both made for flying

Question 14

Allopatric vs. Sympatric

Answer 14

Allopatric - When a population is physically divided (eg. river) leading to the formation of a new species
Sympatric - no physical separation of habitat, though genetic differences or behaviours occur

Question 16

Prezygotic vs. Postzygotic

Answer 16

Pre - factors that affect reproduction before the zygote is formed
Post - these mechanisms take place after the zygote is formed

Question 17

Explain how molecules of life evolved abiotically

Answer 17

Example of this:
Miller-urey experiment: made a simulation of the atmosphere using common elements of the atmosphere, and a few days later they were left with amino acids, which are the building blocks of protein and thus life. It showed that essential molecules can form from simple chemicals in the right conditions

Question 19

Ecological species concept

Answer 19

Set of organisms that exploit a single niche such as resources or habitat
Eg. Galapagos finches that look the same but one eats fruit and the other eats seeds.

Question 20

Morphological species concept

Answer 20

Set of individuals with morphological features in common - these are distinct from another species
Eg. Butterflies live in the same habitat but actual species is distinguished by wing pattern

Question 21

Biological species concept

Answer 21

Naturally interbreeding and able to produce fertile offspring 4-6% hybridization rate

Question 22

Phylogenetic species concept

Answer 22

These have unique genetic history from other species. Unique features