Chapter 18: Evolution Origins

Question 1

Theory

Answer 1

an explanation of collected data and facts

Question 2

Darwin & Wallace

Answer 2

Independently developed the idea of natural selection

Question 3

immutability

Answer 3

Things not changing

Question 4

Natural selection

Answer 4

the process by which a selective force causes individuals in a pop. to survive & reproduce to a greater degree than others,
Happens to individuals
Leads to adaptive evolution & evolutionary change.

Question 5

Fitness

Answer 5

the level of ability to survive and reproduce

Question 6

Evolution

Answer 6

A change in genotype frequencies in a population over time.

Happens to populations

Question 7

Natural selection standards

Answer 7

1. Genetic variation (mutation, sexual reproduction)
2. Selective Force (alteration in background, parasite presence, etc.)
3. This causes differential survival that leads to differential reproduction. That some individuals are more successful at reproduction for a reason.
4. Leads to genotype frequency alterations in a population.

Question 8

Adaptation

Answer 8

any trait that makes the organism more likely to survive/reproduce
Improves fitness

Question 9

Fecundity

Answer 9

Helps measure reproductive success by counting the number of surviving offspring

Question 10

Trait adaptiveness

Answer 10

Whether or not a trait is adaptive, depends on the environment the organism finds itself in.

Question 11

Divergent evolution

Answer 11

When two species (or more) evolve from a common ancestor.

Question 12

Convergent evolution

Answer 12

Similar conditions can cause the evolution of similar traits – even in unrelated organisms
Ex. Long mouths

Question 13

Evidence of evolution

Answer 13

Fossils
Anatomy & Embryology
Biogeography
Molecular Biology

Question 14

Misconceptions of evolution

Answer 14

Evolution is ‘just a theory’
Individuals evolve
Evolution explains the origins of life
Organisms evolve on purpose

Question 15

Homologous structures

Answer 15

structures that have similar parts due to shared common ancestry, which may or may not have similar functions.
Ex. Arms in humans and birds

Question 16

Vestigial structures

Answer 16

Structures that have no apparent function and are likely due to evolution from an ancestor that had a function for that structure.

Question 17

Microevolution

Answer 17

Changes within a species

Ex. Pocket mouse coat evolution

Question 18

Macroevolution

Answer 18

Formation of a new species from pre-existing species.

Ex: Modern dog species from ancestral wolf species

Question 19

Biological species

Answer 19

Population whose members can interbreed in nature & produce fertile offspring.

Question 20

Morphological species

Answer 20

defines species by physical traits; doesn’t require mating

Question 21

Ecological species

Answer 21

defines species by their role within the environment

Question 22

Phylogenetic species

Answer 22

any group of organisms that have shared common ancestry, also may use morphology (physical traits)

Question 23

Medical/micro species

Answer 23

Designated by biochemical, other phenotypic criteria & DNA relatedness, which groups strains on the basis of their overall genetic similarity.

Question 24

Speciation

Answer 24

When one group of organisms becomes isolated and evolves enough to become their own species.

Question 25

Allopatric speciation

Answer 25

When two populations are physically separated
Form of geographic isolation
Happens gradually

Question 26

Sympatric speciation

Answer 26

Organisms become species through adaptation to different parts of the geographic space
Despite same behavior/organism, different mating behaviors can develop bc of selective factors

Question 27

Reproductive isolation

Answer 27

Happens when two populations are no longer able to reproduce with each other
Causes rapid speciation
Broken up into 2 barriers: prezygotic and postzygotic

Question 28

Prezygotic barrier

Answer 28

Mating behavioral diff.
Breeding @ diff. times
Live in diff. habitats
Mechanical and gametic isolation

Question 29

Mechanical isolation

Answer 29

Form of pre zygotic reproductive isolation

Ex. mating structures are not compatible

Question 30

Gametic isolation

Answer 30

Gametes unable to join

Form of pre zygotic reproductive isolation

Question 31

Post zygotic barriers

Answer 31

Hybrids occur: these offspring between populations cannot survive or are not able to reproduce

Question 32

Hybrid zones

Answer 32

Regions in which two species have the opportunity to meet, mate, and produce some offspring
Types:
Reinforcement
Fusion
Stability

Question 33

Reinforcement

Answer 33

When hybrids are less fit (don’t survive or reproduce well) than parental species – maintains species

Question 34

Fusion

Answer 34

When hybrids are more fit than parental species causing two species to fuse into one

Question 35

Stability

Answer 35

When hybrids continue to be produced and are maintained

Question 36

Geographic isolation

Answer 36

Large geographic formations isolating populations, like a mountain
Includes allopathic speciation
May contribute to reproductive isolation

Question 37

Abiotic factors

Answer 37

Can act as a selective factor in survival

Ex. Air, soil, temp

Question 38

Biogeography

Answer 38

How living organisms are positioned in geological spaces

Question 39

Molecular Biology

Answer 39

All living things have the same DNA molecule & undergo protein synthesis.

Question 40

Anatomy & embryology

Answer 40

Shared and conserved embryological development