Evolution Flashcards Preview

Biology > Evolution > Flashcards

Flashcards in Evolution Deck (53):
1

Evolution

The change in the genes of a population on Earth over time

2

Microevolution

The changes in one gene pool of a population over generations

3

Macroevolution

Refers to speciation, the formation of an entirely new species

4

Population

Consists of all the members of one species in one place
Ex: All lions on Masai plain in Kenya

5

Evidence of Evolution

Fossil Record, Comparative Anatomy, Comparative Biochemistry, Comparative Embryology, Molecular Biology, Biogeography

6

Types of Natural Selection

Stabilizing Selection
Disruptive/Diversifying Selection
Directional Selection

7

Stabilizing Selection

Favors more common intermediate forms & eliminates numbers of extremes

8

Diversifying or Disruptive Selection

Increases numbers of extreme types in a population

9

Directional Selection

Changing environmental conditions

10

Sources of Variation in a Population

Mutation, Gene Flow, Genetic Drift - Bottleneck effect & Founder Effect

11

Population Stability:
Hardy-Weinberg Equilibrium

Developed a theorem describing a stable, non-evolving environment - allelic frequency does not change

12

Species

A population whose members have the potential to interbreed in nature & produce viable, fertile offspring

13

Isolation

Geographic Isolation, Polyploidy, Habitat Isolation, Behavioral Isolation, Temporal Isolation, Reproductive Isolation

14

Patterns of Evolution

Divergent Evolution, Convergent Evolution, Parallel Evolution, Coevolution, Adaptive Radiation

15

Divergent Evolution

When population gets isolated from rest of species
Homologous struture

16

Convergent Evolution

Unrelated species occupy same species
Analogous Structures

17

Parallel Evolution

Two related species, similar evolutionary adaptions after divergence from common ancestor

18

Coevolution

Two interacting species with mutual evolutionary set of adaptions

19

Adaptive Radiations

Emergence of numerous species in same environment from common ancestor
14 finches in Galapagos Islands

20

Theories About Evolution

Gradualism, Punctuated Equilibrium, Spontaneous Generation

21

Heterotroph Hypothesis

Theory that the first cells on Earth were anaerobic, heterotrophic prokaryotes

22

Modifications; animals to land

Lungs, skin, limbs, shell, mechanism for internal fertilization

23

Modifications; plants to land

Roots, vascular tissue, waxy molecule, seeds, supporting cells

24

Permian Mass Extinction

Volcanic eruptions, now Siberia
Eruptions emitted CO2 into atmosphere - global climate increased 6 degrees

25

Cretaceous Mass Extinction

10km wide asteroid crashed into Mexico
Huge cloud of debris blocked sunlight for months
Extinction of many marine & land animals + all dinosaurs, excluding birds

26

Important Concepts of Evolution

Evo. is not always a slow process
Evo. does not occur at same rate in all organisms
Evo. does not always cause organisms to become more complex
Evo. occurs in populations, not individuals
Evo. is directed by changes in the environment

27

Fossil Record

Reveals existence of species that have become extinct or have evolved into other species

28

Comparative Anatomy

Organisms that have similar anatomical structures are related to each other & share a common ancestor

29

Homologous Structures

Same internal bone structure, function of each varies

30

Analogous Structures

Same function but not the same underlying structure

31

Vestigal Structure

Structures that are remnants of an earlier active structure, such as appendix
Evidence that animals have evolved

32

Comparative Biochemistry

Organisms that have a common ancestor will have common biochemical pathways

33

Comparative Embryology

Animals that have evolved from a common ancestor go through similar stages in their embryonic development

34

Molecular Biology

Comparison of the amino acid sequence of cytochrome c among different organisms shows which are most closely related

35

Biogeography

Supercontinent Pangea separated into seven continents

36

Industrial Melanism

Darkening due to industrialization

37

Mutation (Evolution)

Changes in genetic material & are the raw material for evolutionary change

38

Genetic Drift

Change in the gene pool due to chance

39

The Bottleneck Effect

Genetic Drift
Natural disasters reduce size of population non-selectively, resulting in loss of genetic variation

40

Founder Effect

Genetic Drift
Small population breaks away from larger to colonize new area
Rare alleles may be under or overrepresented

41

Gene Flow

Movement of alleles into or out of a population

42

Hardy-Weinberg Characteristics of a Stable Population

Pop. must be very large
Pop, must be isolated
Must be no mutations in the pop.
Mating must be random
Must be no natural selection

43

Sources of Variation in a Population

Mutation, Genetic Drift (Bottleneck + Founder Effect), Gene Flow

44

Geographic Isolation

When species are separated

45

Polyploidy

Mutation that results from errors during meiosis
Can only breed with polyploid organisms

46

Habitat Isolation

When 2 organisms live in the same area but encounter each other rarely

47

Behavioral Isolation

When 2 animals become isolated from each other because of some change in behavior by one member or group

48

Temporal Isolation

Time
Some plant flower in cooler part of season while other plants flowers in warmer part of growing season

49

Reproductive Isolation

Closely related species unable to mate because of anatomical incompatibility

50

Theory of Endosymbiosis

Cell organelles, like mitochondria, were once tiny, free-living prokaryotic organisms that took up permanent residence inside larger prokaryotic cells

51

Cambrian Explosion

Period of time when every major phylum of animal appeared

52

Autotrophs

Organisms that make their own food

53

Heterotrophs

Organisms that must take in all their nutrients