Evolution Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Evolution

A

change in allele frequencies in a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Microevolution vs. Macroevolution

A

changes in a single gene pool versus appearances of major evolutionary development or new species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Anagenesis or Phyletic Evolution

A

occurs when one species replaces another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cladogenesis or Branching Evolution

A

occurs when a new species branches out from a parent species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Evidence for Evolution: The Fossil Record

A

Paleontology reveals the existence of species that have become extinct or have evolved into other species. Also, scientists discovered transitional forms that turn into modern animals. Radioactive aging and half-lives are used to age things.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Evidence for Evolution: Comparative Anatomy

A

Homologous, Vestigial and Analogous structures contribute to the understanding of anatomical structures and relationships.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Homologous Structures

A

Structures that share bone structure but vary in function. Ex. wing of bat, lateral fin of whale, and human arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Analogous Structures

A

Structures that have the same function although the similarity is superficial. Ex. bat wings and fly wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Vestigial Structures

A

Structures that do not sere a function although they are still around. Ex. pelvic bone of snake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Comparative Biochemistry

A

Organisms with a common ancestor have common biochemical pathways. The more closely related organisms are the more similar their biochemistry is. Explains testing on animals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Comparative Embryology

A

Organisms with a common ancestors go through similar stages in their embryonic development, All vertebrate embryos go through stages in which they have gills.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Molecular Biology

A

All aerobic organisms contain cells that carry out aerobic respiration and contain the polypeptide cytochrome C. Comparing this polypeptide shows which organisms are most closely related.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Biogeography

A

Continental drift states that about 200 m.y.a. the continents were locked into Pangea that separated 150 m.y.a.. Studying geographic distribution of living organisms and fossils confirms the continental first theory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Aristotle - 1

A

The Scala Nature stated that all life forms can be arranged on a ladder of increasing complexity each with their own rung of which humans are at the top. The species are permanent and do not evolve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Carolus Linnaeus - 2

A

Specialized in taxonomy and named/classified organisms. He developed the naming system called the binomial nomenclature. In this system every organisms has a name consisting of a genus and species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cuvier - 3

A

Studied fossils and realized that each stratum of Earth is characterized by different fossils. He believed that a series of catastrophes were responsible for the changes in the organisms on Earth. He oppose evolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

James Hutton - 4

A

The theory of gradualism stated that Earth had been molded by gradual changes not violent, quick ones. The effects of wind, weather and geologic changes were those that creating canyons and ranges. His theory came from the idea that the Earth had a long history.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Lyell - 5

A

Geologist that stated that geological changes result from slow, continuous actions. He believed the Earth was older than 6,000 years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Lamarck - 5

A

Contemporary of Darwin who developed theories of evolution. His theory relies on the ideas of inheritance of acquired characteristics and use and disuse. He stated that individual organisms change in response in their environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Wallace - 6

A

A naturalist author that discussed the idea of natural selection, identical to Darwin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Darwin - 7

A

Naturalist and author that worked out the theory of natural selection and descent with modification as the mechanism for how populations evolve. On the Origin of Species was published about his work.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Darwin’s Theory of Natural Selection

A
  • Populations grow exponentially and overpopulate to deplete resources.
  • Overpopulation results in competition and a struggle for existence.
  • In any population there is variation and an unequal ability of individuals to survive and reproduce.
  • Only best-fit individuals survive and get to pass on their traits
  • Evolution occurs as advantageous traits accumulate in the population.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How insects become resistant?

A

Some insects are resistant to a particular chemical insecticide and have a selective advantage. Over time, the proportion of individuals with longer necks increase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Five Types of Selection

A

stabilizing, diversifying, directional, sexual, and artificial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Stabilizing Selection

A

Eliminates the extremes and favors the more common immediate forms. In humans birth weight in the 6-8 pound range. In starlings, birds with 5 eggs have more young survive than birds with more.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Disruptive/Diversifying Selection

A

Increases the extreme types in a population at the expense of the intermediate forms. Results in balanced polymorphism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Balanced Polymorphism

A

one population is divided into two distinct types; over a great length of time this may result in the formation of two new species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Directional Selection

A

one phenotype replaces another in the gene pool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Directional Selection: Peppered Moths

A

Until 1845, most peppered moths were light and few were dark. Due to the pollution in the industrial regions dark color frequency increased because they could camouflage better.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Directional Selection: Antibiotics

A

Bacteria appeared that were resistant to antibiotics and are transferred through plasmids which can spread and cause antibiotic resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Sexual Selection

A

Selection based on secondary sexual characteristics related to competing for and attracting mates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Sexual Dimorphism

A

difference in appearance between males and females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Artificial Selection

A

Humans breed plants and animals with desired traits as breeding stock.

34
Q

Balanced Polymorphism

A

The presence of two or more phenotypically distinct forms of a trait in a single population of a species. Each morph is better adapted in a different area but both varieties continue to exist.

35
Q

Geographic Variation

A

Two different varieties of rabbit continue to exist in two different regions. Rabbits living in the northern snow have white coats and short ears to conserve heat. Rabbits in the southern heat have mottled fur and long ears. This is the north-south cline.

36
Q

Cline

A

graded variation in the phenotype of an organism

37
Q

Sexual Reproduction

A

Provides variation due to the shuffling and recombination of alleles during meiosis and fertilization.

38
Q

Independent Assortment of Chromosomes

A

during metaphase I, this results in recombination of unlinked genes

39
Q

Crossing-Over

A

the exchange of homologous chromosomes and occurs during meiosis I; it produces individual chromosomes combine genes inherited from two parents; in humans 2 or 3 events occur

40
Q

Random Fertilization

A

one ovum by one sperm out of millions results in enormous variety among the offspring

41
Q

Outbreeding

A

mating of organisms within one species that are not closely related; maintains variation within a species and a strong gene pool; inbreeding causes detrimental recessive traits to build up

42
Q

Diploidy

A

the 2n condition maintains/shelters a hidden pool of alleles that may not be suitable under the present conditions but that could be advantageous when conditions change in the future

43
Q

Heterozygous Advantage

A

phenomenon in which a hybrid individual is selected for because it has better reproductive success ; this maintains multiple alleles in a population; ex. Sickle Cell Anemia in the West Nile

44
Q

Frequency-Dependent Selection or the Minority Advantage

A

decreases the frequency of more common phenotypes and increases the frequency of the less common ones; ex. search image

45
Q

Search Image

A

A standard representation of prey that predators have in their mind. The most common type will be preyed upon disproportionately while the less common individuals will be preyed upon less.

46
Q

Evolutionary Neutral Traits

A

Traits that seem to have no selective value. Examples are blood type and fingerprint variation.

47
Q

Causes of Evolution: Genetic Drift

A

A change in the gene pool due to chance. It is a fluctuation in frequency of alleles from one generation to another that is unpredictable.

48
Q

Genetic Drift: Bottleneck Effect

A

Natural disasters such as fire, earthquake, and flood reduce the size of a population unselectively resulting in the loss of genetic variation. The resulting population is much smaller and not representative of the original one. Ex. Tay-Sachs disease among Eastern European Jews by Jews in the Middle Ages.

49
Q

Genetic Drift: The Founder Effect

A

When a small population breaks away from a larger one to colonize a new area, it is most likely not genetically representative of the original larger population. Rare alleles can be overrepresented. Ex. polydactyly in the Old Order of Amish of Lancaster.

50
Q

Gene Flow

A

The movement of alleles into or out of a population. It can occur as a result of the migration of fertile individuals or gametes between populations. Ex. pollen

51
Q

Mutations

A

Changes in genetic material and are the raw material for evolutionary change. They increase diversity. A single point mutation can introduce a new allele into a population.

52
Q

Nonrandom Mating

A

Individuals choose their mates for a specific reason. The selection of a mate serves to eliminate the less-fit individuals.

53
Q

Natural Selection

A

Individuals who are better adapted to a particular environment exhibit better reproductive success. They have more offspring to survive and pass their genes on to more offspring.

54
Q

Stabilizing Factors of Hardy-Weinberg Equilibrium

A
  1. The population must be very large.
  2. The population must be isolated from other populations.
  3. There must be no mutations in the population.
  4. Mating must be random.
  5. No natural selection.
55
Q

Hardy-Weinberg Equation

A

Enables us to calculate frequencies of alleles in a population. - p^2 + 2pq + q^2 = 1 - and - p + q = 1. P represents the dominant allele and q represents the recessive allele.

56
Q

Species

A

population whose members have the potential to interbreed in nature and provide viable, fertile offspring

57
Q

Reproductive Isolation

A

Terms by which a species in defined. One group of genes becomes isolated from another and begin a separate evolutionary history. Once separated and with enough time they may become two different species.

58
Q

Speciation

A

anything that fragments a population and isolates small groups of individuals may cause this

59
Q

Allopatric Speciation

A

caused by geographic isolation (separation by mountain ranges, canyons, rivers, lakes, glaciers, altitude or longitude)

60
Q

Sympatric Speciation

A

no caused by geographic isolation; polyploidy, habitat isolation, behavioral isolation, temporal isolation, and reproductive isolation

61
Q

Polyploidy

A

condition where a cell has more than two complete sets of chromosomes; it can occur through breeding or naturally; nondisjunction can cause this; plants that are polyploidy cannot breed with those that are not polyploidy

62
Q

Habitat Isolation

A

two organisms live in the same area but rarely encounter each other; ex, one snake in water the other on land

63
Q

Behavioral Isolation

A

Elaborate mating rituals can be disturbed. For example, Sticklebacks are small salt water fish that change color and develop a red underbelly in response to sunlight. This starts a dance that does not occur if these steps are interrupted.

64
Q

Temporal Isolation

A

Temporal refers to time. A flowering plant colonizes a region with areas that are warm and sunny and areas that are cold and shady. The flower becomes sexually mature at different times.

65
Q

Reproductive Isolation

A

Prezygotic and postzygotic barriers; Differences in the structure of genitalia and difference in flower shape which prevent fertilization.

66
Q

Prezygotic Barrier

A

Things that prevent mating. Ex. a small male dog and a large female dog

67
Q

Postzygotic Barrier

A

Things that prevent production of fertile offspring once mating occurs. Ex. nonviable zygote.

68
Q

Divergent Evolution

A

A population becomes isolated from the rest of the species, becomes exposed to new selective pressures and evolves into a new species. Allopatric and sympatric isolations.

69
Q

Convergent Evolution

A

An unrelated species occupy the same environment and are subject to the same selective pressures and show similar adaptations. Ex. the whale’s appearance which matches the fish

70
Q

Parallel Evolution

A

Describes two related species that have made similar evolutionary adaptations after their divergence from a common ancestor. Ex. marsupial mammals of Australia and the placental mammals of North America

71
Q

Coevolution

A

The reciprocal evolutionary set of adaptations of two interacting species. All predator-prey relationships are examples and the relationship between the monarch butterfly and the milkweed plant is another.

72
Q

Adaptive Radiation

A

The emergence of numerous species from a common ancestor introduced into an environment. Each newly emerging form specializes to fill an ecological niche.

73
Q

Gradualism

A

The theory that organisms descend form a common ancestor gradually, over a long period of time, in a linear or branching fashion. According to this theory, fossils exist as evidence of every stage in the evolution of every species with no missing links. The fossil record is at odds because they rarely find transitional forms or missing links.

74
Q

Punctuated Equilibrium: Stephen J. Gould and Niles Eldridge

A

Proposed that new species appear suddenly after long periods of stasis. A new species changes most as it buds from a parent species then changes little for the rest of its existence.

75
Q

Allopatric Model

A

A new species arises in a different place and expands its range, outcompeting and replacing the ancestral species.

76
Q

Ancient Atmosphere

A

CH4, NH3, CO, Co2, N2 and H2O were abundant but there was no free O2. There was intense lightening and ultraviolet radiation that penetrated the primitive atmosphere, providing energy for chemical reactions.

77
Q

A. I. Oparin and J. B. S. Haldane

A

In the 1920s, hypothesize separately that under the conditions of early Earth, organic molecules could form. Without corrosively reactive molecular oxygen present to react with and degrade them, organic molecules could form and remain.

78
Q

Stanley Miller and Harold Urey

A

In the 1950s, tested (using electricity to mimic lightening and UV light) the Oparin-Haldane hypothesized and proved that almost any energy source would have converted the molecules in the early atmosphere to organic molecules like amino acids.

79
Q

Sidney Fox

A

In recent years, carried out experiences similar to Miller and Urey. He was able to produce membrane bound, cell-like structures he called proteinoid microspheres.

80
Q

First Cells on Earth

A

3.5 m.y.a. ;anerobic heterotrophic prokaryotes; absorbed organic molecules from the surrounding primordial soup to use a nutrient sources

81
Q

Endosymbiotic Theory

A

Mitochondria and Chloroplasts were one free living prokaryotes that took residence in other prokaryotes (phagocytosis) ; this mutualistic relationship worked so well that it became permanent

82
Q

Evidence of Endosymbiosis for Mitochondria and Chloroplasts

A
  • have their own DNA
  • DNY is more like prokaryotic DNA than eukaryotic DNA as it is not wrapped with histones
  • Organelles have double membranes: the inner belong to the host plasma membrane