Evolution (Exam 2) Flashcards

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1
Q

Darwin

A
  • Went to Galapagos islands on world tour where he collected species and noticed the birds differed on each island.
  • observed that endemics are usually most closely related to mainland species despite environmental differences.
  • He published “on the origin of species by means of natural selection”.
  • His beliefs were influenced by fossils
  • descent with modification
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2
Q

founder effect

A

Occurs when a new population is started by only a few individuals that do not represent the gene pool of the larger source population.

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3
Q

Endemics

A

A species found in a single location, and no one else in the world, usually most closely related to nearest mainland

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4
Q

Empirical thought

A

Relies on observation to form an idea or hypothesis rather than trying to understand life from a nonphysical/spiritual point of view

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5
Q

“On the origin of species by means of natural selection”

A

A book published by Charles Darwin where he connected all the known facts of evolution. He made 2 points:

  1. Today’s organisms transcended from ancestral species
  2. Natural provided a mechanism for evolutionary change in populations

This challenged beliefs that were centuries old

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6
Q

Classical greek philosophers who opposed evolution

A

Plato: Believed in two worlds, one real world that is ideal and perfect and an illusory world that we perceive through our senses

Aristotle: Believed that all living forms could be arranged on a ladder of increasing complexity, species are permanent and “perfect”

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7
Q

Georges Cuvier

A

A french anatomists who largely developed early paleontology. He advocated catastrophism and recognized extinction was common in the history of life.

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8
Q

Catastrophism

A

Advocated by Cuvier, it is the concept that boundaries between strata in the ground were due to local flood or drought that destroyed the species present at the time. This was later repopulated with species from unaffected areas

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9
Q

Radiometric dating

A

Method used to determine absolute ages of fossils by analyzing radioactive isotopes

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10
Q

Gradualism

A

Theory that profound change results from slow, continuous processes. Advocated by James Hutton

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11
Q

James Hutton

A

A Scottish geologist who advocated gradualism, in contrast to Cuvier and catastrophism. He also proposed that diversity of land forms could be explained by mechanisms currently operating

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12
Q

Uniformitarianism

A

Theory proposed by Charles Lyell that geological processes had not changed throughout earth’s history

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13
Q

Which scientists had a big influence on Darwin and how?

A

Hutton and Lyell.
1. If geological changes are gradual, earth must be older than 6000 years old(believed age of earth at the time)

  1. Slow, subtle processes can add up to substantial change
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14
Q

Lamarck

A

First to suggest evolution/that species arent fixed, acquired traits, use/disuse

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15
Q

Linneaus

A

Classification system that assumes species are fixed

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16
Q

Ernst Mayr(general)

A

Evolutionary biologist who dissected Darwin’s theory into 3 inferences based on 5 observations

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17
Q

Darwin’s observations as described by Mayr

A
  1. Large amount of fecundity
  2. Population tend to be stable in size
  3. Resources are limited
  4. No individuals are alike, large amount variety
  5. Much variation in a population is heritable
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18
Q

3 Inferences of Darwin’s theory as dissected by Mayr

A
  1. Only some offspring from each generation survive. Reproducing more than an environment can handle creates a survival struggle
  2. Survival is not random, survival of the fittest
  3. Unequal ability of individuals to survive and reproduce will lead to a gradual change in the population, with favorable characteristics emerging
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19
Q

3 main ideas of Darwin

A
  1. Natural selection is differential success in reproduction
  2. Natural selection occurs through an interaction between the environment and the variety inherent among the individual organisms making up a population
  3. Adaptation is a product of natural selection
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20
Q

Thomas Malthus

A

Heavily influenced Darwin’s veiws on overreproduction by writing an essay contending that human suffering was the inescapable consequence of human overpopulation

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21
Q

Differential reproduction

A

Organisms with traits favored by the environment reproduce more than organisms without those traits

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22
Q

Darwinian view of life

A
  1. Diverse lifeforms have arisen by descent with modification from ancestral species
  2. The mechanism of modification has been natural selection working over time
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23
Q

Fecundity

A

tendency to produce more than the environment can support

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24
Q

Homology

A

similarities in characteristics resulting from common ancestry

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25
Q

Homologous structures

A

similar structures in different species because of common ancestry

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26
Q

Vestigial organs

A

homologous structures that have little or no importance to a current organism but was important in its ancestors

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27
Q

Convergent evolution

A

2 different species from different lineages show similar characteristics because they occupy similar environments

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28
Q

Analogous structures/species

A

Similar structures/traits resulting from convergent evolution

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29
Q

Shared derived character

A

aka synapomorphy, it is a characteristic unique to a particular clade

30
Q

shared primitive character

A

found in the clade being analyzed as well as older ones aka synpleisiomorphy

31
Q

Developmental homology

A

similarities in embryonic stages of species

32
Q

Homologous genes

A

2 genes derived from the same ancestral gene, revealing molecular details of evolutionary change

33
Q

Adaptive evolution

A

Creates new genetic variation by mutation and sexual reproduction via natural selection, producing organisms that are better fit for the environment

34
Q

Which aspect of an organism interacts with the environment?

A

the phenotype

35
Q

Red Queen mode of coevolution

A

natural selection continually operates on each species to keep up with improvements made by competing species

36
Q

Modern description of natural selection

A
  1. Allele variation results from mutation
  2. Some alleles may code for beneficial alleles
  3. Individuals with beneficial alleles are more likely to survive and contribute beneficial alleles to offspring/the gene pool
  4. Natural selection changes the allele frequencies of many genes over time, changing the population.
37
Q

Directional selection

A

When a shift in the frequency of a phenotype occurs. Common during periods of environment change or when members of a population migrate to a new habitat.

38
Q

Diversifying selection

A

Environmental conditions favor individuals at both extremes of the phenotypic range over intermediates

39
Q

Stabilizing selection

A

Favors survival of individuals with intermediate phenotypes

40
Q

Disruptive selection

A

Favors survival of two or more different genotypes that produce different phenotypes, more likely in diverse environments

41
Q

Balancing selection

A

2 or more alleles are kept in balance, maintain genetic diversity. This can happen when a heterozygote is favored or if rare individuals are favored

42
Q

Phylogeny

A

The evolutionary history of a species or group of related species. Includes divergence points of species scaled relative to time

43
Q

Conditions of hardy-weinberg equilibrium

A
  1. No mutations
  2. Random mating
  3. No natural selection
  4. Extremely large population size
  5. No gene flow
44
Q

Purpose of hardy-weinberg equilibrium?

A

To serve as a control comparison and demonstrate what no evolution looks like

45
Q

Phylogenetic species concept

A

members of the same species share a certain % of DNA

46
Q

What factors make certain organisms better fit for their environments?

A

Being able to put the most energy possible in reproducing while surviving successfully

47
Q

Parsimony

A

the phylogenetic tree with the fewest evolutionary changes is most likely correct

48
Q

Sexual dimorphism

A

Differences sexual characteristics other than reproductive organs such as size/color differences

49
Q

Intrasexual selection

A

direct competition among individuals of one sex, usually males, for mates, determines dominance

50
Q

Intersexual selection

A

Mate choice when members of one sex, usually females, are choosy in selecting members among individuals of another sex

51
Q

Smallest biological unit that can evolve over time

A

population

52
Q

What levels do natural selection and evolution occur on?

A

natural selection: individual

Evolution: Population

53
Q

Detritivores

A

decomposers that get energy from detritus(non living matter) that connect the trophic levels. consist of prokaryotes and fungi

54
Q

Rate of decomposition

A

Controlled by temperature, moisture and nutrient availability, controls rates of nutrient cycles in ecosystems

55
Q

primary production

A

amount of light energy converted to chemical energy by autotrophs during a given time period

56
Q

what determines the amount of energy in an ecosystem?

A

the extent of photosynthetic production

57
Q

Gross primary production

A

total primary production of an ecosystem

58
Q

Net primary production

A

GPP-energy used by primary producers for respiration. Expressed as energy per unit time(J/m^2 •yr) or biomass added per unit area per unit time(g/m^2 •yr). Available to consumers

59
Q

Secondary production

A

the amount of chemical energy in food converted to new biomass during a given period of time

60
Q

Production efficiency

A

The fraction of energy stored in food that is not used for respiration

PE= Net secondary production•100%/Assimilation of primary production

61
Q

Evapotranspiration

A

The profess by which water is transferred from land to the atmosphere by evaporation from soil and other surfaces and by transpiration from plants

62
Q

Atmospheric deposition

A

usable nitrogen is added to the soil by rain or dust

63
Q

Nitrogen fixation

A

Certain prokaryotes convert N2 to ammonia that can be used to synthesize nitrogenous organic compounds like amino acids, results in ammonium(ammonification)

64
Q

Nitrification

A

Oxidizing ammonium into nitrate

65
Q

Denitrification

A

When some plants and bacteria take oxygen from the nitrate and release it back into the atmosphere

66
Q

how does phosphorus exist in nature?

A

As phosphate

67
Q

How do organic materials available as nutrients become unavailable?

A

fossilization

68
Q

How do organic materials available as nutrients become inorganic materials available as nutrients and vice versa?

A

Organic to inorganic: Respiration, decomposition, excretion

Inorganic to Organic: Assimilation, photosynthesis

69
Q

How do organic material unavailable as nutrients become inorganic materials available as nutrients?

A

Erosion, burning of fossil fuels

70
Q

How do inorganic materials available as nutrients become inorganic materials unavailable as nutrients and vice versa?

A

Available to unavailable: formation of sedimentary rock

Unavailable to available: Weathering, erosion