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BI101 > Exam 3 Review (11-15) > Flashcards

Exam 3 Review (11-15) Flashcards

1
Q

Biological evolution

A

a change in the characteristics of a biological population over the course of generations

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2
Q

Macro evolution

A

Accumulation of microevolutionary changes that result in a new species

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3
Q

Micro evolution

A

Changes within a population

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4
Q

Natural selection (in terms of a process)

A

the process by which populations adapt to their changing environment

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5
Q

Scientific theory

A

substantial statement that is the current best explanation of how the universe works supported by numerous lines of evidence

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6
Q

Theory of evolution

A

all species on Earth today are descended from a single common ancestor, and they all represent millions of years of accumulated microevolutionary changes

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7
Q

Common descent

A

The part of the theory of evolution that all species have a single common ancestor

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8
Q

Other hypotheses for the origin of life

A

a) static model: species arise separately and do not change over time in the past 10,000 years
b) transformation hypothesis: species arise separately and change over time but no new species have arisen
c) separate types: each group of species has a separate common ancestor

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9
Q

Homology

A

similarities between species in anatomy, behavior, and genes

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10
Q

Convergent evolution

A

development of similar structures in unrelated organisms with similar lifestyles (eg. birds and bats have wings)

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11
Q

Vestigal traits

A

Nonfunctional or reduced features, eg. functionless wings on ostriches

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12
Q

Anatomical homology (convergent evolution and vestigal traits)

A

organisms that look different have similar structures

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13
Q

Developmental homology

A

similarities in the process of development from zygote to adult

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14
Q

Evidence for common descent

A

Anatomical homology, developmental homologies, molecular homology, biogeography, and the fossil record

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15
Q

Molecular homology

A

DNA homology
Similarities in DNA in different species suggest a common ancestor with that sequence.
Eg. humans and chimpanzees have 99.01% similar DNA sequences

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16
Q

Biogeography

A

Distribution of species on Earth. Similarities between species in different areas suggest a divergence from a common ancestor

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17
Q

The fossil record

A

The remains of extinct organisms show progression from ancient to modern forms of the organism

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18
Q

Radiometric dating

A

measures radioactive decay related to daughter product released by radioactive material in a rock sample to determine the age of the rock

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19
Q

How natural selection causes evolution

A

Physical or behavioral traits that lead to increased survival or reproduction become common in a population, while less favorable traits are lost. The accumulation of these changes can result in a new species.

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20
Q

Evidence for evolution

A

Anatomical homology, vestigial traits, biogeography, homology in development/embryology, homology of DNA, the fossil record

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21
Q

how drug resistant strains of tuberculosis have evolved

A

Drug treatment kills off the bacteria that are not naturally resistant, but leaves the bacterium that are naturally resistant. Those bacteria can then continue to reproduce and pass on their resistance once the drug treatment stops, creating a new strand of bacterium that are drug resistant.

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22
Q

4 observations that lead to the inference of natural selection

A

A) Individuals within populations vary
B) some of these variations can be passed down to offspring
C) populations produce more offspring than will survive
D) survival and reproduction are not random-the organisms that survive and reproduce are better adapted

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23
Q

The modern synthesis

A

genetic principles can explain how natural selection causes evolution. The random process of gene mutation creates new variations, and natural selection then acts as a filter that selects for or against the new alleles.

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24
Q

Misconceptions about natural selection (debunked)

A

A) Natural selection cannot cause new traits to arise- rather, natural selection can only select for traits that are present in the population
B) Natural selection does not result in perfection-there are always trade offs
C) Natural selection does not lead to progression towards a goal, like chimps evolving into humans-it adapts organisms to their current environment. It does not make organisms more complex necessarily

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25
Tuberculosis
TB, mycobacterium tuberculosis bacterium that damages lung tissue by creating tubercules
26
Natural selection
one way that organisms evolve from a common ancestor, physical/behavioral traits that lead to increased survival and reproduction become common in a population, while less favorable traits are lost
27
Variation/variant
each different type of individual in a population
28
Fitness (relative)
the survival and reproduction of one variant in relation to others within the same population
29
Adaptations (relation to fitness)
traits that increase relative fitness
30
Ecology
field of biology that focuses on interactions among organisms and between organisms and the environment
31
Population
all of the individuals of a species living in a certain area
32
Features of a population
a) distribution-the spacing of individuals b) density-abundance
33
Types of distribution
a) clumped (high density in resource-rich areas, lower density elsewhere) b) uniform c) random
34
Exponential growth
Human population growth-J shaped graph where growth occurs in proportion to current total
35
Growth rate
% change in size of a population over a year, function of birth rate minus death rate
36
Demographic transition
The period of time between when death rates fall and when birth rates fall
37
Why populations (esp. humans) go through demographic transition
Less developed countries are still in demographic transition. Death rate falls because of medical advancement, but birth rates have not yet because of societal expectations
38
Carrying capacity
maximum population that can be supported indefinitely
39
Factors that affect carrying capacity
Density-dependent Density-independent
40
Density-dependent factors
population-limiting factors that increase in intensity as population increases, like limited food supplies
41
Density-independent factors
influence growth rate regardless of density: drought/temperature
42
Signs that humans have not neared carrying capacity
a) death rates continue to decline-people aren't running out of resources population growth is slowing because of lower birth rates b) we have not consumed 100% of the NPP
43
Net primary productivity
measure of all the food energy available on Earth
44
Signs that we are nearing carrying capacity
a) humans need more than just food b) every new person also creates pollution c) we rely on nonrenewable resources that will run out
45
Population crash
steep decline in population caused by too many individuals competing for too few resources
46
Population cycle
repeated booms and busts in number
47
Demographic momentum
Lag between when birth rates fall and population growth actually stops
48
Population pyramid
summary of numbers and proportions of each sex and age group
49
Extinction
The complete loss of a species or subspecies
50
Biodiversity
the entire variety of living organisms
51
mass extinction and how many
species losses that are global in scale, affect large numbers of species, and are dramatic in impact 5 so far, potential 6th
52
Background extinction rate
the rate at which species are lost through normal evolutionary processes
53
4 categories of extinction threats
1) loss/degradation of habitat 2) introduction of nonnative species 3) overexploitation 4) effects of pollution
54
Habitat fragmentation
large areas of intact natural habitat are subdivided Causes lower levels of the trophic pyramid to shrink, depriving upper levels of calories
55
Food chain
energy runs from producers to primary consumers to secondary consumers (predators)
56
Coevolution
a pair or group of species adapt to each other via natural selection Some species are not adapted to the introduced species
57
Consequences of extinction
A) Loss of resources: economic, biological, and genetic B) Predation, mutualism, and competition affected C) Energy and chemical flows affected D) Human psychological toll
58
Biological community
all organisms living together in a particular area
59
Ecological niche
each species occupies a specific role or job, each part creates a food web
60
Four types of species interactions
A) mutualism B) predation C) competition D) keystone species
61
Mutualism
interaction between two species that benefit each other eg. bees and flowering plants
62
Commensalism
one species benefits another but the other is unaffected eg. cattle and egrets
63
Predation
the survival of one species dependent on eating another eg. warblers and insects
64
Competition
two species both rely on the same resources eg. salmonella and neutral bacteria
65
Competitive exclusion
using a competitive species to take up all the resources available in an environment in order to exclude a harmful species
66
Keystone species
a species that holds together the web of life like a keystone in an archway eg. wolves in Yellowstone change elk behavior which maintains populations of hardwood trees
67
Ecosystem
all of the organisms in an area along with their non-biological environment
68
Energy flow and extinction Diversity and extinction
the amount of biomass at the producer level determines the size of the population at the highest level. Decline in diversity=decline in energy available
69
Nutrient cycling
Essential mineral nutrients move through the food web from inorganic forms to plants to primary consumers, etc. Returns to inorganic form through decomposers
70
Nitrogen and extinction
More nitrogen=more plants=more higher trophic levels Changes in the nutrient cycle affect native plants
71
Ways to save species
A) protecting habitat B) protecting small species C) conserving genetic variability
72
Protecting habitat
A) protecting the greatest number of species B) protecting habitat for critically endangered species C) decreasing rate of habitat destruction
73
Small population risks
Small populations are more vulnerable, the smaller it is, the more likely a random catastrophe would eliminate it
74
Genetic variability Effects on fitness
the sum of all the alleles and their distribution in a species Low genetic variability reduces fitness Lack of ability to adapt to changes because no individuals may possess the necessary trait
75
Heterozygote advantage
A) if each allele codes for a functional protein, a heterozygote has two functional proteins B) if one allele is deleterious, a heterozygote will have a backup
76
Genetic drift
change in the frequency of an allele that occurs simply by chance within a population Smaller population=less of an infrequent allele

BI101 (7 decks)

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