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Flashcards in Chapter 4 Deck (99):
1

When all members of a species die

Extinction

2

the pace at which species go extinct due to gradually changing environments.
Most extinctions occur as part of this.

Background extinction rate

3


Earth has witnessed five ___________ in the last 600 million years. During these periods, many species went extinct in a short time.

mass extinctions

4

suggests that meteorites or comets caused some mass extinctions.
The debris suspended in the atmosphere after a collision dramatically changed the environment, leading to the extinction of many species.

Impact theory

5

(Earth’s shifting land masses) also might explain mass extinctions.

Plate tectonics

6

= early life
= age of dinosaurs
= era of mammals

Paleozoic
Mesozoic
Cenozoic

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= the cretaceous (K) – tertiary (T) boundary

The KT boundary

8

A layer of sediment containing high levels of iridium

The K-T boundary

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the study of interactions between biotic and abiotic elements

Ecology

10

All living components

Biotic

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Nonliving elements
• temperature, light, water, minerals, air

Abiotic

12

A group of organisms inhabiting the same area

Population

13

:an individual living thing

Organism

14

: the study of how populations interact and change in response to their environment

Population ecology

15

: the study of organismal adaptations that allow it to live in its environment

Organismal ecology

16

: interacting populations that inhabit a particular area

Community

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: the study of population interactions and how these dynamics affect community structure

Community ecology

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: the nonliving environment and all the living organisms within a certain area

Ecosystem

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: the study of energy flow and nutrient cycling in a given environment

Ecosystem ecology

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: the global ecosystem
– All of the ecosystems on the planet
– Most complex level in the ecological hierarchy • Atmosphere down to the deepest ocean depths

Biosphere

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– Immediate responses to environmental changes – May be behavioral or physical
– Short term and quickly altered

Thermoregulation

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– Longer term responses
– Reversible
– Includes thicker fur in winter (winter coat), increased or decreased metabolism, increased fat stores, etc.

Acclimation

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: the way individuals are spaced within a geographic range

Patterns of dispersal

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: individuals aggregated in patches

Clumped

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: individuals are uniformly spaced

Uniform

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: individuals are spaced in an unpredictable way

Random

27

When two (or more) species in a community rely on similar resources

Interspecific competition

28

Two species that compete for the same niche cannot coexist
-the superior competitor will exclude the weaker
-

Competitive exclusion principle

29

-Both are top predators
-hyenas have a wider

Lions and Hyenas

30

Basis for a lot of evolutionary adaptation
- really neat adaptations
-Eat and avoid being eaten

Predation

31

-Prey usually ahead of the predator evolutionarily

Life/lunch hypotheses

32

When one species lives in or on another species

Symbiotic relationship

33

(Sym rel) when one organism benefits while the other is harmed

Parasitism

34

(Sym rel) when one organism benefits but the other is not harmed in the interaction

Commensalism

35

(Sym real) when both organisms benefit

Mutualism

36

Any episode that damages or disrupts a biological community
- storms, fire, flood
-* most communities are in some stage of recovery from this

Disturbances

37

Diversity is highest at intermediate levels of disturbance

Intermediate disturbances hypothesis

38

Biodiversity has three main components

-genetic diversity
-species diversity
-ecosystem diversity

39

The loss of species also means loss of _______ and _____ diversity

Genes, genetic

40

Human ______ allows us to recognize the value of biodiversity for its own sake

Biophilia

41

Practical benefits to humans with species diversity

The enormous genetic diversity of organisms has potential for great human benefit
Drugs, economic impact of tourism, our success

42

How are we impacting the environment

Burmese pythons in Florida.

43

The cues that animals use are no longer tightly linked to true habitat quality and an _____ arises where individuals will prefer now unsuitable habitat.
-can arise for a variety of reasons including amplification of cues.

Ecological traps

44

Absorb and emit radiation in the atmosphere

Greenhouse gas

45

Current CO2 levels higher than in the past ______ years

400,000

46

Caused a dramatic rise in CO2

Industrial revolution

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= (#births – #deaths)÷population size

• Rate of increase (r)

48

is just change in a population over time
• Specifically it is change in the allele frequencies in a population over time
– So populations are always

Evolving

49

What evidence, that you know of, do we have for evolution?

– Fossils– Genetic similarity– Biogeography– Observational changes in populations (e.g. antibacterial resistance, DDT resistance in mosquitoes)– Experimental evolution– Selective breeding.
– And more

50

many species were created, then portions were destroyed and fossilized in successive catastrophes

Catastrophism

51

– Living organisms are modified as they grow
• Through use of their own bodies
• Through changing environmental pressures
– Modifications passed on to offspring
• Problem with this idea?
• If you lost your right leg in a logging accident then your kids would be born with no right leg
• All body builders’ children should be HUGE!

Inheritance of Acquired Characteristics

52

– Individuals with certain heritable traits leave relatively more offspring
– Became known as “Evolution by Natural Selection”
• Wallace got screwed
– This is what’s commonly referred to as “survival of the fittest”
• A poor approximation of the true meaning

Natural Selection

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• The most studied mechanism of evolution
• There are others – Mutation– Genetic drift
• Commonly conflated with evolution

Natural selection

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– Observation 1: Populations produce far more offspring than the environment can support
• Overproduction leads to competition
– Observation 2: Individuals in a population vary in many traits
• Successful individuals pass on their traits to offspring
– Inference: Modification in organisms is due to differential survival and reproduction
• Most fit organisms make the most babies
• Most fit organisms’ genes in greater numbers in the next generation

How natural selection developed

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Evidence of Evolution

Fossil record, missing links, biogeography, capmparitive anatomy-homologous structures-analogous structures,

56

favors individuals with an extreme value for a trait

Directional Selection:

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favors individuals at both extremes of a trait

Disruptive Selection:

58

favors individuals with the average value for a trait or culls individuals with extremes of the trait

Stabilizing Selection:

59

a group of individuals of the same species living in the same area at the same time

Population:

60

all the alleles of all the genes in all the individuals making up a population

Gene pool:

61

Gene flow: movement of alleles into or out of a population

Gene flow:

62

Structures with similar origin. Differ in design and function

Homologous structure

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Similar function. Different evolutionary history. Result of convergent evolution

Analogous structures

64

Evidence of evolution

Comparative embryology( organisms go threw nearly identical developmental stages

65

Is a sorting process. Has no specific objective(it doesn’t want to make certain species, not goal directed

Natural selection

66

Individuals struggle to acquire limited resources
Food
Territory

Competition

67

Competition for mates

Sexual selection

68

Favors individuals with an extreme value for a trait

Directional selection

69

Favors individuals at both extremes of a trait

Disruptive selection

70

Favors individuals with the average value for a trait

Stabilizing selection

71

Chance events change allele frequencies
Bottleneck effect-Over hunting
Founder effect- individuals colonies new ares

Genetic drift

72

Preference for mates that are similar

Assortative mating

73

Females are picky and choose a breeding partner

Female mate choice

74

Males compete for the attention of females

Male/male competition

75

Not just about survival of the fittest! You got to make babies

Differential survival and reproduction

76

Two closely linked species become the most dominant force in each other’s evolution. Snake ,newts
Very common in pollination interactions

Convolution

77

The sorting process that determines what characteristics are favored for mating. Selection administered by “choosier” sex(usually female)

Sexual selection

78

More flashier males mean that they are fit because they survived despite there flashy traits.”honest advertisement”

Zahavi’s hypothesis

79

Why are females typically the choosier sex?

More time invested

80

Females don’t choose mate, brightly colored, leave male with eggs, female mates with multiple males

Role reversal

81

Changes in the gene pool over successive generations
-alleles and genes

Microevolution

82

Formation of species , evolutionary novelty, diversification, mass extinction

Macroevolution

83

Accumulation of changes gradually
Transforms the species,but does not create a new one

Anagenesis

84

Splitting of a gene pool into separate pools.
Not genetic drift
*only pattern that increases the number of species

Cladogenesis

85

Current changes build on previous changes

Cumulative change

86

*mutation provides raw material.
Source of change

Evolutionary novelties

87

Deals with species and how they come about and change over time.

Macroevolution

88

The process by which new species form

Speciation

89

(Category of speciation) species form due to geographic separation

Allopatric speciation

90

(Category of speciation) species form in the geographic are.
-form due to behavioral or niche separation
-more common in plants

Sympatric speciation

91

Similar traits evolving in separate species
-long history of evolutionary isolation

Convergent evolution

92

(Tempo of speciation) species gradually diverge as they require unique adaptations

Gradualist

93

(Tempo of speciation) periods of rapid change followed by long periods of little to no change, probably more common, *data suggests this led to the formation of different animal phyla. *not mutually exclusive.

Punctuated equilibrium

94

*populations must remain isolated

Maintaining species

95

(Maintaining species) two types of barriers.
1. Mechanisms that prevent mating.-geographic isolation
2.mechanisms that prevent successful hybrids.-Hybrid inviability

1.pre-Zygotic
2.post-zygotic

96

The pattern of continuously accelerating increase of population size under ideal unregulated conditions

Exponential growth model

97

Factors that limit population size as density increases.
-predation,-parasitism,-competition

Density-dependent factors

98

Factors that limit population size regardless of density.
-climate/wether,-natural disasters, -human activities(pesticides,hunting, habitat destruction)

Density-independent factors

99

The three levels of biodiversity

-genetic diversity
-species diversity
- ecosystem diversity