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Evolution Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

Adaptation

A

A structure, behaviour, or physiological process that helps an organism survive and reproduce in its environment

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2
Q

Allopatric speciation

A

When a population is split due to some geographical barrier which prevents members of two groups from reproducing together

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3
Q

Analogous structures

A

-different structures, similar function
-organisms are NOT closely related. However, they have evolved a similar “solution” to a problem

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4
Q

Artificial selection

A

Occurs in captivity rather than a natural setting. Humans chose the traits THEY wish to see in the offspring and breed only those individuals that show the trait

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5
Q

Bottleneck effect

A

A population is greatly reduced due to a catastrophic event, resulting in certain alleles being over or under-represented

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6
Q

Directional selection

A

-favours phenotypes at one extreme or another
-causes a shift in the distribution curve
-common during times of environmental change

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7
Q

Disruptive selection

A

Favours extreme phenotypes rather than intermediate ones

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8
Q

Evolution

A

A scientific theory that describes changes in a species over time

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9
Q

Fitness

A

The contribution that an individual makes to the next generation by producing offspring that will survive long enough to reproduce

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10
Q

Founder effect

A

A small group of individuals colonizes a new area, and usually do not contain all of the alleles represented in a parent population

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11
Q

Gene flow

A

-describes the movement of alleles from one population to another (migration)
-introduces new alleles to the population, similar to mutation

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12
Q

Gene pool

A

The gene pool of a population includes all of the alleles for all of the genes of each individual in the population

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13
Q

Genetic drift

A

-the change in the frequencies of certain alleles in a small population, caused only by chance.
-alleles appear to “drift” or disappear out of the population, and become lost
-two particular situations lead to genetic drift: the bottleneck effect and the founder effect

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14
Q

Hardy-Weinberg law

A

States that the original genotype proportions will remain constant from generation to generation as long as the following conditions are met: the population must be large, random mating must occur, no mutations must occur, isolation, no natural selection(no genotype can have a reproductive advantage over another)

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15
Q

Hardy Weinberg principle (equations)

A

P^2 + 2pq + q^2 = 1
P + q = 1

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16
Q

Homologous structures

A

-similar structures, different functions
-evidence of a common ancestor

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17
Q

Macroevolution

A

-occurs when members of a population may change so much that they are no longer capable of producing viable, fertile offspring with members of the original population
-when this happens, speciation has occurred

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18
Q

Micro evolution

A

Changing the percentage or frequency of certain alleles within a population leads to evolution within a population

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19
Q

Natural selection

A

The process by which characteristics in a population change over due to the ability of some organisms to survive and reproduce better than others because of the traits they have inherited

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20
Q

Phyletic evolution

A

A pattern of evolution in which the entire population becomes different from the ancestral population, such that there are no members of the original population left

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21
Q

Pre zygotic isolating mechanisms

A

Behavioural, temporal, ecological/habitat, mechanical, gametic isolation

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22
Q

Post zygotic isolating mechanisms

A

Hybrid breakdown, hybrid inviability, hybrid infertility

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23
Q

Stabilizing selection

A

-favours intermediate phenotypes
-selects against extremes, therefore reduces variation
-human birth weight is an example

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24
Q

Vestigial structures

A

Structures that have become reduced in appearance or function over time

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25
Q

Morphological species

A

A group of individuals that have similar physical traits

26
Q

Biological species

A

-A group of individuals that can interbreed in nature and form viable, fertile offspring
-this is the most widely used definition of species

27
Q

Phylogenetic species

A

The smallest group of individuals that share a common ancestor, forming one branch on the tree of life

28
Q

Speciation

A

-the formation of new species from existing species
-it is sometimes referred as macroevolution. It begins with micro evolution.

29
Q

Pre-zygotic (definition)

A

Prevent formation of a zygote

30
Q

Post-zygotic (definition)

A

Prevent zygotes from forming viable, fertile offspring

31
Q

What is a zygote

A

A fertilized egg

32
Q

Behavioural isolation

A

Different species use different courtship and other mating clues to find and attract a mate

33
Q

Temporal isolation

A

Different species breed at different times of the year

34
Q

Ecological/habitat isolation

A

Very similar species may occupy different habitats within a region

35
Q

Mechanical isolation

A

Difference in morphological features may make two species incompatible

36
Q

Gametic isolation

A

Make gametes may be unable to recognize/fertilize an egg of a different species.

37
Q

Hybrid inviability

A

Zygote development is not successful, and the hybrid dies before birth.

38
Q

Hybrid sterility

A

Hybrid is viable but is sterile

39
Q

Hybrid breakdown

A

First generation hybrids are viable and fertile. However, when hybrids mate their offspring are either sterile or weak

40
Q

Divergent speciation

A

-a pattern of evolution in which species that were once similar become increasingly different
-eventually there is no gene flow between populations

41
Q

Sympatric speciation

A

When populations within the same geographical area become unable to reproduce together (common in plants)

42
Q

Convergent speciation

A

A pattern of evolution in which similar traits arise because species have independently or separately adapted to similar conditions

43
Q

Mutation

A

-provide new alleles in a population and therefore allele frequencies change
-mutation alone cannot cause evolution (it must provide a selective advantage)

44
Q

Non-random mating

A

-random mating describes a pattern where any sperm had an equal chance of fertilizing ANY egg in the population
-random mating is rare; individuals usually mate with others in close proximity, or choose mates based on physical/behavioural characteristics(phenotypes) which is not random

45
Q

Fossil evidence

A

-fossils are the remains one impression of a prehistoric organism embedded in rock
-they are evidence of species that existed in the past
-problem: fossils preserve hard structures well, but not soft tissues
^- they only give only a “snapshot” of ancestral forms, but don’t show all changes or details

46
Q

Transitional fossils

A

-Fossils that show links between groups of organisms
-help to show how organisms changed over time

47
Q

Biogeography

A

The study of the distribution of organisms around the world

48
Q

Evidence from biogeography

A

-animals found on islands often closely resemble animals found on the closest mainland
-areas that are close together tend to have related species, even if their environments are very different
-fossils of the same species can be found on the coastline of neighbouring continents

49
Q

Evidence from comparative anatomy

A

Homologous structures, analogous structures, vestigial structures

50
Q

Evidence from comparative embryology

A

Embryos of different organisms show similar stages of development, indicating common ancestry

51
Q

Evidence from molecular biology

A

-the nuclear components that make up all organisms are the same
-in bacteria, plants, animals, and humans, DNA is made of the same 4 nucleotides, and all the proteins are made from combinations of the same 20 amino acids (although several hundred other amino acids do exist)
-this in itself suggests common ancestry

52
Q

Consequences of artificial selection

A

Inbreeding animals can cause some undesirable consequences while selecting for certain desired traits

53
Q

5 points of Darwin’s natural selection

A

-populations have variations
-some variations are favourable to survival
-due to limited resources, more offspring are produced than can survive
-those that survive have favourable traits, and will pass those favourable traits on
-a population will change over time

54
Q

Harmful mutations

A

-produce a change in the individual’s phenotype that reduces the reproductive success of the individual
-the mutation that causes breast cancer

55
Q

Neutral mutations

A

-that provide no benefit or harm to the individual
-the mutations resulting in different colours of eyes

56
Q

Beneficial mutations

A

-produce a change in the individual’s phenotype that gives the individual an advantage in survival and/or reproduction
-the mutation that allows humans to digest cows milk (lactose tolerance)
-the mutation which causes some animals to be born with more fast-twitch muscle fibres than others (making them faster)

57
Q

Selective advantage

A

Something that improves an organism’s chance of passing on their traits

58
Q

Cuvier

A

-using palaeontology he could see past versions of species, seen how they change and disappeared.
-came up with catastrophism - the idea that catastrophes destroyed species living in a particular region, allowing species from neighbouring regions to repopulate the area

59
Q

Lyell

A

-created uniformitarianism - evolution is happening constantly at the same rate over long periods of time

60
Q

Lamarck

A

Characteristics acquired during an organism’s lifetime could be passed on to its’ offspring

61
Q

Darwin

A

Natural selection

Biology (4 decks)

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