exam 1 review guide Flashcards
1
Q
Linnaeus
A
- species are fixed and eternal but varieties can arise due to environmental conditions
- created binomial nomenclature
- sought order in God’s creation
- classified organisms based on similarities
2
Q
Lyell
A
- uniformitarianism: geological processes occur at the same rate that they did in the past
- earth must be older than previously thought
3
Q
George Cuvier
A
- father of paleontology
- catastrophism: idea that if species were knocked out due to disaster, migrant populations would move in from nearby
4
Q
lamarck
A
- use and disuse and inheritance of acquired characteristics
- recognized similarities in fossils and believed organisms could change over time
5
Q
Malthus
A
- struggle for existence was due to population growth
- due to overpopulation, lack of resources, and irresponsible lower class
6
Q
Wallace
A
- traveled to amazon; shipwrecked
- looked at adaptations of butterflies to environment in Malaysia
7
Q
Darwin
A
- went on HMS beagle to study organisms; found how organisms adapted to differing environments
- organisms in south america were different than in europe
8
Q
effects of overpopulation
A
- more individuals than resources can support
- population size increases as all organisms reproduce
- overpopulation leads to struggle of existence (only some survive)
9
Q
natural selection
A
- differential success in reproduction
- acts upon existing varitation
- certain traits give some organisms a higher chance of reproduction and survival
10
Q
artificial selection
A
-combining two organisms with favorable traits to quickly increase the organisms in a population with favorable characteristics
11
Q
how does selection act on populations
A
- individuals cannot evolve
- natural selection is not driven by anything
- selection acts on phenotype but evolution changes allele frequencies
12
Q
common ancestory
A
related through common ancestor
13
Q
types of homology
A
-morphological, embryological, molecular
14
Q
morphological homology
A
physical appearance of organisms
15
Q
embryological homology
A
only can be observed at specific developmental stage
16
Q
molecular homology
A
similarities in gene or protein sequence
17
Q
vestigial structures
A
-structures that provide additional evidence of common ancestory; were important characters for ancestors but no longer serve function
18
Q
evidence for natural selection
A
-homology, fossil record, biogeography
19
Q
homology
A
-similarities in organisms resulting from common ancestry
20
Q
requirement for organisms to be homologous
A
-must be a modification of the same character in a common ancestor
21
Q
biogeography
A
-geographic distribution of species (closer=more likely related)
22
Q
fossil record
A
-used to estimate ages of particular organisms found there
23
Q
source of variation in populations
A
-mutations
24
Q
population genetics
A
study of genetic variation within populations
25
population
-group of interbreeding individuals of the same species that share a common set of genes
26
gene pool
collection of genes shared by individuals in a population
27
genotype frequency
proportion of individuals in population with particular genotype
28
allele frequency
proportion of particular allele in a population
29
what does it mean when a population is in hardy weinberg
not evolving
30
five conditions of hardy weinberg
-large population size (genetic drift), no migration (gene flow), no mutation, random mating, no selection
31
heterozygote advantage
when individuals that are heterozygotes at a particular locus have greater fitness than both kinds of heterozygotes
32
3 mechanisms that cause allele frequency change
-natural selection, genetic drift, gene flow
33
frequency dependent selection
- fitness of a phenotype depends on how common it is in a population
- selection favors the phenotype that is least common
34
directional selection
-conditions favor individuals exhibiting on extreme of a phenotypic range
35
diversifying selection
-occurs when conditions favor individuals at both extremes of a phenotypic range over intermediates
36
stabilizing selection
-acts against both extreme phenotypes and favors intermediate variants
37
sexual selection
-individuals with certain inherited characteristics are more likely than others of the same species to get a mate
38
why natural selection cannot create perfect organisms
- acts on what is already present
- evolution is random and adaptive
- selection works on existing variants
39
genetic drift
- chance events that alter allele frequencies
| - unpredictable changes
40
bottleneck effect
- severe drop in population size
| - can decrease genetic variation
41
gene flow
- transfer of alleles between populations due to the movement of fertile individuals or their gametes
- tends to reduce genetic differences
42
founder effect
- when individuals become isolated from the larger population, the smaller group may establish a new population whose gene pool differs from the source population
- example: storm blows some members of a population to a new island
43
polymorphism
44
clinal variation
45
the red queen effect
-the evolutionary arms race between predator and prey or parasite and host
46
microevolution
-change in allele frequencies from generation to generation
47
what is a species (BSC)
-group of actually or potentially interbreeding organisms capable of producing fertile offspring
48
prezygotic barriers
- temporal (mate in different seasons)
- habitat (live in different habitats)
- behavioral(mating behaviors are important to mate with another organism)
49
barriers that prevent hybridization if individuals of different species try to mate
- mechanical : insect genitalia works like a lock and key to provide post mating block to fertilization
- gametic isolation: post mating block to fertilization
50
post fertilization blocks (postzygotic)
- reduced hybrid viability
- reduced hybrid fertility
- hybrid breakdown
51
problems with BSC
- knowledge of mating habits is required
- only applies to organisms that reproduce sexually
- fossils
52
morphological species concept
- defines species based on physical appearance
- not useful for species that all look alike (bacteria/protists)
- there can be morphological variation in the same species
53
behavior species concept
54
pluralistic species concept
-different criteria can be applied to different organisms
genealogical or phylogenetic: species are irreducible clusters of organisms that are diagnosable distinct from other such clusters and within which is parental pattern of ancestry and descent
-fixed characters are evidence of reproductive isolation
-fixed characters cannot be found anywhere else
-drawback is sample size
55
allopatric speciation
-requires geographic isolation
56
sympatric speciation
-occurs without geographic speciation
57
types of sympatric speciation
- polyploidy (extra sets of chromosomes due to accidents during cell division)
- sexual selection (mate preference can lead to speciation)
- habitat differentiation (appearance of new ecological niches)
58
how do errors in meiosis lead to sympatric speciation in plants (allopolyploid and autopolyploid)
- nondisjunction (failure of chromosome separation)
- autopolyploid: individual with more than two chromosome sets from a single species
- allopolyploid: species with multiple sets of chromosomes from different species
59
alternatives to hybrid zones
-reinforcement, fusion, stability
60
relative fitness
- contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals
- indirectly acts of genotype
61
intrasexual selection
-selection within same sax where individuals of one sex compete for mates of other sex
62
intersexual selection
-individuals of one sex select their mates from other sex (mate choice)
