USABO - Bio > Unit 4 - Evolution > Flashcards

Unit 4 - Evolution Flashcards

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1
Q

Natural selection

A

prolific reproduction of organisms with favorable traits to aid in survival

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2
Q

Adaptation

A

heritable trait to aid in survival and reproduction dependent on environmental conditions at the time

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3
Q

Divergent Evolution

A

when two species evolve in diverse directions from a common point

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4
Q

Convergent Evolution

A

when similar traits evolve independently in species without a common ancestor

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5
Q

Homologous Structures

A

parts having similar basic forms with various changes and suggest common ancestry

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6
Q

Vestigial Structures

A

structures with no apparent function but is residual of evolutionary change

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7
Q

Species

A

group of individual organisms that breed within own species and produce fertile and viable offspring

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8
Q

Hybrid

A

cross between two species that is likely infertile and unlikely to produce viable offspring

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9
Q

Speciation

A

formation of two species from one original species

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10
Q

Allopatric Speciation

A

geographic separation of species population and their subsequent evolution as a result

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11
Q

Sympatric Speciation

A

when speciation occurs with parent species in similar geographic location

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12
Q

Adaptive Radiation

A

adaptations evolving from a single origin point

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13
Q

Aneuploidy

A

chromosomal error during cell division resulting in divided cells with too many/few chromosomes than species regularly has

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14
Q

Dispersal

A

when a few members of a species move to a new area

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15
Q

Vicariance

A

when a natural situation arises to physically divide organisms

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16
Q

Autopolyploidy

A

when there are 2+ complete chromosome sets from one’s own species

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17
Q

Allopolyploid

A

two different species forming a viable offspring that takes two generation to produce viable and fertile offspring itself

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18
Q

Reproductive Isolation

A

evolutionary process that prevents gene flow between different species

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19
Q

Postzygotic Barrier

A

mechanism blocking reproduction during fertilization

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20
Q

Temporal Isolation

A

difference between inbreeding schedules of different species

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21
Q

Habitat Isolation

A

when species have habitats that no longer overlap

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22
Q

Behavioral Isolation

A

when presence/absence of specific behavior prevents reproduction

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23
Q

Gametic Barrier

A

when differences in gamete structure or sex organ structure do not allow fertilization

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24
Q

Hybrid Zone

A

area where two closely related species continue to interact and reproduce to form hybrids

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25
Reinforcement
when hybrids are less fit and thus less reproduction and species moving further from each other
26
Gradual Speciation Model
species gradually diverge over time
27
Punctuated Equilibrium Model
new species changes due to parent species and remains relatively stable over time
28
Modern Synthesis
established by 1940s as connection between natural selection that is accepted today and impact on genetic makeup
29
Microevolution
change in a single population's trait(s) overtime
30
Macroevolution
change in population that produces new species and taxonomic groups with varying traits
31
Population Genetics
studying how selective forces change within a population through genotypic and allele-based frequencies
32
Allele Frequency
rate at which a specific allele appears in a population
33
Gene Pool
sum of all alleles in a population
34
Founder Effect
event that causes an allele frequency change in isolated part of population that is atypical of original location
35
Genetic Structure
36
Genetic Drift
when frequencies change randomly with no advantage over existing allele rates
37
Hardy-Weinberg's Principle of Equilibrium
describes genetic makeup of a population that states population allele and genotype frequencies are inherently stable (p+q = 1)
38
Population Variation
distribution of phenotypes between individuals influenced by man factors
39
Heritability
fraction of phenotypic variation attributed to genetic variance in a population's genes
40
Genetic Variance
diversity of alleles and genotypes within a population
41
Inbreeding
mating of closely related individuals to raise risk of inheritance of recessive mutations and low immunity
42
Inbreeding Depression
increased likelihood of interbreeding carriers producing diseased offspring
43
Selection Pressure
driving selective force to increase specific trait likelihood in populations
44
Genetic Drift
when allele and genotype frequencies change due to chance; more likely when individual alleles hold more weight in gene pool
45
Bottleneck Effect
when event kills large portion of population; genetic structure of survivors = genetic of entire population now
46
Gene Flow
flow of alleles in/out of population due to migration of individuals/gametes
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Assortative Mating
individual preference to mate with partners that are phenotypically similar
48
Nonrandom Mating
individuals mating with peers nonrandomly and prioritization of a shared trait
49
Geographical Variation
phenotypical variation between populations in different environments
50
Cline
populations of a species vary gradually across environment gradients
51
Evolutionary (Darwinian) Fitness
selection of specific individuals for greater gene pool contributions
52
Adaptive Evolution
selection of beneficial alleles and thus increase in their frequency, while selecting against unwanted alleles and decreasing their frequency
53
Relative Fitness
fitness relative to other members of some species population to determine individual contribution
54
Stabilizing Selection
when natural selection favors average phenotype rather than extreme variation
55
Directional Selection
when the environment changes and phenotypes on one end of the spectrum are selected
56
Diversifying Selection
2+ distinct phenotypes being chosen in having distinct advantages while more average phenotypes are not
57
Frequency-Dependent Selection
when phenotypes of positive frequency (common-low genetic variance) or negative frequency (rare-high genetic variance) are favored
58
Sexual Dimorphisms
sex-based disparity in mating rates
59
Handicap Principle
while practicality of a appendage specific to males may be little, it identifies as being more fit to survive associated risk
60
Good Genes Hypothesis
developed ornamentation to display efficiency of metabolism and immunity
61
Phylogeny
evolutionary history and relationship of organisms or groups of organisms
62
Phylogenetic Trees
illustrations of evolutionary pathways and connections between organisms
63
Taxonomic Classification System
hierarchical organization of species from most broad to most specific; domain, kingdom, phylum, class, order, family, genus, species
64
Rooted
single ancestral lineage from which all organisms relate
65
Branch Point
where a single lineage evolves into a new one
66
Basal Taxon
lineage that evolves early from the root and remains unbranched
67
Sister Taxa
when two lineages stem from same branch point
68
Polytomy
branch with more than two lineages and illustrates where relationships aren't definitively determined
69
Systematics
information is used to organize and classify organisms based on evolutionary relationships
70
Taxonomy
science of classifying organisms to construct universally shared system as placed into specific groups
71
Kingdom
classification of fundamental traits
72
Phylum
classification of fundamental structural features and evolutionary traits
73
Class
more specific shared characteristics
74
Order
division based on more specific categories
75
Family
groups generally related
76
Genus
groups specifically related
77
Species
most specific grouping that can mate with each other and produce viable, fertile offspring
78
Binomial Nomenclature
two word italicized scientific name using both genus + species
79
Taxon
names at each taxonomic level
80
Cladograms
shared derived traits distinguish one group from another
81
Parsimony
simplest and most straightforward way of constructing phylogenetic and evolutionary relationships between organisms
82
Homology
organisms that share similar physical features with close genomes
83
Analogy
organisms share common adaptations evolving within similar environmental conditions, not genetic similarity
84
Molecular Systematics
use of information on a molecular level including DNA analysis
85
Cladistics
organization of homologous traits that sorts them into groups of a single organism (clades)
86
Monophyletic Group/Clade
organisms that share a single common ancestor to include all descendants from a branch point
87
Shared Ancestral Character
shared characteristics found in the ancestor of a group
88
Shared Derived Character
trait derived at a point but does not include all ancestors of the tree
89
Horizontal Gene Transfer (HGT)
transfer of genes horizontally between unrelated species that spurs genetic variation
90
Gene Transfer Agents
small, virus-like particles that transfer random genomic segments from one prokaryote to another
91
Genome Fusion
when 2 symbiotic organisms become endosymbiotic as one species its taken into the cytoplasm of another
92
Nucleus-First Hypothesis
proposes nucleus evolved in prokaryotes first and is followed by a later fusion of the new eukaryote with bacteria to become mitochondria
93
Mitochondria-First Hypothesis
proposes that mitochondria were first established in a prokaryote then required a nucleus by fusion
94
Eukaryotic-First Hypothesis
prokaryotes evolved from eukaryotes by losing genes and complexity
95
Web of Life
eukaryotes evolved from a pool of many species sharing genes by HGT
96
Ring of Life
phylogenetic model where all 3 domains evolve from a primitive pool of prokaryotes
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