exam1 vocab, Manson Flashcards
1
Q
convergent evolution
A
the evolution of similar features in independent evolutionary lineages
2
Q
natural selection
A
a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits
3
Q
evolutionary tree
A
a branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms
4
Q
biogeography
A
the scientific study of the past and present geographic distributions of species
5
Q
pangea
A
the supercontinent that formed near the end of the Paleozoic era, when plate movement brought all the landmasses of Earth together
6
Q
analogous
A
having characteristics that’re similar because of convergent evolution (not homologous)
7
Q
adaptation
A
inherited characteristic of an organism that enhances its survival and reproduction in a specific environment
8
Q
homology
A
similarity in characteristics resulting from a shared ancestry
9
Q
paleontology
A
the scientific study of fossils
10
Q
vestigial structure
A
a feature of an organism that is a historical remnant of a structure that served a function in the organism’s ancestors
11
Q
fossils
A
a preserved remnant or impression of an organism that lived in the past
12
Q
evolution (descent with modification, a change in the genetic composition of a population from generation to generation)
A
the process by which species accumulate differences from their ancestors as they adapt to different environments over time
13
Q
homologous structures
A
structures in different species that are similar because of common ancestry
14
Q
artificial selection
A
the selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits
15
Q
stratum
A
a rock layer formed when new layers of sediment cover older ones and compress them
16
Q
vestigial organs
A
remnants of structures that were useful to an organism’s ancestors but are now nonfunctional or show a reduced function
17
Q
balancing selection
A
a type of natural selection that maintains two or more phenotypic forms in a population
18
Q
Hardy-Weinberg equilibrium
A
the state of a population in which frequencies of alleles and genotypes remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work
19
Q
heterozygote advantage
A
greater reproductive success of heterozygous individuals compared with homozygotes; tends to preserve variation in a gene pool
20
Q
sexual selection
A
a process in which individuals with certain inherited characteristics are more likely than other individuals of the same sex to obtain mates
21
Q
sexual dimorphism
A
differences between the secondary sex characteristics of males and females of the same species
22
Q
microevolution
A
evolutionary change below the species level; a change in the alleles frequencies in a population over generations
23
Q
intersexual selection (mate choice)
A
a form of natural selection in which individuals of one sex are choosy in selecting their mates from the other sex
24
Q
frequency-dependent selection
A
selection in which the fitness of a phenotype depends on how common the phenotype is in a population
25
bottleneck effect
genetic drift that occurs when the size of a population is reduced by a natural disaster or human actions. usually the surviving population is no longer genetically representative of the original population
26
genetic drift
a process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. effects are most pronounced in small populations
27
founder effect
genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition isn't reflective of that of the original population
28
population
a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring
29
gene pool
the aggregate of all copies of every type of allele at all loci in every individual in a population
30
disruptive selection
a type of natural selection in which individuals on both extremes of a phenotypic range survive or reproduce more successfully than do individuals with intermediate phenotypes
31
gene flow
the transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes
32
adaptive evolution
when traits that enhance survival or reproduction tend to increase in frequency over time, resulting in a better match between organisms and their environment
33
genetic variation
differences among individuals in the composition of their genes or other DNA sequences
34
intrasexual selection
a form of natural selection in which there's direct competition among individuals of one sex for mates of the. opposite sex
35
stabilizing selection
a type of natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes
36
neutral variation
genetic variation that doesn't provide a selective advantage or disadvantage
37
relative fitness
the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals in the population
38
directional selection
a type of natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals
39
hybrid
offspring that results from the mating of individuals from 2 different species or from 2 true-breeding varieties of the same species
40
allopolyploid
a fertile individuals that has more than 2 chromosome sets as a result of 2 different species interbreeding and combining their chromosomes
41
macroevolution
evolutionary change above the species level (the broad pattern of evolution at a species level)
42
reproductive isolation
the existence of biological factors (barriers) that impede members of 2 species from producing viable, fertile offspring
43
morphological species concept
a definition of a species in terms of measurable anatomical criteria
44
ecological species concept
a definition of a species in terms of ecological niche (the sum of how members of the species interact with the nonliving and living parts of their environment)
45
sympatric speciation
the formation of a new species in populations that live in the same geographic area
46
polyploidy
a chromosomal alteration in which the organism possesses more than 2 complete chromosome sets (a result of accidental cell division)
47
prezygotic barrier
a reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted
48
microevolution
evolutionary change below the species level (the change in the allele frequencies in a population over generations)
49
punctuated equilibria
long periods of apparent stasis where a species undergoes little or no morphological change, interrupted by relatively brief periods of sudden change
50
postzygotic barrier
a reproductive barrier that prevents hybrid zygotes produced by 2 different species from developing into viable, fertile adults
51
reinforcement
a process where natural selection strengthens postzygotic barriers to reproduction, reducing the chances of hybrid formation (more likely to occur if hybrid offspring are less fit than members of the parent species)
52
biological species concept
a definition of a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring but don't produce viable, fertile offspring members of other such groups
53
allopatric speciation
the formation of new species in populations that are geographically isolated from one another
54
speciation
an evolutionary process where one species splits into 2 or more species
55
autopolyploid
an individual that has over 2 chromosome sets that are all derived from a single species
56
hybrid zone
a geographic region where members of different species meet and mate, producing at least some offspring of mixed ancestry
57
species
a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring but don't produce viable, fertile offspring with members of other groups
58
half-life
the amount of time it takes for half of a sample of a radioactive isotope to decay
59
pangea
the supercontinent that formed near the end of the Paleozoic era, when plate movements brought all the landmasses of Earth together
60
adaptive radiation
a period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles in their communities
61
ribozyme
an RNA molecule that functions as an enzyme, like an intron that catalyzes its own removal during RNA splicing
62
paedomorphosis
the retention in an adult organism of the juvenile features of its evolutionary ancestors
63
macroevolution
evolutionary change above the species level (like the origin of a new group of organisms through a series of speciation events)
64
protocell
an abiotic precursor of a living cell that had a membrane-like structure and that maintained an internal chemistry different from that of its surroundings
65
alkaline vent
a deep-sea hydrothermal vent that releases water that's warm and has a high pH (might've been the location of the earliest abiotic synthesis of organism compounds)
66
Cambrian explosion
a relatively short time in geologic history where many present-day phyla of animals appeared in the fossil record (the emergence of the first large hard-bodied animals) (around 525 million years ago)
67
radiometric dating
a method for determining the absolute age of rocks and fossils, based on the half-life radioactive isotopes
68
endosymbiosis
a relationship between 2 species in which one organism lives inside the cell of another organism (ex: mitochondria and chloroplasts)
69
stromatolite
layered rock that results from the activities of prokaryotes that bind thin films of sediment together
70
serial endosymbiosis
a hypothesis for the origin of eukaryotes where a sequence of endosymbiotic events occurred, in which mitochondria, chloroplasts, and other cellular structures were derived from small prokaryotes that were engulfed by larger cells
71
homeotic gene
any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells
72
mass extinction
the elimination of a large number of species throughout Earth, the result of global environmental changes
73
heterochrony
evolutionary change in the timing or rate of an organism's development
74
plate techtonics
the theory that the continents are part of great plates of Earth's crust that float on the hot, underlying portion of the mantle (movements of the mantle cause the continents to move slowly over time)
75
hydrothermal vent
an area on the seafloor where heated water and minerals from the Earth's interior gush into the seawater, producing a dark hot and oxygen-deficient environment (producers in this environment are chemoautotrophic prokaryotes)
76
domain
the broadest taxonomic category (archaea, bacteria, eukarya)
77
kingdom
a taxonomic category above phylum
78
phylum
in Linnaean classification, the taxonomic category above class
79
class
in Linnaean classification, the taxonomic category above the level of order
80
order
in Linnaean classification, the taxonomic category above the level of family
81
family
in Linnaean classification, the taxonomic category above genus
82
genus
a taxonomic category above the species level
83
analogy
similarity between 2 species due to convergent evolution rather than descent from a common ancestor with the same trait
84
orthologous genes
a type of homologous genes that are found in different species due to speciation
85
paralogous genes
a type of homologous genes that are found in the same genome as a result of gene duplication
86
monophyletic
describing a group of taxa that consist of a common ancestor and all of its descendants (equivalent to a clade)
87
paraphyletic
describing a group of taxa that consist of a common ancestor and some but not all of its descendants
88
polyphletic
describing a group of taxa that includes distantly related organisms but doesn't include their most recent common ancestor
89
ingroup
a species or group of species whose evolutionary relationships are being examined in a given analysis
90
outgroup
a species or group of species from an evolutionary lineage that's known to have diverged before the ingroup (selected so that the ingroup is not closely related)
91
clade
a group of species that include an ancestral species and all of its descendants (equivalent to a monophyletic group)
92
branch point
the representation of the divergence of 2 or more taxa from a common ancestor on a phylogenetic tree
93
rooted
describing a phylogenetic tree that contains a branch point, representing the most recent common ancestor of all taxa in the tree
94
taxon
a named taxonomic unit at any given level of classification
95
sister taxa
groups of organisms that share an immediate common ancestor (each other's closest relatives)
96
basal taxon
in a specified group of organisms, a taxon whose evolutionary lineage diverged early in the history of the group
97
binomial
a common term for the 2-part latinized format for naming a species, consisting of the genus and specific epithet (aka binomen)
98
phylogeny
the evolutionary history of a species or group of related species
99
cladistics
an approach to systematics in which organisms are placed into clades based primarily on common descent
100
molecular clock
a method for estimating the time required for a given amount of evolutionary change, based on the observation that some regions of genomes evolve at constant rates
101
horizontal gene transfer
the transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and the fusion of different organisms (endosymbiosis)
102
evolutionary lineage
the sequence of ancestral organisms leading to a particular taxon (represented by a branch in a phylogenetic tree)
103
shared ancestral character
a character shared by members of a particular that originated in an ancestor that's not a member of the clade
104
shared derived character
an evolutionary novelty that's unique to a particular clade
105
systematics
a scientific discipline focused on classifying organisms and determining their evolutionary relationships
106
maximum liklihood
as applied to DNA sequence data, a principle that states that when considering multiple phylogenetic hypotheses, take the one with the highest probability of occurrence
107
maximum parsimony
the principle that when considering multiple explanations for an observation, take the one with the simplest explanation that stays consistent with the facts
