Evolution Flashcards
(174 cards)
1
Q
phenotype
A
any observable characteristic of an organism
2
Q
struggle for existence
A
competition or battle for resources needed to live (only the fittest will survive)
3
Q
heredity/inheritance
A
the sum of all biological processes by which particular characteristics are transmitted from parents to their offspring
4
Q
natural selection
A
different alleles of a gene results in different levels of survival and reproduction
5
Q
evolution
A
descent with modification… can be defined more narrowly as the change in the genetic composition of a population over time
6
Q
variation
A
any difference between cells, individual organisms, or groups of organisms of any species cause by genetic differences or environmental factors… arises through development
7
Q
development
A
changes in size, shape, and function during the life of an organism by its genetic potentials are translated into functioning mature systems (genotypes to phenotypes)
8
Q
ecology
A
study of organisms and how they interact with the environment around them
9
Q
adaptation
A
adjustment of organisms to their environment in order to improve their chances at survival in that environment
10
Q
fitness
A
reproductive success and how well an organism is adapted to its environment
11
Q
trade-off
A
one trait cannot increase without a decrease in another
12
Q
genetic disease
A
disease caused in whole or part by a change in the DNA sequence away from the normal sequence
13
Q
sickle cell anemia
A
Low oxygen in the cell clump, jamming the capillaries, which can cause death (genetic disease)
14
Q
chromosome
A
structure found inside the nucleus of a cell… made up of proteins and DNA organized into genes… each cell usually has 23 pairs
15
Q
allele
A
one of 2 or more versions of DNA sequence (a single base or a segment of bases) at a given genomic location
16
Q
balancing selection
A
when multiple alleles are maintained in a population, which can result in their preservation over long evolutionary time periods (ie. malaria and sickle cell allele)
17
Q
evolutionary hitchhiking
A
a phenomenon in which a gene increases in a population because it lies near genes on the same chromosome that are advantageous to an organism
18
Q
stabilizing selection
A
natural selection without evolution… selective force that pushes a population towards the average trait
19
Q
directional selection
A
natural selection where a single phenotype is favored, causing the allele frequency to continuously shift in one direction
20
Q
disruptive selection
A
natural selection where extreme values for a trait are favored over intermediate values
21
Q
sexual selection
A
natural selection where certain characteristics attract the opposite sex and give them higher chances in mating
22
Q
drift/phenotypic drift/genetic drift
A
change in allele frequencies due to chance
23
Q
bottlenecks
A
population is greatly reduced in size… there is no fitness and no selection
24
Q
founder effect
A
the reduction in genomic variability when small group of individuals becomes separated from a larger population
25
adaptive change
evolutionary changes in an organism that makes it suitable to its habitat... driven by selection
26
non-adaptive change
evolutionary changes in an organism that makes it suitable to its habitat... driven by chance
27
mutation
change in DNA sequence of an organism
28
mutation rate
frequency with which a gene changes from the wild-type to a specific mutant
29
immigrations
new organisms joining or entering a different population
30
gene flow
transfer of genetic material from one population to another
31
hardy-weinberg
describes how allele frequencies produce genotype frequencies in one generation if the only thing going on is random mating
32
allele frequency
how common an allele is in a population
33
genotype frequency
proportion of the total number of people represented by a single genotype
34
parthenogenesis
asexual reproduction without males
35
bacteria
microscopic, unicellular, independently reproducing organism
36
archaea
single celled microorganisms with similar structures to bacteria
37
eukaryotes
any single-celled or multicellular organism whose cell contains a distinct, membrane-bound nucleus
38
biological species concept
a species consists of populations of organisms that can reproduce with one another and that are reproductively isolated from other populations
39
ring species
2 populations do not interbreed while living in the same region and connected by a geographic ring of populations (can go one way around, but not the other)
40
cryptic species
one of 2 or more morphologically indistinguishable populations that can't interbreed
41
morphological species concept
species are groups of individuals that are morphologically similar to one another and are morphologically distinct from other such groups
42
chronospecies
2 species that are part of a continuum of change... discontinuity determined by time
43
type specimen
those that are dangerous to dissect due to chances of extinction
44
synonymy
documentation of species name changes
45
speciation
the emergence of new species (new lineages)
46
phyletic change
process of gradual change in a single population
47
anagenesis
change within a lineage
48
cladogenesis
splitting of a lineage into more than one lineage... achieved through speciation
49
allopatric speciation
the formation of new species that occurs due to dispersal or vicariance
50
parapatric speciation
new species evolve in contiguous, yet spatially segregated habitats
51
sympatric speciation
new species evolves from a single ancestral species while inhabiting the same geographic region
52
dispersal
when a population disperses to a new place
53
vicariance
when a population is split by a change in the environment
54
polyploidy
errors during cell division led to an extra set of chromosomes... can lead to new species
55
autopolyploid
occurs when an individual arises from 2 diploid gametes from a single species
56
zygote
fertilized egg cell that results from the union of a female gamete with a male gamete
57
prezygotic barrier (to reproduction)
mechanism that blocks reproduction from taking place by preventing fertilization
58
postzygotic barrier (to reproduction)
a mechanism that blocks reproduction after fertilization and zygote formation
59
habitat isolation
reproductive isolation between 2 populations due to differences in habitats (ie. hawthorne, apple fly)
60
temporal isolation
2 or more species reproduce at different times (ie. reproducing spring vs fall)
61
behavioral isolation
the presence or absence of a specific behavior that prevents reproduction between 2 species from taking place (ie. mating songs)
62
mechanical isolation
can't successfully mate due to differences in reproductive morphologies... does not match (ie. flying squirrels)
63
gametic isolation
binding to some sperm and not others... the compatibility of sperm and egg (ie. sea urchin)
64
sterility
failing to produce or incapable of producing offspring
65
hybrid zone
locations where hybrids between species, subspecies, or races are found... two taxas meet
66
reinforcement
the strengthening of mating isolation in response to selection against unfit hybrids
67
taxon
a taxonomic group of any rank, such as species, family, or class
68
cladogram
diagram that depicts the relative degree of relatedness among taxa, nothing more
69
sister group
branches that share a node
70
node
branch points... represents most recent common ancestors
71
apomorphy
the derived character state
72
synapomorphy
taxa grouped based on shared evolutionary innovations... basis of cladograms
73
plesiomorphy
the primitive character state
74
symplesiomorphy
an ancestral character shared between 2 or more taxa
75
autapomorphy
a derived character in just one taxon (a unique feature)
76
homoplasy
shared character between 2 or more species that did not arise form a common ancestor
77
outgroup
taxa or lineage that is outside a group of taxa being studied
78
character matrix
a table that lists terminal taxa as rows and characters as columns
79
principle of parsimony
idea that, given a set of possible explanations, the simplest explanation is the most likely to be correct
80
cetacean
any members of an entirely aquatic group of mammals of whales, dolphins, and porpoises
81
long branch attraction
rapidly evolving lineages are inferred to be closely related
82
statistical inconsistency
increasing data increasing the support for the wrong answer
83
maximum likelihood
method for the inference of phylogeny... gives the greatest probability of observing the DNA sequences in our data
84
phylogram
the branch lengths are proportional the the strength of support (number of changes on the branch)
85
phlogeny
the branch lengths are proportional to time
86
taxonomies
the science of naming, describing, and classifying organisms
87
monophyletic group
contains all ancestral species and all of its descendants (aka clades)
88
paraphyletic group
contains an ancestral species and some but not all of its descendants
89
polyphyletic group
contains distantly related species but not their most recent common ancestors
90
homology
similarity due to common ancestry... hierarchical in nature
91
convergence/parallelism
evolutionary process where the organism evolve bodily parts that are analogous in terms of structure and function despite their ancestors that are very dissimilar or unrelated
92
phylogenetic species concept
a species is the smallest monophyletic group (lineage) distinguishable by a unique set of either genetic or morphological traits
93
molecular clock
differences in the DNA between species accumulate at a universally constant rate, so the DNA differences between living species could be used to date their times of divergence
94
neutral evolution
most evolutionary changes within species are not caused by natural selection, but genetic drift
95
mutation rate
rate of unpaired DNA changes per nucleotide position per year per individual
96
substitution rate
rate that mutations become fixed in the population... it becomes a characteristic of that population
97
synonymous mutation
change in the DNA sequence that codes for amino acids in a protein sequence, but does not change the encoded amino acid
98
nonsynonymous mutation
nucleotide mutation that alters the amino acid sequence of a protein
99
rate smoothing/relaxed clock analysis
measures the number of changes/mutations that accumulate in the gene sequence of different species over time
100
time tree/chronogram
gives the relative divergence times between the lineages based on the molecular data
101
mitochondria
membrane-bound cell organelles that generate most of the chemical energy needed to power the cell... they have no associated histones and is needed to transcribe and translate DNA into proteins
102
chloroplast
plant cell organelles that convert light energy into stable chemical energy through photosynthesis... they have no associated histones and is needed to transcribe and translate DNA into proteins
103
small subunit ribosomal RNA (SSU rRNA)
a universal phylogenetic tool that is part of the machinery that makes proteins. it is very conserved, so we can recognize it in all species
104
macroevolution
evolution at or above the species level.
105
microevolution
evolution within populations or species, typically just over a few generations
106
preadaptation
a large change in function accomplished with little or no change in structure
107
vertebrate
having vertebrae or a backbone
108
tetrapod
4 legged vertebrates
109
lobe-finned fish
any of various fishes that have paired fins that are rounded and fleshy, suggesting limbs
110
acanthostega
a tetrapod that has a fell set of gills, tail fin, and lateral lines
111
lateral line
sensory organs used by fish
112
archaeopteryx
the first bird
113
character analysis
the process of identifying homologs based on morphology alone
114
compound eye
a visual organ found in arthropods such as insects and crustaceans... it consists of a cornea, lens, and photoreceptor cells that distinguish brightness and color
115
last universal common ancestor (LUCA)
the most recent population of organisms from which all organisms now living on Earth share common descent
116
hydrothermal vent
results of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centers or subduction zones
117
planktotrophic larvae
the larvae of some species live in the plankton, feeding on planktonic organisms
118
non-planktotrophic larvae
larvae that settle to the bottom directly without feeding in the plankton
119
punctuated equilibrium
majority of morphological change occurred rapidly during speciation, following by long periods of stasis
120
phyletic gradualism
phenotypic changes accumulate gradually within species
121
varves
annual sedimentary layers from glacial lakes
122
species sorting
species distributions and abundances can be related to the environment or biotic conditions in a particular habitat
123
directed speciation
when on average the direction of speciation is biased
124
asymmetric increase in variance
when the clade begins close to a boundary, so overtime it will move on average to larger body sizes, even if there is no bias in the size of each new species
125
end-permian mass extinction
largest distinction event that was triggered by volcanism. it resulted in massive climate change, which reshaped the biosphere
126
end-cretaceous mass extinction
triggered by meteorite impact and/or volcanism, it led to a short-term climate change, disrupting the base of the food chain and reshaping the biosphere
127
iridium (anomaly)
unusual abundance of the chemical element iridium in a layer of rock strata
128
chicxulub crater
impact crater buried underneath the yucatan peninsula in mexico
129
mantle plume
area under the rocky outer layer of earth, called the crust, where magma is hotter than surrounding magma
130
large igneous province (LIP)
voluminous emplacements of predominantly mafic extrusive and intrusive rock whose origins lie in processes other than normal seafloor spreading
131
siberian traps
remnants of widespread volcanic activity that occurred in northern pangea
132
multicellularity
an organism composed of many cells, which are to varying degrees integrated and independent
133
cyanobacteria
aquatic and photosynthetic bacteria
134
brown algae
group of algae belonging to class phaeophyceae (ie kelp)
135
red algae
oldest type of eukaryotic algae that are mostly found in freshwater lakes
136
golden algae
microscopic, single celled species of algae
137
slime molds
informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free living single celled stage and the formation of spores
138
theia
a smaller proto-planet
139
pallasite meteorites
meteorites with mantle remnants embedded in a matrix of iron-nickel matrix derived from the core
140
sedimentary rock
type of rock that are formed by the accumulation or deposition of mineral or organic particles at earth's surface
141
faint early sun
luminosity increase by 50% over the last 4 Ga
142
stromatolites
layered structures made by the binging and cementation of sedimentary grains by biofilms and microorganisms
143
great oxygenation event
oxygen begins to acculumate in the atmosphere/oceans 2.45 Ga ago... oxygen produced by bacterial photosynthesis
144
snowball earths
hypothesis that in the distant past, the earth's surface was entirely frozen from pole to pole
145
slushball earth
hypothesis that earth was not completely frozen over during period of extreme glaciation in precambrian times
146
cambrian 'explosion'
the relative rapid and unique appearance in the of fossil record of virtually all the animal body plans
147
phyla/body plans
a suite of characters shared by a group of phylogenetically related animals at some point during their development
148
sponges
the first animals... they have no tissues nor organs (no cell layer)
149
diploblasts
having two primary cell layers... the endoderm and the ectoderm
150
triploblasts/bilaterians
having three primary cell layers... endoderm, ectoderm, and mesoderm
151
endoderm
the gut
152
ectoderm
the outside
153
mesoderm
the heart, muscle, bones, etc
154
ediacarans
represents the earliest known assemblage of complex multicellular organisms... they are simple filter feeders who feed on bacterial mats on the sea floor
155
trace fossils
geological records of the activities and behaviors of past life
156
small shelly fossils
mineralized fossils who provide relatively continuous record throughout the early cambrian... gives insight into the cambrian explosion
157
chengjiang biota
most diverse assemblage of early cambrian marine fossils known... not only has hard skeletal parts, but it also preserves in exquisite detail nonmineralized skeletal parts and internal soft parts of organisms
158
burgess shale biota
fossil-bearing deposit exposed in the canadian rockies... it is famous for the exceptional preservation of the soft parts of its fossils
159
bilaterian developmental system
the change from simple to complex organisms
160
hox genes
order of the genes is the order that it is expressed in the body plan
161
eyeless/pax6
can initiate eye development in the fly
162
sahelanthropus
extinct species of the homininae (african apes) dated around 7 million years ago during the miocene epoch
163
ardipithecus
earliest known genus of the zoological family hominidae
164
australopithecus afarensis (lucy)
extinct species of australopithecine which lived in the pilocene of east africa...
165
homo erectus (narikotome boy)
extinct species of the human genus, perhaps an ancestor of modern humans
166
homo sapiens
the species to which all modern human beings belong
167
oldowan tools
stones that were smashed and broken to give a jagged edge on one end... first stone tools made by homo habilis
168
acheulean tools
replaced oldowan tools are bifacial and could produce 12 inches of cutting edge... it is much more complicated
169
coalesence time
the time of the last common ancestor for the variants of a gene
170
hunter-gatherers
a type of subsistence lifestyle that relies on hunting and fishing animals and foraging for wild vegetation and other nutrients like honey, for food
171
childhood
post breast-feeding dependency on others for food
172
menopause
older females lose the ability to have offspring
173
group selection
social cohesion, and later language and culture, played a major role in determining which groups were able to pass their genes on to the next generation
174
non-infectious mismatch diseases
mismatch between our current lifestyle and our deep evolutionary history
