Exam 1 Review Flashcards
1
Q
what is evolution?
A
a change in the prevalence of traits within a population of organisms from one generation to another
2
Q
what researchers influenced Darwin?
A
Buffon, Cuvier, Lamarck, Lyell, Malthus
3
Q
what did buffon believe/discover?
A
related species came from common ancestors
4
Q
what did cuvier believe/discover?
A
theory of catastrophism
5
Q
what did lamarck believe/discover?
A
hypothesized that species change over time
6
Q
what did lyell believe/discover?
A
earth is older than 60,000 years
7
Q
who were Darwin’s mentors?
A
Lamarck, Lyell, Malthus
8
Q
how did malthus influence him?
A
resources are limited, so species competed
9
Q
what discoveries did Darwin make on his trip on the Beagle?
A
different types of finches, show similarity with mainland birds, brought up the idea of common ancestors
10
Q
who was Alfred Russell Wallace?
A
another naturalist, was studying evolution too and reached out to Darwin
11
Q
why did Darwin wait so long to publish?
A
he was scared of peoples reactions especially the church
12
Q
how did Darwin believe evolution occurred?
A
evolution happens through natural selection
13
Q
three criteria for evolution to be present according to Darwin
A
-variation of alleles for a trait
-trait has to be heritable
-has to be differential reproductive success as a result of that trait
14
Q
what is the outcome of natural selection on populations?
A
fitness increasing alleles become more common
15
Q
how does natural selection lead to adaptation?
A
weak traits will slowly die off and wont be passed anymore
16
Q
what is a population?
A
group of one species
17
Q
what is a gene pool?
A
the total genetic diversity found in a population
18
Q
at what level does evolution act?
A
level of population
19
Q
at what level does natural selection act?
A
level of the individual organism
20
Q
what is the difference between natural selection and evolution?
A
evolution is gradual change, natural selection is a mechanism of a population best suited for their environment will survive. natural selection contributes to evolution
21
Q
what is a SNP, how does it contribute to variation?
A
its a nucleotide, change in SNP can cause a trait to be favored by natural selection
22
Q
what is polymorphism?
A
2 different forms of something
23
Q
how does polymorphism contribute to variation of a trait in a population?
A
results of it cause several different forms of a single species, dividing the population in distinct forms
24
Q
conditions needed for a population to be in Hardy-Weinberg equilibrium
A
-large population
-random mating
-no migration
-no mutation
- no selection
25
what does it mean for a population to be in H-W equilibrium?
its not evolving
26
what is microevolution?
changes in allele frequency within a population
27
requirements for microevolution to occur
-mutation
-natural selection
-genetic drift (random)
-migration
-nonrandom mating
-small population
28
evidence of microevolution occurring today
pesticide resistance, antibiotic resistance
29
what is natural selection?
differential survival and reproduction of individuals due to difference in phenotype
30
what is the result of natural selection?
favorable traits are transmitted through generations
31
the different mechanisms involve in natural selection
directional, stabilizing, disruptive
32
what is the directional mechanism
selection for extreme phenotype
33
what is the stabilizing mechanism?
selection for intermediate phenotype, against any extremes
34
what is the disruptive mechanism?
selection for 2 or more phenotypes
35
what is sexual selection?
individuals with certain inherited traits are more likely than others to obtain mates, leads to secondary sexual characteristics
36
what are secondary sexual characteristics?
formed during puberty, physical traits that aren't reproductive
37
what is sexual dimorphism?
difference in form between individuals of different sex in same species
38
what are intrasexual characteristics?
traits that members of the same sex compete with for access to the opposite sex
39
what are intersexual characteristics?
one sex chooses mates from multitudes of opposite sex individuals
40
why are females the most choosiest sex?
males traits show information about health and ability to reproduce so they pick the best
41
why do males compete?
males compete because they want to increase their reproductive output as much as possible
42
what is runaway selection?
female choice leads to the development of male secondary characteristics, leads to more exaggerated traits, females like big so it keeps getting bigger over generations
43
what is a honest signal?
a trait that cannot be faked
44
what does balancing selection do?
help maintain variation at some chromosomal loci, brings allele to intermediate equilibrium
45
what are the two types of balancing selection?
frequency dependent and heterozygote advantage
46
what is frequency dependent selection?
situation where fitness is depended upon the frequency of the phenotype or genotype in a population
47
what is heterozygote advantage selection?
balancing selection favors heterozygotes over homo due to environmental conditions
48
what is genetic drift?
change in allele frequency in a population due to random chance, can lead to fixation of an allele and reduce variation
49
what are the different types of genetic drift?
founder effect, bottleneck effect
50
what is the founder effect?
subset of the original population separates and creates a newer population with fewer alleles
51
what is the bottleneck effect?
when a population is subjected to a disaster
52
does genetic drift occur all the time?
yes, it happens to all populations
53
what types of populations does genetic drift have the largest impact on?
small populations
54
what does it mean if a allele becomes fixed in a population?
allele is present at a frequency of 1.0 so all individuals in the population have the same allele
55
what does fixation mean in terms of variation for a trait?
change in gene pool from two variants of a particular gene existing to just one of the gene variations remaining
56
what is the role of migration?
causes gene flow and changes the alleles in a population
57
what is bidirectional migration and its effect?
when individuals from two different populations are free to move back and forth, reduces differences in allele frequency between populations, increases genetic variation within a population
58
what is assortive mating?
individuals of similar phenotypes are more likely to mate, increases homozygotes and diverges populations
59
what are the results of non random mating?
higher chance of recessive diseases, lower fitness
60
what is interbreeding depression?
the reduces survival and fertility of offspring of inbreeding
61
what is the geologic time scale?
chronicles of the major events in earth's history, divided into 4 eons then eras
62
how does fossil evidence show transitions between major groups
fossils found provide a link between life in sea and tetrapod's on land
63
how can fossils be formed?
in sedimentary rock, can be formed from compression, petrification, impression, cast and intact preservation
64
what are the biases that are used in the fossil record?
anatomy, size, number, environment, time, geology and paleontology
65
what are the 2 types of dating?
radiometric and relative dating
66
what are the different radiometric dating isotopes?
carbon-14, potassium- 40, uranium-238
67
what is the age range for carbon-14?
less than 50,000 years old
68
what is biogeography?
study of the geographic patterns of species around the world
69
what are endemic animals?
native animals, only found in one location
70
what are marsupials?
non placental mammals that carry offspring in pouches
71
what are monotremes?
non placental mammals that lay eggs
72
why aren't then large numbers of marsupials around the world?
they are physically isolated in australia
73
what is wallaces line?
imaginary line that separates the species found in Australia and southest asia
74
why are islands a good source of evolutionary evidence?
they have endemic species that are often closely related to species found on the nearest mainland
75
can evolution be witnessed happening in our lifetime?
yes
76
how does antibiotic resistance occur in bacteria?
bacteria can transfer their resistance to others even if not offspring
77
what is convergent evolution?
distantly related organisms independently evolve similar traits to adapt to similar necessities
78
what are analogous structures?
structures that look similar in structure and function but evolve independently
79
what are homologous structures?
anatomical similarities that represent variations with common ancestors
80
what are vestigial structures?
anatomical structures that have no current function but resemble structures of ancestors
81
what is a example of a vestigial structure?
wisdom teeth, tonsils
82
what is Evo-Devo?
study of the developmental history of species to look at similarities
83
what is heterochrony?
changes in rate and time of developmental events
84
what are hox genes?
they provide information on the position on the body during development, duplication leads to more complex body structures
85
what are Pax6 genes?
genes that code for eye development
86
what is pedomorphosis?
when adult remains with juvenile traits of an ancestor
87
what are molecular clocks?
technique that uses mutation rate of biomolecules to deduce the time that evolution occurred
88
what is macroevolution?
major evolutionary changes
89
what does macroevolution lead to?
the formation of new species or groups of related species
90
difference between micro and macro evolution?
micro is small changes over short periods of time and macro is larger changes over a long period of time
91
what is a species?
group of related individuals that have common attributes, potential to interbreed but offspring has to be fertile
92
what are the different species concepts?
biological, phylogenetic, ecological, morphological
93
what is the biological concept defined of?
species defined by the ability to interbreed
94
what is the phylogenetic concept defined of?
species share common ancestors
95
what is the ecological concept defined of?
unique set of resources and habitat they need
96
what is the morphological concept defined of?
their physical features
97
what is reproductive isolation?
mechanism to used prevent different species from interbreeding
98
what are the two types of reproductive isolation?
prezygotic and postzygotic isolation
99
what is prezygotic isolation?
mechanism that prevents zygote from forming
100
what is postzygotic isolation?
offspring is formed but has issues
101
what are the different mechanisms of prezygotic isolation?
habitat isolation, temporal isolation, behavior isolation, mechanical isolation, gametic isolation
102
what are the different mechanisms of postzygotic isolation
hybrid in viability, hybrid sterility, hybrid breakdown
103
what is speciation?
the formation of a new species or distinct species in a cause of evolution
104
two ways speciation occurs
cladogenesis and anagenesis
105
what is cladogenesis?
splitting one species into two
106
what is anagenesis?
gradual evolution of species that continues to exist
107
what are the two types of speciation?
allopatric speciation, paratactic speciation
108
what is allopatric speciation?
geographic barriers do not allow for gene flow
109
what is paratactic speciation?
population enters a new area that borders parent population
110
what is adaptive radiation?
rapid increase in the number of species with a common ancestor, followed after a mass extinction
111
what is sympatric speciation?
speciation that takes place in the same habitat
112
how does sympatric speciation happen?
polyploidy- changes in chromosome number due to errors in meiosis
113
what is gradualism?
pace of evolution, each species gradually evolves over time
114
what is punctuated equilibrium?
pace of evolution, unchanged for long periods, small changes accumulate then rapid change is seen
115
what are hybrid zones?
incomplete geographic barriers that have interbreeding occuring
116
what are the possible hybrid outcomes?
reinforcement, fusion, stability
117
what is reinforcement?
hybrid zone outcome, reproductive barrier is reinforced
118
what is fusion?
hybrid zone outcome, barrier weakens and fuse together to make one
119
what is stability?
hybrid zone outcome, two species remain different, but the production of hybrids continues
120
how does mass extinction lead to adaptive radiation?
it creates niches, ecological role an organism has in a habitat
121
what are the different stages of life?
stage 1: generation of small organic molecules
stage 2: organic monomers joint to form polymers
stage 3: genetic material in the form of RNA provides ability for self replication
stage 4: polymers enclosed by a boundary
122
what is the hypothesis of how biological molecules first appeared?
spontaneous events produced from atoms in early earth's atmosphere
123
what gasses did early earths's atmosphere have?
water vapor, hydrogen gas, methane, ammonia, no oxygen
124
what was the Miller-Urey experiment?
it recreated earth's early atmosphere, found amino acids where being formed, esp after volcanic eruptions
125
what are the other two less popular hypothesis about the origin of life?
extraterrestrial- organic molecules came from a meteorite
deep sea vent- cracks in the earth's surface creates vents to release heat under sea
126
what was the first organic polymer to form?
RNA
127
why is RNA a special polymer?
it stores genetic information and also catalyzes chemical reactions
128
what are photobionts?
the first formed cell, lipid bi layer allows it to maintain internal environment
129
what are earth's 4 eons?
hadean, archean, proterozoic, phanerozoic
130
when did life first appear on the fossil record?
archean eon, 3.5 billion years ago, it was cyanobacteria
131
what eon did eukaryotes first appear?
proterozoic eon, 2-1.5 billion years ago
132
what is so significant about the cambrian period?
marked the beginning of diversity, 550 million years ago
133
what events allowed the cambrian explosion to happen?
increase of oxygen gas allowed for more complex life forms
134
in what era did the Cambrian explosion occur?
paleozoic era, in phanerozoic eon
135
when did vascular plants make an appearance in the fossil record?
paleozoic era, in phanerozoic eon
136
what were the major mass extinctions events that occurred?
the ordovician- mostly marine 86%
the late devonian- 75%
the great dying- 96%, marked the end of the paleozoic era and beginning of mesozoic
137
what occurs after a mass extinction?
the biodiversity is increased
138
what was the era of dinosaurs?
mesozoic era
139
was the triassic period in the mesozoic era?
yes, phanerozoic eon >mesozoic era >triassic period
140
what event made mammals the dominant animal on earth?
the cretaceous extinction
141
what period did the hominins emerge?
tertiary period
142
when did modern humans evolve?
300,00 years ago
