envs lecture 2 Flashcards
1
Q
who talked about evolution pre-darwin
A
plato and aristotle
2
Q
what is one of the big questions in evolutionary biology
A
how to explain variation in nature, within species, etc.
3
Q
what is concept of eidos
A
‘form’ or ‘idea’ or ‘essence’
4
Q
give example of essentialism
A
horses have an immutable (fixed/unchangeable) properties, but each individual has its imperfections
5
Q
what is essentialism/pre-darwinian view
A
variation is accidental imperfection
6
Q
where does this pre-darwinian view come from
A
from a perception of creationism; idea that life was created by an all powerful being, all life was perfect
7
Q
basically what did pre-darwinians think
A
variation is imperfection
8
Q
what happened in 18th century w/r to thinking of evolution
A
profound changes in thinking about nature and history of earth
9
Q
uniformitarianism
A
present is the key to the past
10
Q
who came up w/ uniformitarianism
A
geologists James Hutton, Charles Lyell
11
Q
what is catastrophism
A
sudden violent and short-lived events were responsible for current state of the earth
12
Q
what did Hutton and Lyell argue
A
the same geological processes operated in the past as in present, and therefore geological data could be explained by causes that we observe
13
Q
what contrasts w/ uniformitarianism
A
catastrophism
14
Q
describe catastrophism
A
ties the current state of the earth to sudden violent and short-lived events like volcanism, or events like asteroid impacts
15
Q
describe reality w/r to uniformitarianism
A
both ongoing events AND catastrophic events play a role in evolution
16
Q
georges cuvier
A
animal anatomist, studied fossils
17
Q
what was cuvier among the earliest to recognize
A
fossil forms were likely extinct
18
Q
why was this idea of fossils forms being extinct a hard concept to grasp
A
didn’t match the ideas of the day that all organisms were part of the ‘great chain of being’,
19
Q
great chain of being
A
scale/ladder of nature created by god
20
Q
what did jean-baptiste pierre antoine de monet, chevalier de lamarck do
A
developed theories of phenotypic evolution and speciation
21
Q
was lamarck correct
A
nah
22
Q
define lamarck’s theory of phenotypic evolution
A
inheritance of acquired characteristics —> traits acquired during the course of an individual’s lifetime were passed on to offspring
23
Q
example lamarck’s theory
A
lengthening of giraffe’s necks over lifetime would be passed down, or thickening of blacksmith’s arms
24
Q
inheritance of acquired characteristics
A
changes in individuals within a generation passed onto next generation
25
natural selection
variation among individuals, certain variants more likely to survive and pass traits onto next generation
26
lamarck's theory of speciation
species originate by spontaneous generation, have not originated from common ancestors
27
who was pre-darwin
plato & aristotle, james hutton & charles lyell, georges cuvier, lamarck
28
when was Darwin
1859
29
who was darwin
1809-1882, voyage of the beagle, accomplished naturalist
30
what inspired Darwin
Thomas Malthus's that argued rate of human pop growth is higher than rate of increase in food supply, leading to famine
31
what did malthus inspire darwin to think
inspired his ideas about struggle for existence
32
when did darwin read malthus
1838
33
describe process of publishing origin of species
after formulating his theory, spent 20 yrs trying to sort out flaws, then finaly published it
34
when did he publish origin of species
1859
35
why did he take a long time to publish origin of species
b/c he knew it would be controversial
36
two major theses of origin of speceis
1. descent w/ modification (evolution), 2. causal agent of evolutionary change (natural selection)
37
describe the process of nat selection as a cause of evolution through generations
early in gen 1: heritable/genetic differences in phenotype
later in gen 1: natural selection acts
generation 2: evolutionary change via natural selection
38
how are the peppered moths example of nat selection/evolution
variation in phenotype, traits are heritable, etc.
39
what is the variation in phenotype
melanic and non-melanic peppered moths
40
describe these phenotypic traits
heritable; have a genetic basis
41
describe peppered moths
white form; soot from coal burning caused black form to be popular, then white form became popular after coal burning decreased
42
what is suggested agent of selection w/ peppered moths
predation by birds
43
descent w/ modification
describes biological evolution
44
natural selectoin
differential survival or reproductive success of classes of entities that differ in one/more characteristics
45
criteria for natural selection
differences, that are inherited (must be inherited for evolution by natural selection)
46
1st component of darwin's book
evolution
47
what is evolutoin
characteristics of lineages of organisms change over time
48
what is 2nd component of darwin's book
common ddescent
49
what is common descent
all life could be portrayed as one great family tree (tree of life, a metaphor
50
was common descent a new or old view of evolution
radically new
51
what is 3rd component of darwin's book
gradualism
52
what is gradualism
proposition that differences b/w radically diff organisms have evolved incrementally, small steps thru intermediate forms
53
what is 4th component of Darwin
population change
54
what is population change
thesis that evolution occurs by changes in the PROPORTIONS of individuals within a population that have diff inherited characteristics b/c of differential survival and reproduction (natural selection)
55
what is 5th component
natural selection
56
what is natural selection
darwin; changes in proportion of individuals w/ diff characteristics are caused by differences in their ability to survive and reproduce; such changes result in evolution of adaptations
57
who independently conceived natural selection
Alfred Russell Wallace
58
was evolution a new theory
no
59
was common descent a new idea
yeah
60
was gradualism (slow incremental change) a new idea
yeah
61
what are adaptations
traits that improve an individual's chance at survival and reproduction in a given env.
62
what was the Darwinian view of evolution
variation is adaptive, natural selection acts on that variation
63
describe pre vs. post darwinian view of variation
before they would see this variation as imperfection; Darwin & Wallace would say the variation is adaptive, natural selection acts on this variation
64
who was Wallace
british naturalist, traveled the world collecting specimens; came up w/ same idea as darwin: Evolution happens thru natural selection
65
what did wallace spur darwin to do
publish origin of species
66
what was wallace called
father of biogeography
67
wallace's line
major biogeographic barrier b/w australasia and asia
68
wallace effect
explanation for speciation via 'reinforcement'
69
what is biogeography
subfield of evolutionary biology; field that focuses on geographic distributions of organisms
70
what's up w/ Wallace's line
barrier, noticed that many groups of organisms were only found north or south of the line
71
basically what is wallace's line a barrier of
barrier b/w australasia fauna
72
what's up w/ wallace effect
natural selection can contribute to reproductive isolation of incipient species (recently derived species) by creating barriers to breeding and geneflow b/w populations and ultimately leading to speciation
73
was darwin's theory accepted or controversial
initially very controversial
74
when was idea of evolution by common descent accepted
1870s
75
was the cause of evolution accepted
no, debated the idea that nat selection caused evolution
76
how long after publication of Origin was the idea of nat selection rejected
60 years
77
what did this rejection of nat selection lead to
rise of mutationist theories
78
what are mutationist theories
argued that discretely diff organisms arose via mutation, nat selection was not required for origin of new species
79
what was mutation seen as
an alternative to nat selection
80
basically sum up idea of evolution and how it was accepted during that time
evolution was a fact at that point, but the theory/explanation wasn't agreed upon
81
richard goldschmidt's idea
'hopeful monsters'
82
what was goldschmidt's idea
sudden drastic changes reorganize the heritable material in an organism ,create new species "hopeful monsters"
83
what would creation of hopeful monsters lead to
most of this massive genetic change would be deleterious, individuals wouldn't survive, but some would
84
what would some individuals surviving lead to
diversification
85
basically sum up richard's idea
sudden, drastic changes create new species --> hopeful monsters
86
another way to describe goldschmidt's idea
macroevolution through macromutation
87
was richard's hopeful monsters idea true
no, didn't pan out
88
what was an important cornerstone to Darwin's theory
heritability
89
but what was a big gap in his theory
heritability of traits; didn't know how to explain that
90
who helped fill in this gap
gregor mendel; did pea experiments, figured out inheritance of phenotypic characters
91
what was big gap in darwin
we know traits were inherited, but no one knew HOW traits were inherited (DNA, etc.)
92
evolutionary theory after Darwin
mendelian genetics
93
what was mendel's idea
particulate inheritance
94
when was mendel's idea published
1865
95
what were evolutionary theories after Darwin
mendel
96
when was Mendel's ideas actually listened to
published in 1865 (around time of origin of species), ignored until modern synthesis
97
when was modern evolutionary synthesis
1930s and 40s
98
what was modern evolutionary synthesis
'revolution', contributions of geneticists, ecologists, systematists, paleontologists
99
what did modern synthesis do
combined Darwin's theory w/ facts of mendelian genetics
100
chief principle of modern synthesis
adaptive evolution is caused by natural selection on mendelian genetic variation
101
what is neo darwinism
adaptive evolution is caused by nat selection on mendelian genetic variation
102
major players of modern synthesis
ronald a. fisher, j.b.s. haldane, sewall wright
103
what did fisher, haldane, and wright do
developed a mathematical theory of population genetics, showed that mutation & natural selection together cause adaptive evolution
104
what is mutation in terms of nat selection
mutation isn't alternative to nat selection, but rather raw material
105
what did those three create
field of population genetics
106
what is example of genetic drift
founder effect
107
what is founder effect
OG population is 50% red 50% green. a subset of them go to an island, forming a founding population. founder effect, radom sampling of OG population leads to diff. proportion of phenotypes % genotypes. now it is 20% red, 80% green.
108
what does random sampling effect cause
genetic drift
109
what is random sampling & genetic drift one way of
one way genetic drift causes evolution (AKA change in gene frequencies)
110
another big player in modern synthesis
Ernst Mayr
111
3 major contributions of Mayr
biological species concept (BSC), theory of geographic (allopatric speciation), theory of founder effect speciation
112
what is BSC
species are groups which are reproductively isolated (don't exchange genes) from other groups
113
2 ways for a diverging species to become reproductively isolated
premating and postmating isolating mechanism
114
premating isolating mechanism
phenotypic preference such as preference for similar coloration or specific display
115
post-mating isolating mechanism
infertility, inviability of hybrid offspring
116
theory of geographic/allopatric speciation
new species form when populations become geographically isolated, thus can undergo genetic divergence
117
theory of founder effect speciation
drastic reductions in population size promote speciation (e.g. 'genetic revolutions')
118
4 major causes of evolution within species
mutation, geneflow/migration, nat selection, genetic drift
119
what happens over long periods of time to these microevolutionary processes
these microevolutionary processes account for origin of new speices and ultimately macroevolution, major evolutionary change
120
what is mutation
creation of new variants
121
what is geneflow/migration
movement of genes or variants of genes
122
what is nat selection
differential reproductive success of phenotypic variants
123
what is genetic drift
random effects such as founder events leading to sampling of alleles in populations causing changes in gene frequencies over time
124
1st fundamental principle of evolution/major tenet of modern synthesis
phenotype (observed characteristics) is different from genotype (set of genes in an individual's DNA)
125
what is phenotypic difference can be from
partly from genetic differences, partly from direct (within generation) effects of environment
126
what is 2nd principle
heredity of variation is based on 'particles' / genes that retain their identity as they pass thru generations
127
3rd principle
evolutionary change is a population level process that entails changes in proportions/frequencies of individual organisms w/ diff genotypes
128
4th principle
genes mutate at a low rate, too low to cause a population to shift from one genotype to another
129
how do population shifts mainly occur from
random fluctuations (genetic drift) and nonrandom changes (nat selection)
130
5th principle
even a slight amount of selection can bring about substantial genetic changes; thus selection can account for both slight AND extreme genetic differences
131
6th principle
mutations can accumulate in populations, thus populations harbor genetic variation
132
can mutations accumulate in populations
yeah
133
do populations harbor genetic variation
yeah
134
7th principle
differences between populations & species are often adaptive (evolved due to natural selection), and are based on differences at several or many genes of small effect (evolution occurs by small steps)
135
what does adaptive mean
evolved due to natural selection
136
describe differences b/w populations and species
adaptive
137
how does evolution occur (big or small steps)
small steps
138
8th principle
species are characterized by barriers to genetic exchange and interbreeding (reproductive isolation), and usually evolve in geographic isolation
139
reproductive isolation
barriers to genetic exchange and interbreeding
140
9th principle
all organisms form a great 'tree of life' of phylogeny; all forms of life have descended from a single common ancestor in remote past
141
example of biology since modern synthesis (1950+)
discovery of DNA
142
who discovered structure of DNA
watson and crick and rosalind franklin
143
when did watson and crick discover DNA
1953
144
what is the biochemical mechanism of inheritance
DNA
145
molecular evolution
analysis of processes and history of changes in genes
146
basically what was an important revolution in biology and evo bio
discovery of DNA, ability to unlock its secretes
147
what is new field in evolutionary biology
molecular evolution
148
what were leaders of modern synthesis called
adaptationists
149
what did adaptationists argue
almost all features of organisms were adaptive and evolved via natural selection
150
what did the molecular evolution 'revolution' do
changed this idea
151
was ernst meyer an adaptationist
yea; was a leader of modern synthesis
152
what did molecular evolution lead them to realize
not everything is driven by selection
153
what did Motoo Kimura do
published Neutral Theory of Molecular Evolution
154
what does natural selection require to act on
requires phenotypic variation to act upon
155
but what actually happens w/r to genetic changes
many genetic changes don't actually cause phenotypic change/variation
156
what was Kimura's hypothesis
most DNA evolution occurs by genetic drift rather than natural selection
157
wobble position
mutation at 3rd position won't change the AA, so won't change the phenotype
158
what happens if theres a mutation at wobble position
won't change the protein, essentially silent change
159
silent changes
natural selection can't see these changes, cuz they don't cause change in phenotype
160
if there's a mutation in that site will it change phenotype of organism
no
161
what does most DNA sequence evolution happen thru
genetic drift (random sampling events) rather than natural selection
162
does most DNA sequence evolution happen thru natural selection
nah, genetic drift
163
but how can u compare DNA sequences
compare proportion of synonymous DNA changes that don't change AAs, to non-synonymous ones that do change AAs
164
what did this comparison provide a foundation for
foundation for detecting natural selection on DNA sequences
165
who were important players in the field of sociobiology
william D. hamilton, robert trivers
166
what was another important piece of post-modern synthesis era
focused on evolution of sociality on behavior
167
what did evolution of sociality on behavior include
ideas about confusing altruistic behaviors and eusociality and conflict in nature
168
what did sociobiology focus on
issues like evolution of social behavior
169
what is confusing altruistic behavior
kin selection; why do individuals help each other, what does that have to do w/ natural selection
170
what does new age of genomics and phylogenomics lead to
insights into size, organization, structure of genomes from terabytes of data and billions of reads of DNA sequence data
171
what does this information yield insight into
causes & consequences of evolution, genetic basis of adaptation
172
what else does data lead to
opportunities for reconstructing robust tree of life to understand evolutionary history
173
how do we study evolution
we infer evolutionary history and its causes, by making predictions and matching those to observed data
174
how do we study macroevolution
comparing data (like variation in genes) w/ theoretical models (HW EQ)
175
what is microevolutionary scale
comparing variation in genes to theoretical models like HW equilibrium
176
what is macroevolutionary scale
paleontology, comparative biology, phylogenetics
