Book Notes- Darwin and other big ideas Flashcards
1
Q
Evolution
A
change in genetic composition of populations over time
2
Q
Change in genetic composition of populations over time
A
Evolution
3
Q
underlying changes in the genetic makeup of populations drive the
A
origin and extinction of species and fuel the diversification of life
4
Q
understanding of the mechanisms of evolutionary change
A
evolutionary theory
5
Q
Evolutionary theory
A
how life diversifies and how species interact
6
Q
what supports the factual basis of evolution?
A
vast array of geological, morphological, and molecular data
7
Q
the scientific study of how different organisms function and carry out their lives in nature
A
natural history
8
Q
Darwin went on a 5 year voyage on the
A
HMS Beagle
9
Q
Galapagos island observation
A
most animals were endemic (found nowhere else) and most had undergone different and distinctive changes on each island
10
Q
Darwin’s 3 major propositions
A
- species change over time
- divergent species share a common ancestor and have diverged from one another gradually through time (decent with modification)
- changes in species over time explained by natural selection
11
Q
Natural selection
A
the differential survival and reproduction of individuals based on variation in their traits
12
Q
more individuals of most species are born than (blank)
A
survive to reproduce
13
Q
genetic variation contributes to (blank)
A
phenotypic variation
14
Q
population evolves when
A
individuals with different genotypes survive and reproduce at different rates
15
Q
physical expressions of organism’s genes
A
phenotypes
16
Q
specific form of a character
A
trait
17
Q
features of phenotype
A
characters
18
Q
trait at least partly determined by organisms genes
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heritable
19
Q
genetic constitution that governs character
A
genotype
20
Q
different forms of gene exists at locus
A
alleles
21
Q
particular site on chromosome
A
locus
22
Q
sum of all copies of all alleles at all loci found in a population
A
gene pool
23
Q
Evolution can also be defined as
A
changes in the proportions of alleles in a gene pool over time
24
Q
earth = (blank) years old and life has existed for (blank) of those years
A
4.5 and 3.8
25
How do scientists date ancient events?
geological time scale
26
Earth's history is recorded in (blank)
rocks
27
strata
oldest layer of rock
28
stratigraphy
certain fossils are always found in younger strata and certain always found in old (old-bottom)
29
(blank) provide a way to date fossils and rocks
Radioisotopes
30
radioactive isotopes in elements
radioisotopes
31
Radioisotopes
decay in predictable patterns over long periods
32
specific time period- over half of the atoms in a radioisotope decay to become a different, stable isotope
half life
33
formed from materials that existed for varying lengths of time before being weathered, fragmented, and transported, sometimes over long distances to the site of their deposition
sedimentary rocks
34
Radiometric dating of rocks older than 60,000 years requires estimating radioisotope concentrations in (blank)
igneous rock
35
what are the most powerful methods used to construct a geological time scale?
radiometric dating of rocks and fossil analysis
36
relates ages of rocks to patterns in Earth's magnetism
paleomagnetic dating
37
Hadeon eon
time on Earth before life
38
Archean eon
early history of life/ended when photosynthetic organisms 1st appeared
39
Proterozoic eon
prokaryotic life diversified rapidly and first eukaryoes in fossil record
40
Phanerozoic eon
542 mil yr- multicellular eukaryotes rapidly diversified
41
What 3 eons make up the Precambrian
Hadeon, Archean, and Proterozoic
42
What are the mechanisms of evolutionary change?
changes in the genetic makeup of populations over time
43
a group of individuals of a single species that live and interbreed in a particular geographic area
population
44
INDIVIDUALS DO NOT EVOLVE, (BLANK) DO
populations
45
4 additional mechanisms of evolution that affect genetic makeup of populations over time
- mutation
- gene flow
- genetic drift
- nonrandom mating
46
mutation generates (blank)
genetic variation
47
any change in the nucelotide sequence of an organisms DNA
mutation
48
natural selection acts on random variation to produce (blank)
adaptation
49
some alleles may become (blank) if environmental conditions change
advantageous
50
mutation rate can be low and populations can still contain (blank)
large genetic variation
51
sum of the genetic variation in a population
gene pool
52
proportion of each genotype among the individuals in a pop
allele frequency
53
proportion of each genotype among the individuals in pop
genotype frequency
54
calculations of frequencies =
measurement of evolutionary change
55
selection acting on genetic variation leads to (blank(
new phenotypes
56
the purposeful selection of specific phenotypes by humans
artificial selection
57
natural selection vs artificial selection
traits that helped organisms survive and reproduce vs traits preferred by humans
58
a favored trait that evolves through natural selection
adaptation
59
selection for beneficial changes
positive selection
60
selection against deleterious changes
purifying selection
61
gene flow may change (blank)
allele frequencies
62
migration of individuals and movements of gametes between populations
gene flow
63
example of gene flow
neanderthaals and red hair
64
genetic drift may cause large changes in (blank)
small populations
65
random changes in allele frequencies from one generation to the next
genetic drift
66
genetic drift (blank) in small pop
increases
67
environmental conditions that only a small # of individuals survive
population bottleneck
68
example of population bottleneck
hunting and habitat destruction, decrease illinois chickens
69
loss of genetic variation in a small population is a problem for (blank)
endangered species
70
because of its small size, the colonizing population is unlikely to posses all the alleles found in the gene pool of its source population resulting in decrease in genetic variation
founder effect
71
nonrandom mating can change (blank)
genotype or allele frequencies
72
individuals of one sex mate preferentially with particular individuals of the opposite sex
sexual selection
73
traits that enhance reproduction often reduce (blank)
survival chances
74
downfall of sexual selection
survival rate reduced
75
example of sexual selection- frogs
female prefer low frequency calls because it is a sign of survival
76
example of sexual selection- male african long tailed widowbird
females prefer long tails but this means the males can't fly
77
How do biologists measure evolutionary change?
measure evolution by looking at gradual changes in allele and genotype frequencies in populations
78
Evolutionary change can be measured by (blank)
allele and genotype frequencies
79
allele frequency (p) =
copies of alleles in population/ total # of copies of all alleles in pop
80
p + q =
1
81
if there is only one allele at a given locus in a population, frequency = (blank) and the population is (blank) meaning the allele is (blank)
1, monomorphic, fixed
82
frequencies of the different alleles at each locus and the frequencies of different genotypes in a population describe population
genetic structure
83
Evolution will occur unless certain (blank) exist
restrictive conditions
84
model in which allele frequencies do not change across generations, and genotype frequencies can be predicted from allele frequencies
Hardy-Weinberg equilibrium
85
several conditions of hardy-weinberg
- no mutation
- no selection among genotypes
- no gene flow
- population size is infinite
- mating is random
86
2 consequences of Hardy-Weinberg
- frequencies of alleles at a locus remain constant from generation to generation (no evolutionary change)
- genotypes occur at certain frequencies (p2+2pq+q2)
87
Deviations from Hardy-Weinberg equilibrium show that
evolution is occuring
88
Hardy Weinberg is useful for
predicting the approx genotype frequencies of a pop from its allele frequencies
89
Hardy Weinberg model allows biologists to
evaluate which mechanisms of evolution are acting on a particular population
90
Natrual selection acts directly on (blank)
phenotypes
91
Reproductive contribution of a phenotype to subsequent generations relative to the contributions of other phenotypes
fitness
92
Changes in #s of offspring are responsible for increases and decreases in the (blank) of a population
size
93
changes in the (blank) of different phenotypes in a population will lead to changes in allele frequencies from one generation to the next
relative success
94
(blank) of a phenotype is determined by the relative rates of survival and reproduction of individuals with that phenotype
fitness
95
natural selection can (blank) or (blank) populations
change or stabilize
96
show continuous variation
quantitative traits
97
preserves the average characteristics of a population by favoring average individuals
stabilizing selection
98
changes the characteristics of a population by favoring individuals that vary in 1 direction from the mean of the population
directional selection
99
changes the characteristics of a population by favoring individuals that vary in both directions from mean of population
disruptive selection
100
stabilizing selection
reduces variation in pop, but does not change mean
101
example of stabilizing selection
human birth weight
102
directional selection
individuals at 1 extreme, shift avg value
103
example of directional selection
texas longhorns
104
disruptive selection
individuals at opposite extremes contribute more offspring than mean (increases variation)
105
example of disruptive selection
West African Finch Bill size
