bio exam 2 vocab Flashcards
1
Q
Founder effect
A
change in allele frequencies that occurs when new population is established
2
Q
Genetic bottleneck
A
when a population is greatly reduced in size, limiting the genetic diversity of the species. often caused by disease/floods/fires/deforestation
3
Q
acclimation
A
change in an individual phenotype that occurs due to change in environment in a lab setting
4
Q
natural experiment
A
Change in conditions enables comparisons of groups, rather than manipulations of conditions by researchers
5
Q
adaptation
A
heritable trait that increases the fitness of an individual in a particular environment
6
Q
fitness
A
ability of an individual to produce survive and fertile offspring
7
Q
Darwin’s 4 postulates
A
- variation exists among individual organisms that make up a population, such as variation and size
- some of the trait differences are heritable
- survival and reproductive success are highly variable, some will die
- subset of individuals that survive best and produce the most offspring is not a random sample of the population
8
Q
artificial selection
A
deliberate manipulation by humans as animal and plant breeding, of the genetic composition of a population by allowing only individuals with desirable traits to reproduce. artificial breeding + struggle to exist = natural selection
9
Q
sedimentary rocks
A
form from sand or mud or other materials, form slowly
10
Q
structural homology
A
similarity in adult morphology - overall shape or appearance of an organism and is component parts
11
Q
developmental homology
A
similarity in developmental structures or processes
12
Q
genetic homology
A
similarity that occurs in DNA nucleotide sequences, RNA, or amino acid
13
Q
vestigal traits
A
reduced/ incompletely developed structure with little/no function but is related to functioning species
14
Q
acclimatization
A
change of phenotype in response to environment
15
Q
extant species
A
those living today
16
Q
fossil record
A
all the fossil that have been found on Earth and described in the scientific literature
17
Q
fossil
A
trace of an organism that lived in the past, bones/branch/shell
18
Q
descent with modification
A
- species change through time
2. species are related by common ancestry
19
Q
Darwin and Wallace
A
evolution by natural selection, natural selection is responsible for evolution, variation was the key, population thinking
20
Q
Lamarck
A
evolution as the change through time, evolution is progressive in producing larger and better species, evolution is inheritance of acquired characteristics
21
Q
Aritisotle
A
scale of nature, sequence of rank in nature based on size and complexity
22
Q
Plato
A
typological thinking, organisms were perfect essences created by God and unchanging
23
Q
typological thinking
A
organisms of species conforms to specific norm, ignores variation
24
Q
population thinking
A
way of thinking that emphasizes the importance of variation among individuals in a population, opposite of typological which ignores variation
25
evolution
allele frequencies that change over time, populations evolve
26
process component
mechanism that produces the pattern of set of observations
27
pattern component
statement that summarizes a series of observations about the natural world
28
theory
explanation for a broad class of observations that is widely supported by overwhelming evidence
29
populations
individuals of the same species live in the same area at the same time
30
gene flow
alleles added/lost through immigration/emigration, makes alleles more similar between populations, restores genetic diversity from inbreeding/genetic drift, can reduce/increase fitness of animals if mated with less/more fit individuals
31
genetic drift
chance disappearance of allies, random allele frequency changes, especially affects small populations, may increase genetic variation by introducing new alleles/may decrease it by removing alleles, random fitness usually reduces average fitness
32
random mating
individuals don't choose mate
33
HWP Assumptions
1. random mating
2. no natural selection
3. no genetic drift
4. no gene flow
5. no mutation
34
Hardy-Weinberg Equilibrium
observed allele frequencies and allele frequencies of HWP match, if not evolution has occurred
35
Genotype Frequencies
p^2+q^2+2pq=1
p^2= dominant homo
q^2= recessive homo
2pq= hetero
36
Allele frequencies
p+q=1
p= dominant
q= recessive
37
Hardy Weinberg Principle
mathematical null hypothesis for study of evolutionary process
38
gene pool
gametes produced in each generation into a single group
39
sexual selection
one sex mates with another sex, leads to changes in allele frequencies and increases fitness, form of natural selection
40
inbreeding depression
decline in average fitness that may take place when homozygosity increases and heterozygous decreases in a population
41
deleterious alleles
alleles that lower fitness in a population
42
genetic variation
the number of relative frequencies of alleles that are present in a particular population
43
ecological/environmental selection
type of natural selection that favors individuals with traits that enable them to survive/reproduce, Natural selection that does not include sexual selection
44
natural selection
occurs when individuals with certain phenotypes produce more surviving offspring than others, violates hwp, natural selection = ecological selection + sexual selection, only evolutionary process that results in adaptation, can maintain/increase/reduce genetic variation mostly decreases, can produce adaption increasing fitness
45
1. Directional Selection
changes average value of trait, change in phenotype changes in one direction, tends to decrease, graph favors a side
46
2. Stabilizing Selection
reduces both extremes of phenotypes, variation is reduces, no change in average value of a trait over time, graph is centered
47
3. Disruptive Selection
increases variation in a trait, eliminated phenotypes of average value and favors those of extreme value, graph is split both ways
48
4. Balancing Selection
maintains variation in a trait, no phenotype has a distinct advantage, graph is centered and spread out, most common are heterozygous advantage and frequency dependent selection
49
Purifying Selection
when deleterious alleles are lowered or eliminated
50
Heterozygous Advantage
heterozygous individuals have higher fitness, commonly in genes involved with immune systems recognized to destroy invading bacteria
51
Frequency Dependent Selection
occurs when certain alleles are favored when they are rare but not when they are common ex.) guppies are favored because of their rare color goes unseen by predators
52
Intersexual Selection
selection of an individual of one sex for mating by an individual of another sex
53
Intrasexual Selection
selection of individuals within a sex,fighting for mates and territory
54
Bateman-Trivers hypothesis
1. ) if female invests a lot into a few eggs, they should protect their investment by choosing a good male. inversely if males invest little in sperm then they should be willing to mate with any female
2. ) if there are an equal number of males and females in a population, then male will compete
3. ) if male fitness is limited by access to mate then any allele that increases a male's attractiveness to a female male competition should increase, meaning sexual selection should act more strongly on males than females
55
Intersexual Sexual Selection: "honest signals" hypothesis
healthiest and best nourished organisms in a population have best phenotypes (ex. colorful beaks and feathers)
56
Sexual Dimorphism
can result from sexual selection, any trait that differs between male and females
57
Pseudogenes are __________.
nonfunctional, vestigial genes
58
transitional
is a trait in a fossil species that is intermediate between those of ancestral (older) and derived (younger) species.
59
fitness trade off
compromise between two traits that cannot be optimized simultaneously
60
genetic correlation
selection on one trait causes a change in another trait
61
misconception 1: natural selection changes individuals
natural selection does not change individuals, variation changes individuals and therefore acts on populations
62
misconception 2: natural selection is "Lamarkian" aka individuals changes because of their environment/ changed traits are passed on
individuals do not change when selected, they produce more. natural selection sorts not changes
63
misconception 3: individuals adapt
individuals do not adapt, populations do. phenotypic changes aren't passed down because no alleles have changed.
64
misconception 4: natural selection is goal oriented
natural selection is not goal oriented, adaptations don't occur because individuals want or need them
65
misconception 5: mutations occur on purpose
mutations do not happen on purpose, they happen randomly due to errors in DNA and may happen to be advantageous during environment changes
66
misconception 6: evolution is progressive (improvement)
evolution is not progressive, complex traits are often lost or simplified over time. evolution does not mean better traits
67
misconception 7: higher and lower organisms
no hierarchy of animals, refute's Lamarck's ideals, organisms do not progress over time they simply adapt
68
misconception 8: natural selection leads to perfection
natural selection most of the time adapts organisms well to their environment but not perfectly
- traits are not always adaptive
- fitness trade offs exist
- traits are genetically constrained
- traits are historically constrained
- traits are environmentally constrained
69
misconception 14: natural selection is the only process of evolution
natural selection is not the only process of evolution, genetic drift/gene flow/ all lead to allele frequency changes over time
70
sampling error
occurs when allele frequencies of a chosen subset of the population are different from those in the total population
71
mutation
ultimate source of variation
random with fitness
essential for evolution
random production of new alleles, increases genetic variation by producing new alleles, random with fitness, most mutations in coding sequences lower fitness, rarely causes changes in genotype frequencies of eukaryotes because it has such a small affect unless combined with genetic drift/flow/selection
72
point mutation
change in a single base pair in DNA, change in nucleotide sequence occurs in DNA that encodes for protein/RNA that codes or regular expression the new allele may result in regulation of expression
73
chromosome level mutation
a change in number or composition of chromosomes, can cause allele to loose their function or create new
74
lateral gene transfer
transfer of genetic information from one species to another
75
speciation
evolution of 2 species from a single ancestor, caused when gene flow is reduced or limited causing isolation
76
genetic isolation
barrier to gene flow isolates 2 populations within a species
77
genetic divergence
genes of two populations of a single species evolve independently of each other, if diverged new species are formed
78
species
evolutionarily independent population or group of populations
79
biological species concept
main criteria for identifying species is the reproductive isolation, reproductive isolation can result from prezygotic isolation and post zygotic isolation
80
prezygotic isolation
prevent individuals of different species from mating due to temporal (time), habitats, and behavior
81
post zygotic isolation
hybrid offspring of matings between members of different species either do not survive or do not reproduce (sterile)
82
morphospecies concept
evolutionarily independent lineages by difference in size, shape, or other morphological features because distinguishing features are more likely to occur if populations are independent and isolated from gene flow
83
polymorphic species
species with differing phenotypes
84
cryptic species
differing traits other than morphology such as bird songs
85
polyploid
created when two species hybridize, individuals can only reproduce with other polyploid individuals, but they cannot interbreed with either parent species. only in plants
86
Allopolyploidy
state of having more than two full sets of chromosomes due to hybridization between two different species.
87
Phylogenetic species
made up of populations that share one or more synapomorphies.The phylogenetic species concept leads to the recognition of many more species, a number of which are not easily distinguishable based on morphology.
88
Sympatric speciation
Sympatric speciation occurs even though populations live within the same geographical area and serves as a source of new branches on the tree of life. Two types of events can initiate sympatric speciation: external events, such as disruptive selection for extreme phenotypes based on different ecological niches, and internal events, such as chromosomal mutations.
89
synapomorphy
a trait that is found in certain groups of organisms and their common ancestors but is missing in more distant ancestors
90
biological species
group of organisms that can reproduce, reproductive isolation between populations, don't produce viable offspring, reproductive isolation=evolutionary independence, not applicable to asexual and difficult to assess if populations don't overlap geographically
91
morphospecies
morphologically distinct populations, widely acceptable, misses cryptic species and subjective
92
systematics
discipline of biology that characterizes the relationship among all organisms on earth
93
taxonomy
practice of describing, naming, and classifying individual species
94
allopatry
populations that are geographically separated
95
allopatric speciation
speciation that begins with geographic isolation, begins with dispersal and vicariance
96
dispersal
the movement of individuals from one place to another
97
vicariance
the physical splitting of a habitat
98
biogeography
study of how species and populations are distributed geographically
99
sympatry
species or populations live in the same geographic area with one another to interbreed
100
niche
describes the range of ecological resources that a species can use and range of conditions it can tolerate
101
autopolyploid
individuals are produced when a mutation results in a doubling of chromosome number and the chromosomes all come from the same place
102
allopolyploid
individuals are created when parents of different species mate and then an error in mitosis occurs resulting in viable non sterile offspring with two sets of chromosomes
103
reinforcement
natural selection for trait that prevent interbreeding among populations
104
hybrid zone
geographic area where interbreeding occurs and hybrid offspring are common
105
hybridization hypothesis
species fuse together or become extinct when hybrids reproduce
