Midterm 1 Flashcards
(135 cards)
1
Q
Anthropology
A
study of humans
cultural, archaeology, linguistic, biological
2
Q
biological anthropology
A
what makes us humans?
3
Q
Great Ape Phylogeny
A
phylogeny of apes - shows last common ancestor is 5 million years ago
phylogeny: evolutionary tree - closer they are, closer related
4
Q
comparative approach
A
compare humans to other species
5
Q
Why do humans smile (SBT)?
A
in despotic: SBT when there is a threat
in egalitarian: SBT in many contexts
power emancipation hypothesis
6
Q
power emancipation hypothesis
A
human smiling indicated egalitarian hierarchy in evolution
7
Q
our approach
A
observe, question, hypothesize, predict, test
8
Q
convergent evolution
A
same trait evolves seperately
9
Q
properties of science
A
data driven, things aren’t proven, constantly updating/self correcting, not authoritative
facts = laws, big ideas = theories
10
Q
evolution
A
change over time
10
Q
homology
A
similar structure due to common descent
anatomical evidence for evolution
11
Q
Genetic Evidence for Evolution
A
DNA/RNA is universal
11
Q
vestigal organs
A
structures from past ancestor that is unused
ex: goosbumps: reaction to being aroused
ex: whale skeletons: hip bones
12
Q
Fossil Evidence for Evolution
A
find traces/fossils of species that used to exist; ancestors of species w/ different features suggests change
fossils of humans: sahelanthropus tehadensis, transitional fossils
12
Q
mistakes and imperfections
A
show built on pre-existing structure
jury rigged design
ex: baggage of bipedalism, appendix, impacted moalrs
12
Q
jury rigged design
A
animals aren’t machines - work w/ what’s available
13
Q
Evolution is Predictive
A
origin of tetrapods - able to find when it should have lived (375 mil) - found tiktaalik
14
Q
Carl Linnaeus
A
systema nautrae (1735) - organized life into categories
insisted humans are primates & shared simmilarities; taxonmic system
15
Q
natural theology
A
18th century belief of human origin; special creation from God & perfectly adapted
16
Q
18th century biology
A
branch of theology
had to swear on 39 articles and study religion
17
Q
William Paley
A
life is well adapted, so God must be the designer
more detailed science - greater glory to creator (humans = best)
how happened
18
Q
Lamark
A
evolution via the inhertiance of acquired characteristics
big mistake is acquired!
what happened
19
Q
Charles Lyell
A
uniformitarianism: idea that world changes slowly and constantly
what happened
20
Q
18th century evidence of evolution
A
fossils existed
21
Charles Darwin
wealthy; went on a voyage (Beagle) and developed the theory of evolution
22
Alfred Russel Wallace
malaria inspired letter with same idea of the theory of evolution
23
Natural Selection
process by which traits become more or less common in a population
| mechanism for evolution
24
4 postulates of natural selection
competition, variation, reproduction, inheritance
25
competition
resources are limited, not everyone survives to reproduce + overreproduction is a threat
26
variation
individuals are different - affects ability to compete & survive
27
reproduction & inheritance
traits are passed from parent to offspring
28
galapogos finches example
Peter + Rosemary Grant:
study finches - beak shape correlate to fallback food
in a drought, change in beak style to process harder seeds
29
adaptive variation
change in response to habitat
30
cross-foster
switch offspring to determine that it is genetic and not learned
31
fitness
ability of organism to survive & transmit gene
32
adaptation
feature shaped by natural selection (survival + reproduction)
33
homology
traits shared by a common ancestor
| go back to common link
34
homoplasy
traits shared due to convergent evolution
| many species can share w/o common ancestor that had trait
35
Non-Adaptive Traits
mutations & incidental by-products
36
mutations
small effect @ population level (most rare and don't work)
more effect when selection relaxed
37
Incidental by-product
have because of adaptation, but isn't an adaptation
example: water birds have penises due to underwater fertilization
females have clitoris as a by-product (same developmental tissue)
38
only mechanism that produces adaptation
natural selection
| does not always lead to evolution
39
behavioral ecology
apply evolutionary theory to behavior
40
What Darwin couldn't explain
why are there showy traits?
why are traits not blended away?
where did new variation come from?
why do we help eachother?
| he did not know genetics
41
Gregor Mendel (mid to late 1800s)
monk who experimented in garden
Garden Pea experiment
father of modern genetics
42
Garden Pea experiment
characteristics had discreet physical forms
seeds: smooth/wrinked, yellow/green
when crossed found that in the first generation (f1), all yellow and round; in the second (f2), mixed
lead to the idea of genes
43
Dihybrid crosses
cross looking @ two traits
44
principle of segregation
inheritance of traits determined by genes passed on - one from mother one from father
| genes don't necessarily show
45
principle of independent assortment
genes for different traits assort independently
46
Mendellian traits in humans
dimples, freckles, earwax
47
Cell Theory (1665-1855)
all organisms are made of cells, the most baseic unit of life
all cells are produced from other cells
48
Rediscovering Mendel (1900)
people did his experiments again and then realized he already existed
49
Chromosomes
small linear body in nucleus
replicated during cell division & creation of gametes
50
Chromosome Inheritance Theory (1902)
sea urchins: sperm + egg have 1/2 of chromosoms of a somatic cell
| wrong number of chromosomes leads to improper development
51
sperm + eggs experiment
when frogs had sex in "taffeta pants" - no tadpoles
confirm that sperm was used in sexual reproduction
52
ploidy
number of chromosmes in a cell (do they have pairs)
53
diploid, haploid, triploid
2, 1 (gametes), 3 - respectively
53
Non Mendellian
linkage, pleiotropy, incomplete dom, co-dom, sex linked, trisomy
54
somatic cells
all cells other than gametes
55
mitosis
diploid parent cell
chromosomes replicated
divide into diploid identical daughter cells
| mitosis
56
meiosis
diploid parent cell
replication (involving crossing over)
divide into haploid gametes
57
Principle of Segregation (genetics)
1 copy of chromosome from each parent
58
Individual Assortment (genetics)
different chromosomes have different genes - independent (esp. bc cross over)
59
allele
gene variants
60
homozygous
AA or aa
the alleles are the smae
61
heterozygous
Aa
the alleles are different
| why not blended???
62
Genotype
combination of alleles in individual
63
Phenotype
observable characteristics (based on dominant and recessive)
64
What happens when you breed two heterozygous
Genotype ratio: 1:2:1
Phenotype ratio: 3:1
65
Crossing over/Recombination
swap info on chromosomes during replication so the two gametes are recombinant types
66
Linkage
some traits on chromosomes ARE linked - greater the closer they are together
| Non-Mendellian Inheritance
67
Pleiotropy
single gene affects multiple traits
| non-mendellian inheritance
68
Incomplete Dominance
two traits "combine"
ex: straight hair + curly hair = wavy hair
| non-mendellian inheritance
69
70
Co-Dominance
traits are both dominant and both appear
ex: black and white feathers
ex: AB blood type
| non-mendellian inheritance
71
Sex-Linked
Y-chromosome is small - cannot trump recessive trait on the X-chromosome
ex: colorblindness: allele on X
in XY, Y cannot overpower, but in XX, other X overpowers (carrier)
therefore, more likely to be a trait in people with XY chromosomes
| non-mendellian inheritance
72
Trisomy
chromosomes don't split in meiosis
ex: extra chromosome in 21 - down sydrome
| non-mendellian inheritance
73
Environmental Implications on Traits
environment can change traits
ex: hydrangea flowers of same genotype have different colors based on soil
| non-mendellian inheritance
74
75
Polygenic
multiple genes code for trait (ex: skin color)
| non-mendellian inheritance
76
genome
all of the genetic material in a cell, including the DNA.
77
double helix
structure of DNA
huge sections are non-coding
allows for replication and inheritance
made of base-pairs: Adenine - Thymine, Cytosine - Guanine
78
Who discovered DNA?
Watson, Crick, and Franklin
79
DNA replication
"unzips" - now has a template due to pairs, and can copy
80
Importance of Proteins
structural: muscle, collagen, keratin
enzymes: affect & allow chemical reactions in the body
regulatory proteins
81
structure of proteins
amino acids into peptides
20 amino acids that go into differnt sequences depending on the code
82
how does DNA code?
DNA is transcipted into RNA which is translated into a protein
the bases combine into 3 letter codons, each of which code for amino acids
DNA transcribed into mRNA (which has U instead of T), which attaches to the ribosome
tRNA brings the amino acids - makes a protein
83
Why are codons repetitive?
reduces the likelihood of a mutation changing something
84
non-synonomous mutation
something changes
85
synonymous mutation
nothing changes
86
gene regulation
some DNA is regulatory
ex:
repressor regions (prevent)
activator regions (turn on)
enhancers (increase rate)
87
Explain Lactase persistence
lactase decreases after waining to conserve energy at a cellular level - sometimes persists
neolithic revolution (12000-6000 ya) - farm + conserve dairy
biocultural coevolution theory
convergent evolution in Europe and Asia
88
pastoralism
cultural practice of milking livestock
89
biocultural coevolution theory
pastoralism coevolved with lactase persistence
both changes reinforced eachother
90
What is the mutation for Lactase persistence?
SNP - change in regulation of lactase
91
biometrics
getting data on human characteristics
| racist undertones/history
92
continuous variation
work of many genes - almost impossible for single gene to control
in many cases, will have a bell curve - show mendellian for each individual gene
93
Population Genetics
change in population over time
natural sellection acts on phenotype but changes frequencies of alleles in the population
94
Evolution causes
natural selection, mutation, migration, genetic drift
95
Population
group of individuals of same species that can interbreed with eachother (big locations or small)
96
Gene Pool
all genes and alleles in a population
look for changes of frequencies in alleles in gene pool - indicator of evolution
96
Genotype Frequency
number with a particular genotype/number of individuals in a population
96
Allele Frequency
copy of alleles/total number of alleles for the gene
97
Hardy-Weinberg Principle
allele proportions constant if no evolution
p = frequency of A
q = frequency of a
p+q = 1
q = frequency of (aa) + 0.5(frequency A)
q^2 +2pq + p^2 = 1
if alleles stay consistent, genotype will reach equilibrium
98
When does the Hardy-Weinberg Principle hold?
- large population size
- random mating
- no mutation
- no alleles transferring in or out
- no selection
99
Agents of Evolutionary Change
natural selection, mutation, gene flow, non-random mating, genetic drift
100
direct fitness
number of genomes passed directly to next generation
101
indirect fitness
number of genomes passed via relatives
102
inclusive fitness
number of direct + number of indirect
| natural selection favors
103
inheritance of acquired characteristics
epigenetics
ex: rat licking
methylation stops genes from being transcribed
when not licked, methylated, and don't lick
when licked, non methylated, and lick
not tied to genes
104
how is variation maintained?
mutations and hidden variation
105
microevolution
allele frequency changes within population
106
macroevolution
origin of new taxonomic groups above level of species
107
Peppered Moth
example of microevolution: dark color blended in with soot covered trees in industrial revolution
108
how to connect macro + micro evolution
microevolutions put togeter make macro
109
species
darwin: rhetorical
clustered by genotypic and phenotypic traits
(sometimes can only tell through chromosomal analysis)
110
Biological Species Concept (BSC)
species: can breed and reproductively isolated
111
Barriers to reproduction
- ecological (space)
- temporal (time)
- behavioral (preference)
- mechanical (physically impossible)
- gametic incompatibility
112
Behavioral Barrier
green lacewings: song differences
113
Mechanical Barrier
Drosophila: genital arches differ
Snail shells swirl in same direction
114
Post Zygotic Barriers to Reproduction
- instability (miscarriage)
- hybrid inviability (die before reproduce)
- hybrid stability (offspring cannot reproduce)
- hybrid breakdown (over few generations, die off)
115
Problems with BSC
doesn't apply to fossils, cannot apply to asexual species
116
Ecological Species Concept
reproductive isolation is not necessary
natural selection keeps species distant from onee another (hybrids can't compete as welll)
117
Humans and the BSC
- 7 mil YA: humans and chimps split; 500000 YA: Neanderthals split; 70000 YA: emigrate out of Africa and encounter Neaderthals
- interbreed (modern 2%)
- selection acted against hybrids
118
Speciation
when 2 populations genetically diverge (on node of phylogenic tree)
allopatric and parapatric and sympatic
119
Allopatric Speciation
geographical isolation + natural selection
character displacement pushes traits to both ends
120
Parapatric Speciation
selection + partial geographic isolation
hybrid zones, but natural selection keeps seperate
121
Sympatic Speciation
populations in same place; instantaneous speciation
122
taxonomy
groupings of organisms based on shared characteristics
123
phylogeny
evolutionary relations between species
124
phylogenic tree
branches that show species based on shared morphology
if go to top, share trait
if don't go to the top, extinct
distance: take all the lines and lay flat
125
Why Reconstruct Phylogeny
explains why certain adaptations evolved
126
ancestral trait
present in common ancestor
127
derived trait
arose since common ancestor
128
molecular clock
average rate at which species genome accumulates mutations
