ANT 001 Midterm Flashcards
Anthropology
holistic study of humans requiring time depth
2 Ultimate Explanations
adaptive and phylogenetic
Adaptive explanation
what is the function
Phylogenetic
what is the evolutionary history
Descriptive questions
questions with known answers
Prescriptive questions
questions with unknowable answers
Darwin’s 3 postulates
over-reproduction, individual variation affects success, variation inherited
Directional selection
natural selection favors individuals with traits that differ from the average, changes average
Stabilizing selection
natural selection favors the average, maintains status quo
Balancing selection
natural selection maintains genetic variation by favoring multiple alleles at a locus
True breeding lines
homozygous for a particular trait
Mendel’s laws
particles of inheritance segregate, independent assortment
independent assortment
alleles for different traits are independently inherited
Genes
unit of heredity transferred from parent to offspring
Non-synonymus mutations
mutations have a large effect on proteins
Synonymus mutations
mutations have no effect on proteins
Gene expression
the phenotype that is expressed based on the genotype
Mitosis
somatic cell division with same paired chromosomes
Meiosis
gamete cell division with one of each paired chromosome
Homozygous
two same alleles
Heterozygous
two different alleles
Codominance
heterozygotes have intermediate phenotypes
Linkage
genes on the same chromosome tend to stay together during meiosis
Recombination
chromosomes tangle and break during meiosis and bits can be swapped between paired chromosomes
Hardy-Weinberg relationship
after one generation of random mating an equilibrium for genotype frequencies is reached
Heritability
transmissible from parent to offspring
Plasticity
adaptability of an organism to changes in environment or habitat
Genetic evolution
change in the frequencies of alleles through time
4 Processes of Evolution
natural selection, mutation, genetic drift, gene flow
Mutation
change to DNA sequence
Genetic drift
change in allele frequencies in population that is finite in size
Gene flow
movement of genetic material from one population to another
Fixation
when frequency has reached 100% in a population
Karyotype
number and appearance of chromosomes in cell nuclei
Single Nucleotide Polymorphism
variation in a single base pair in a DNA sequence
Haplotypes
combination of alleles or sequence of SNPs that are inherited together
Selective sweeps
new advantageous mutation eliminates or reduces variation
What does human evolutionary biology address?
how and why we evolved to look and behave as we do
What can natural selection do?
change population average, keep populations the same, lead to loss of variation, sometimes maintain variation
How does natural selection work?
produces complex adaptations through multiple incremental steps
What constrains natural selection?
heritable variation
What do Mendel and Hardy-Weinberg’s laws demonstrate?
variation can be maintained indefinitely with random mating
What happens if non-random mating is used?
change genotype frequencies
What produces continuous variation?
mendelian inheritance when multiple loci affect the phenotype, environmental interaction with genotype
What can natural selection act on?
Single and multiple loci traits, morphology, behavior, and plasticity
What do the neutral evolutionary processes do?
can differentiate populations, mutation and genetic drift tend to balance each other, drift means bigger populations will be more variable
What happened when humans left Africa?
series of founder effects, which resulted in a decrease in within group genetic variation with distances from Africa
Introns
noncoding parts of the RNA transcript
Exons
coding parts of the RNA transcript
What decides a phenotype?
environment + genes (environment X genes)
Where is trait variation typically found?
trait variation is found more within groups than between groups
Why do some traits vary between populations?
natural selection in different ecologies
What does knowing someone’s race NOT do?
give representative information about their genotype or ancestry
Social learning
learning through observation of other people’s behaviors
Cumulative culture
process by which beneficial modifications are culturally transmitted and progressively accumulated over time
Vertical transmission
parent to offspring
Oblique transmission
from other older non- parents
Horizontal transmission
from peers
Social facilitation
observing others increases the chance that individuals will learn the behavior on their own
Emulation
observe and copy end state but not process
Observational learning
individuals learn behavior by observing others
Difference between vertical vs. horizontal & oblique transmission?
vertical transmission typically increase fitness, while horizontal/oblique can reduce fitness
What did cultural capacities do?
- genetically evolved and allowed us to spread across the earth
- allowed behavioral diversification across populations
Can cultural practices influence genetic evolution?
yes
Is there more cultural than genetic variation between groups?
yes
Genetic distance
measure of how different two groups are
Selective sweeps and variation
regions closer to the select locus are expected to be less variable
Why do humans have so little genetic variation compared to great apes?
the human population was a lot smaller fairly recently in the past
Why does within group variation decrease with distance from Africa?
groups further from Africa were the product of founding events and were founded more recently
Why do genetic distances between groups increase with the geographic distances between them?
nearby groups split from each other more recently than far away groups
What are some common misconceptions about race?
few categories, discontinuous variation, correlated with many genetic traits, defining traits are obvious, race = ancestry, permanent categories
Continuous variation
different types of variation are distributed on a continuum (e.g. height, weight)
Discontinuous variation
variation is in discrete, individual categories (e.g. blood type)
How does natural selection produce seemingly harmful traits?
the environment includes others of the same species (sexual selection, cooperation)
Sexual reproduction
two individuals combine their genetic material via the fusion of their gametes
Do males or females have larger gametes?
Females
What is reproductive success based on?
How long an individual survives, getting at least one mate, how many offspring are produced from each mating, whether the offspring survive to adulthood
Strategies
sets of behaviors with a function
Bateman’s principles
- Mating success influences reproductive success in males more than in females.
- Males vary more than females in how many mates they have.
- Males vary more than females in how many offspring they have.
Naturalistic fallacy
genetic/evolved/natural does not necessarily mean “good” in a moral sense
What limits females’ reproductive success?
resources (food, shelter, social support)
What limits males’ reproductive success?
access to females
Intersexual selection
favors traits that make one sex more attractive to others
Intersexual selection
favors traits that make individuals successful in competition with others of the same sex
Phenotypic benefits
traits affecting female survival, offspring survival,
Genotypic benefits
males with “good” genes (color, display, condition)
Arbitrary traits
female preference can co-evolve with arbitrary male traits
What are females interested in regarding mating?
phenotypic benefits, genotypic benefits, arbitrary traits
Contest competition
males increase mating success by preventing other males from mating
Scramble competition
males increase mating success by getting access to females first
Do males or females tend to have higher reproduction variance and stronger sexual selection?
males
