locus that correlates with variation of a quantitative trait in the phenotype of a population of organisms
antagonistic pleiotropy
occurs when a mutation with beneficial effects for one trait also causes detrimental effects on other traits (ex. benefits when we are younger lead to disease when we're older)
intrasexual selection
A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex
Female choice (inter sexual selection)
By being choosy, females act as agents of selection on male phenotypes
Anisogamy
Difference in size/investment into sperm v egg gametes
Operational sex ratio
ratio of males to females capable of reproducing at a given time
sexual selection
competition for access to reproduction
benefits of female choice
higher quality of offspring, food (direct benefit), better genes for offspring (indirect benefit)
Key characteristics of male display traits
Expensive to produce (difficult to fake/cheat)
Conspicuous (easy to see hear/smell)
Highly variable
Carotenoids
yellow/orange/red pigments that animals cant make themselves
many have antioxidant/immune properties
in order to drive speciation sexual selection
needs to have high variability between males
Fisherian runaway selection
No true benefits, just preference (ex peacocks)
Male / male competition
malesbattle for access to females (very costly)
Antagonistic co-evolution
There can be evolutions for the sole benefit of one gender, might be damaging to the other (male-male competition can be detrimental to the female)
How many times was modern corn domesticated?
Once
What happened when civilization arose?
weapons became popular (hunting big animals)
Eating food other than animals (changing landscapes to grow crops)
Artificial selection
occurs when humans preferentially breed individuals with desired characteristics (doesn't always result in higher fitness)
Teosinte
the ancestor of corn (domesticated once with 5 genetic changes)
Is corn a GMO?
Yes, it is the result of thousands of years of artificial selection
What type of selection is fishing?
Negative selection. The prize individuals are being taken out of the population and the remaining fish to breed are less desirable
Bacillus thuringiensis (Bt)
A naturally occurring soil bacterium that produces a protein that kills many pests, including caterpillars and the larvae of some flies and beetles. (Bt crops are organic)
Hox genes
transcription factors that determine the anterior-posterior body axis in bilateral organisms and influence the developmental fate of cells.
how do we know we all descend from a common ancestor?
all animal life is constructed using the same basic molecular "tool kit"
Because regulatory regions are compartmentalized
where and when genes are expressed can evolve, different functions of genes (wing v leg) can evolve independently
3 ways to alter animal phenotypes
1. truncation of a pathway (loss of eyes in cavefish)
2. changing relative rates of gene expression (long bat fingers)
3. expressing/activating a pathway in a novel context (growth of horns on beetle heads using master regulator of limb identification)
polyphenism
multiple discrete phenotypes that arise from a single genotype
Orthologs
genes in different lineages that evolved from a common ancestral gene
paralogs
genes related by duplication within a genome
vicariance event
the formation of geographic barriers to dispersal and gene flow, resulting in the speciation of once continuously distributed populations (micro evolution leads to macro evolution)
biological species concept
species are groups of interbreeding natural populations that are reproductively isolated from other such groups
allopatry
physical isolation of populations
parapatry
physical separation by distance, but populations still exchange genes
Cline
gradient in trait (or genetic) variation across space
sympatry
no physical separation, lots of exchange of alleles
by changing the environment we are altering
the "S" for other species
why do we store crops in cylos/pyramids
minimize oxygen for insects survival
R-species
rapid growth, short life span, lots of young, low investment into young
K-species
Slow growth, long lifespan, few young, high investment per offspring
allocation trade off
when limited resources are allocated to one life history trait at the detriment of another