Lectures 2 & 3: Evolution and Genetics Flashcards
Proximate Causes
Reasons for how be behave that are immediate, physiological, environmental, or neural
Ultimate Causes
Answers to how we behave that are genetic, evolutionary adaptations, or selection pressures
Central Dogma
DNA –> mRNA –> Protein
Duplication, transcription, translation
From Gene to Protein
- Promoter sequence is where RNA polymerase latches onto to produce mRNA (transcription
- Splicing of the mRNA happens (exons are kept, introns are spliced out)
- mRNA is translated to a protein via the ribosome via a start and stop sequence
Gene
Region of DNA that encodes some function (via the synthesis of either RNA or proteins)
Diploid
Having pairs of chromosomes (homologous pairs) (humans except for sex chromosomes)
Chromosome
Genetic book which holds DNA
Allele
One of multiple forms of a gene (blood type A allele, B allele, or O allele, but it is a blood type gene)
Codominance
Both alleles expressed, blood type AB
Meiosis
Cell division that results in gamete cells which contain half the number of chromosomes (haploid)
Recombination
Shuffling of DNA from homologous chromosomes
Coefficient of genetic Relatedness
R: The probability that two individuals share an allele due to recent common ancestry (ranges from 0-1)
Somatic Mutations
Mutations that occur in non-germ line cells (not sex cells); not heritable
Hereditary/Germline Mutation
Mutation in sex cells; heritable but does not affect the parent’s body
Directional Selection
Moves a population with regards to a trait; a trait becomes expressed more or less on average throughout the species after many generations
Darwin’s Principles of Evolution
- Organisms produce more progeny than can survive; there is competition for resources
- Sexual reproduction causes genotype variation
- Genotype variation causes phenotype variation (traits)
- Traits are inheritable
- Environment selects for particular traits over others
Disruptive Selection
Splitting of a population into two extremes. For examples, in a forest there are only very dark and very light tree trunks, so moths have adapted to have one of those two colors from the original moths that had a neutral color that did not allow for camouflage
Convergent Evolution
Development of similar traits in different species due to shared selection pressure; bats and birds, fins of fishes and dolphins, etc.
Homoplasy
Shared trait w/o a recent shared ancestor
Homology
Shared trait due to a shared ancestor
Richard Dawkins
- Writer of “The Selfish Gene”
- Asked what does evolution act on; survival of the fittest…. what?
- Said genes are the units of selection, and that individuals are vessels in which these genes are carried
- Individuals, like sentinel meerkats, can protect their genes by protecting their family who has their genes, and not necessarily by protecting the individual themselves
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Evolutionary Stable Strategy (ESS) Game
- Game proposed b Maynard Smith
- It works as follows:
- Description of how organisms interact and how well they are doing
- A “mutation gene” changes how individuals interact
- We will test if the gene disappears or prospers and if it increased or decreased the state of the individuals
Altruism
2 definitions:
- Behavior that benefits another at a cost to oneself
- Behavior that increases the fitness of another individual while decreasing the fitness of the actor
Examples: Honey bees who sting you to protect the honey in the hive, vampire bats that take care of their sick bats, and ring-tailed lemurs that show communal rearing of offspring
Units of Selection
- Does natural selection select for individual organisms? group organisms? species? genes?
- If individuals are the unit of selection, genes that reduce individuals’ fitness would be expected to disappear
