EVE 100

What is Evolution?

Heritable change in populations over time; A genetic algorithm that operates on living organisms.

What is an algorithm

a finite set of well-defined instructions for accomplishing some task which, given an initial state

What are the properties of an algorithm?

Algorithm, Input (substrate), Fitness function (optimality criterion)

Deterministic algorithm

produce the same output for a given input every time

Stochastic algorithm

incorporate randomness, resulting in different outputs from the same input across runs.

What is a genetic algorithm

a method for solving both constrained and unconstrained optimization problems that is based on natural selection. Only knows how well it works, NOT how it works

Heritable

characteristics passed from parents to offspring,

What is a genotype by environment interaction?

the way different genotypes respond differently to the same changes in the environment

Genetic Variation

the diversity of DNA and protein sequences among individuals within a population, providing the raw material for evolution

Reaction Norms

the graph mapping the phenotype produced by a genotype across a range of environmental conditions

Plastic Trait

Same genotype produces different phenotypes in different environments. Has both genetic and environmental variation

Non-plastic trait

A given genotype produces the same phenotype in any environment. Only has genetic variation

What are fitness trade-offs

where an increase in performance, survival, or reproduction in one trait or environment occurs at the cost of reduced fitness in another.

Hardy Weinberg

p^2 + 2pq + q^2

What are the assumptions of the HW Equilibrium?

Random mating, Population of infinite size, Equal viability of genotypes and gametes (= no selection), No mutation, No immigration or emigration

Inbreeding

closely related individuals are more likely to mate than distantly related individuals

Autozygote

An individual that carries two allele that are identical by descent

Homozygote

having two identical alleles at a specific genetic locus, regardless of their origin

Fitness

the probability of survival and reproduction

assortative mating

similar individuals are more likely to mate because they are similar

social homogamy

similar individuals are more likely to make because they are more likely to meet

genetic drift

coalesence

a mathematical process of how alleles sampled from a population may have originated from a common ancestor.

Bottle Neck

sharp, drastic reduction in population size caused by environmental disaster leaving only a small, random assortment of survivors.

Batesian Mimicry

edible species mimics inedible model to discourage predation

Mullerian Mimicry

inedible species look similar to share the cost of educating predators

Genetic Hitchhiking

genes that are physically linked to a positively selected allele to increase in frequency due solely to that linkage

Selective Sweep

A beneficial mutation will drag to fixation the linked neutral mutation

Background Selection

Selection against harmful mutations will also remove linked neutral polymorphisms

Recombination

the process of breaking linkages between beneficial and deleterious mutations, uncoupling their evolutionary fates

Terminal Nodes

currently existing taxa

Internal nodes

their common ancestors (usually extinct)

Branches

indicate shared descent

Root

common ancestor of the entire clade

Bifurication

marks the beginning of independent evolution

Monophyletic Taxa

include all descendants of their last common ancestor

Polyphyletic taxa

includes descendants of different ancestors

Paraphyletic Taxa

include some, but not all, descendants of their last common ancestor

Homology

A hierarchical concept that represent the similarity in structures between different organisms that is inherited from a common ancestor

Autapomorphies

derived characters unique to one taxon

Synapomorphies

shared derived characters. They are the only useful source of phylogenetic information

Symplesiomorphies

shared ancestral characters

Homoplasies

independently evolved characters

What is a phylogenetic tree

a representation that illustrates the evolutionary relationships and shared ancestry among biological species or taxa, based on genetic or physical traits

Principle of Maximum Parsimony

The optimality criterion where the best estimate of the true phylogeny is one that requires us to assume the smallest number of evolutionary changes

Parsimony

a statistical observation used to reconstruct phylogenetic trees by selecting the hypothesis that requires the fewest evolutionary changes

Consensus Trees

used to combine information from different sources and highlight well-resolved and poorly resolved relationships

What is a molecular clock?

a technique that uses the relatively constant rate of genetic mutations to estimate the time when species diverged from a common ancestor

When did homer write the Illiad?

Approx 707 BCE