environmental variation

variation among individuals is sometimes due to differences in the environment

evolutionary/phylogenetic tree

models the process of evolution as a branching tree w/ a common trunk balances that split off

descent w/ modification

evolutionary changes that have accumulated over time since 2 groups split from each other

nodes

points where one species splits into 2

genetic variation

when genetic material is transmitted from the parents to offspring

evolution

a change in the genetic makeup of a population from one generation to the next

root

the base of the tree, representing the common ancestor of all the groups

selective pressure

describes the full set of environmental conditions, both biotic and abiotic, that allow some organisms to survive and reproduce better than others

natural selection

how population changes over time, but also how they become exquisitely adapted to their environment

tree of life

evolutionary tree of all organisms and has three major branches: bacteria, archaea, eukaryotes

alleles

different forms of a gene

disruptive selection

operates in favor of extremes and against intermediates

dirctional selection

leads to a change in a trait in a population overtime

stabilizing selection

acts against extreme phenotypes and favors intermediate phenotypes

new mutations

harmful and eliminated by natural selection, NO long term evolutionary impact

neutral mutations

does NOT affect survival and reproduction

beneficial mutations

common and result in adaptation to the environment

convergent evolution

process where 2 different species evolve similar traits in response to similar selective pressures

vertebrates

animals like us that have skulls

entomologist

a scientist who studies insects

biodiversity

biological diversity

1st darwin postulate

members of a species vary from one another

2nd Darwin Postulate

some phenotype variation is heritable or passed on to the next generation

3rd Darwin postulate

states that in nature, organisms frequently compete for resources

4th Darwin Postulate

states that variations that increase survival and reproduction will be passed on to individuals in the next generation

intra-sexual

sexual selection focuses on interactions between 1 sex

inter-sexual

selection focuses on interactions between male and females

sexual selection

form of selection that promotes traits that increase an individuals ability to find and attract mates

fitness

ability of an individual to survive and reproduce in the environment in which it lives

on the origin of species

book that brought evolution, natural selection, and adaption to public attention

artificial selection

process where humans select for traits

adaptations

traits of organisms that closely fit their environments