bio 115 final terms

bionomial nomenclature

Classification system; each species is assigned a two-part name

gradualism

Hutton — theory that evolution occurs slowly but steadily (erosion, volcanism)

uniformitarianism

Lyell — refined gradualism; theory that geologic processes uniform over time

Lamarck's 2 ideas; natural mechanisms for evolution

use and disuse, inheritance of acquired traits

use and disuse

body part used --> larger and stronger

not used --> deteriorate

ex. giraffe neck gets longer

inheritance of acquired traits

acquired traits passed to offspring

ex. giraffe's next gets longer --> passed to offspring

SEQ Darwin

voyage: collected plant/animal specimen. witnessed earthquake in SA, measures the changes

after the voyage: developed theory of evolution by natural selection

Wallace

reached same conclusion as Darwin, presented w him at Linnaean Society

Darwin's 4 observations

overproduction, unequal survival and reproduction, heritable variation, non-random survival and reproduction

overproduction

more offspring born from each gen. that will S+R

heritable variation

indiv have variation, offspring resemble parents; offspring share better adapted traits

nonrandom survival and repro

S+R based on phenotype; best adapted indiv --> R more

descent with modification

pops change over time as beneficial traits increase in frequencies and detrimental traits decrease

evolution by natural selection

better adapted indiv --> greater S+R; survival within pop of traits that promote repro success

evidence for evolution

artificial selection, direct observation, homology, fossil record

artificial selection

Breeding organisms with specific traits in order to produce offspring with identical traits (dairy cows)

direct observation

ex. antibiotics and resistance; bacteria that survives antibiotics reproduce and creates resistant bacteria

homology

similarity due to CA

fossil record

remains or traces of dead organisms in sedimentary rock

population genetics

study of genetic variation within pops and evolutionary factors that act on it

phenotypic variation

observable differences between indivs (have trait or don't)

ways that genetic variation is created

point mutation, changes in chromosome structure, rapid reproduction, sexual recombination

point mutation

one nucleotide changes to another --> new allele made, new pheno

changes in chromosome structure

duplications/aneuploidy generates new variation

rapid reproduction

proks multiply faster --> higher mutation rate per unit time --> more variation

sexual recombo

crossing over, LoIA

population

a group of potentially sexually interbreeding organisms of same species living in the same area at the same time

gene pool

all alleles of all genes in a pop at any given time

allele frequency

portion of a specific allele within a population

unequal survival and repro

some offspring survive longer and R more than others --> competition

fixed allele

all individuals in pop homozygous for same allele — only 1 allele found at a locus within a population

Hardy-Weinberg equilibrium

describes genetics of populations that are not evolving; rare, but provides a baseline for hypothesis testing

HW equation

allows for calculation and genotype frequencies; p + q = 1

HW eq for calculating genotype frequencies

p^2+2pq+q^2 =1

5 conditions required for HW equil.

no mutation, random mating, no selection, very large pop (no gene drift), no gene flow

mutation.

source of variation; have very little effect on allele frequencies, esp in large pops

nonrandom mating

no random mixing of gametes --> inbreeding (increased genetic similarity, due to NS)

natural selection.

selection acts on phenotype, pops must be polymorphic

morphs

contrasting phenotypes (ex. red vs white flowers)

polymorphic

population w 2 or more morphs at detectable frequencies

modes of selection

stabilizing selection, directional selection, disruptive selection

stabilizing selection

selects intermediate phenos, at stable enviro

directional selection

selects for one phenotype extreme

disruptive selection

selection for both pheno extremes, variable enviro

genetic drift

random changes in AF, chance events (cow eats 3/10 random flowers)

special cases of genetic drift

bottleneck effect and founder effect

bottleneck effect

size of pop reduced, survival random; new pop has different AF than orig pop

founder effect

small number of individuals colonize a new habitat; gene pool of new pop different from parent pop

gene flow

movement of alleles between pops; effect of migration

speciation

1 species splits into 2, appearance of new species

biological species concept

Mayr — species if a group of pops whose members have potential to interbreed; share gene pool, gene flow in same species, no gene flow w other species (repro iso)

limits of bio species concept

extant species are dead, can't tell interbreeding

asexual/viruses species don't breed

morphological species concept

species distinguished by shape/structure (applies to everything, but we don't know what features are most important)

ecological species concept

species defined by ecological niche — how individuals interact with environment (only works with extant)

prezygotic isolating mechanisms

habitat, temporal, behavior, mechanical, gametic isolation

habitat isolation

overlapping habitat, don't interact

temporal isolation

overlapping but breed at different times

behavioral isolation

different mating rituals

mechanical isolation

different sexual structures

gametic isolation

no chemically compatible, egg and sperm are different

postzygotic barriers

reduced hybrid viability, reduced hybrid fertility, hybrid breakdown

reduced hybrid viability

hybrid dies before birth

reduced hybrid fertility

hybrid born but sterile

hybrid breakdown

hybrid survives but gens after it are infertile or frail (hybrids can mate with other hybrids)

allopatric speciation

making new species in populations that are geographically isolated from one another

mechanisms for allopatric speciation

migration (founder effect), chance events

sympatric speciation

formation of new species in populations that live in the same geographic area

mechanisms for sympatric speciation

polyploidy, sexual selection, habitat differentiation

polyploidy

changing ploidy due to mutation --> no longer compatible with parent pop --> new species made

sexual selection

selection for different traits in males and females; barrier of repro between subpops --> makes new species

habitat differentiation

subpop uses habitat or resources --> makes new species/habitat isolation

taxomy

science of nameing and classifying organisms.

phylogeny

evolutionary history of a species

nested hierarchy

DKPCOFGS

phylogentic species concept

species are independent lineages

cladistics

classification based on common ancestry

phylogenetics

study of evo history and relatedness of bio entities

root

represents MRCA of all taxa

node/branch point

divergence of 2 lineages from CA

sister taxa

groups of orgs that share immediate CA

basal taxon/outgroup

lineage that diverges early in history, first to diverge from CA

polytomy

branch with more than 2 groups; indicates unclear evo relationship

3 types of phylogenetic groups

mono, para, poly

monophyletic group (clade)

CA + all descendants

paraphyletic group

CA + some descendants

polyphyletic group

distantly related species, excluding CA

shared derived trait

derived traits present in all members of ingroup

2 reasons for similarity

homologous, analogous traits

homologues traits

similar due to CA, included in phylogeny

analogous traits

similar characteristics resulting from convergent evolution and similar enviro pressures

convergent evolution

unrelated organisms independently evolve similarities when adapting to similar environments

proximate causation

"how" a behavior occurs or is modified

ultimate causation

"why" a behavior occurs in the context of natural selection

how stimuli impacts behavior

fixed action patterns, migration, behavior rhythms, communication

fixed action patterns

innate behaviors that follow a regular, unvarying pattern (see orange belly/stimulus --> attack)

migration.

know the way through stimulus (sun, magnetic field)

behavioral rhythms

stimulus is (or lack of) sun — circadian rhythms, circannual rhythms

communication

do mutually recognizable dances/signals to trigger behaviors; the stimulus is the sign from others to start dancing or find food

types of learning

imprinting, spatial learning, associative learning, social learning

imprinting

during sensitive period; response to particular individual that makes noise and moves; irreversible