BIOL 3301 CH 5

Adaptation

how well organisms respond to change in their environment

1835

when did Charles Darwin find and start studying the Galapagos islands

All org. come from ancestors

what did Darwin find out on the islands he went to

Gradual

was there a gradual or extreme change between organisms from island to island

Economist

who was Thomas Malthus

Better resources

what did good economic times mean

Some species have competitive advantages due to favorable characteristics

what did Darwin theories after he read Thomas malthus work

Darwin’s theory of natural selection 1 step

organisms produce same organisms

Darwins theory of natural selection step 2

chance variation between species, some heritable

Darwins theory of natural selection step 3

more offspring produced that can survive, losers lose and winners win

Darwins theory of natural selection step 4

some physical and behavioral traits have higher chance of survival

Peas

what did Gregor Mendel study

Alleles

exist in alternate forms

Expression of others

what do some alleles prevent

Temporal variation does what

change over time

Temporal

rate and intensity important factors, history influences evolution

Spatial variation

something isn’t uniform but differs when you move from one place to another

Spatial variation does what

main influence on distributions, allows adaptive radiation

Temperature, precipitation, sunlight, predation level

environmental conditions that show continuous variation

Phenotypic plasticity

genotype give rise to different phenotypes under different environmental conditions

Darker

insects from cooler climates

Lighter

insects from hotter climates

Phenotypic trade offs

adaptations advantageous in one environment but handicapper in others

Plastic phenotype

allows you to be fine in either environment which means it has higher excitability

Regulatory

short term, change physiological rates and behavior, utilize existing adaptations and morphology

Acclimation

long term physiological or morphological, reversible

Developmental

slow change, genetic or morphological change, irreversible

Acclimation change

what has a shift regulatory response and handicap organisms at normal conditions

Ability to acclimate

depends on evolutionary history and range of previous acclimation and development

Adapt or adjust, leave, die

what do organisms facing a changing environment do

Microhabitats

move to different areas depending on how your feeling

Migration

seasonal or regular movement of animals from one region to another with return

Dispersal

one time movement away from an area

Energy storage, protect parts

what do animals do when movement is not possible

Dormancy

conditions which organisms dramatically reduce their metabolic processes

Torpor

temporary condition of lowered body temperature and inactivity

Hibernation and estivation

examples of torpor

Hibernation

winter torpor

Estivation

summer torpor

Estivation in animals

arid regions, avoid effects of drought through period of dormancy

Gene pool

sum of all genetic information across all individuals in a population

Allele frequency and genotype frequency

how are gene pools measured

Genotype

combination of two different alleles

Random (independent) assortment

chromosomes distribute to gametes independently, creates new combination of chromosomes in gametes

Recombination

crossing over( chromosomes line up in meiosis), new combination of existing genes on a chromosome

Mutations

new genes, create variation

Phenotypic evolution

change in mean or variance of phenotype of a trait across generations, from allele frequencies

Allelic frequency

the relative frequency of an allele (a variant form of a gene) within a population, calculated by dividing the number of copies of that allele by the total number of all copies of that gene

Selection

certain phenotypes are favored to survive and reproduce over other phenotypes

Natural selection

organisms with traits better suited to their environment are more likely to survive, reproduce, and pass those advantageous traits to their offspring.

Sexual selection

natural selection arising through preference by one sex for certain characteristics in individuals of the other sex

Artificial selection

the process where humans deliberately breed organisms with desirable traits to produce offspring with those same traits

Stabilizing selection

impede changes in a population by acting against extreme phenotypes and favoring average phenotypes

Directional selection

changes in phenotypes by favoring extreme phenotypes over other phenotypes in the population

Disruptive selection

creates bidodal distributions by favoring two or more extreme phenotypes over the average phenotype in a population