Grade 11 Evolution

Microevolution

small scale evolution

Macroevolution

large scale evolution, creation of new species

Four fundamentals of evolution

Variation, Inheritance, Selection, Time

Physical Structures Adaption

change in physical body for better survival

Physiological Function Adaption

Change to physical functions/survival mechanisms

Behavioral Pattern Adaption

Change in behavior/social patterns to better survive

Fitness

Measure of how well a species can survive in an environment

Natural Selection 

Environment selecting for organisms

Artificial Selection 

human pressure selecting for specific traits in populations 

fossil records 

study of remains of living things. rare because it requires ideal process conditions 

transitional fossils

remains of species in between the transition of two different species 

geology records

strata layers one on top of the other forming different layers with different fossil types

gradualism

slow constant evolution

punctuated equilibrium

very rapid evolution then same for long periods of time

speciation

the formation of new and distinct species in the course of evolution.

phyletic speciation

species a → species b → species c

divergent speciation

species a → species b & species c

stabilizing selection

lowers population of less common traits, increasing more fit population

directional selection

shifts most advantageous population traits

disruptive selection

lowers population of most fit population, increasing outlier population and possibly allowing new species to form 

sexual selection

non-random, natural selection through mating patterns

female choice selection

males preform for female attention so females will reproduce with them 

male competition 

males fight eachother for access to female harem 

genetic drift 

change in one specific allele frequency due to random chance event, changing genetic variation ratio

bottleneck effect

dramatic reduction on an entire population (typically by natural disaster or human activity )

founder effect

individuals from a population leave to establish new populations

gene flow

individuals migrate between populations allowing for interbreeding

biological species concept

a group of individuals that can successfully interbreed and reproduce healthy and fertile offspring under natural conditions

population genetic concept

species is defines as a group which can interbreed, thereby contributing to the gene pool 

allopatric speciation

species is separated geographically causing isolation and separate evolution

parapatric speciation

evolution of new species from a single population that is spread over a large geographic area, but individuals only mate with their close neighbor

sympatric speciation

species share common ancestor and are not isolated geographically, still evolve separately 

prezygotic mechanisms

reasons for why two species cannot interbreed with one another

postzygotic mechanisms

reasons for why interbreeding cannot occur after mating has happened

ecological isolation

prezygotic - location of specie populations prevent species from coming into contact with one another

temporal isolation

prezygotic - compatible but mating periods/reproductive cycles don’t line up

behavioral isolation

prezygotic - species have different mating rituals

mechanical isolation

reproductive organs are structurally incompatible

gametic isolation

prezygotic - sperm/egg can’t recognize each other

zygotic mortality

postzygotic - embryo is unable to develop to maturity 

hybrid viability

postzygotic - hybrid is unable to live long

hybrid infertility

postzygotic - hybrid is born sterile and unable to reproduce 

divergent evolution

common ancestor gives rise to two or more new drastically different  species 

adaptive radiation 

one species give rise to three or more closely related species 

convergent evolution

two or more species evolve to become similar looking, are affected by same pressures

coevolution

one species evolves in response to another’s evolution and vise versa, relying on eachother

homologous structures  

basic similar arrangement of bones/structure, don’t have to serve the same function 

analogous structures

structures serve the same function but are not built by the same structure

vestigial structure

structures that were once functional but now have no function

embryology

similar stages in embryonic development suggest common ancestry