Origin Of Species

Front 1

Prezygotic barriers

Back 1

prevent mating between species before formation of zygote

Front 2

habitat isolation

Back 2

two species live in same area occupy different habitats

Front 3

temporal isolation

Back 3

2 species breed @ different times

Front 4

behavioral isolation

Back 4

courtship rituals and behavorial signals are specie soecific

Front 5

mechanical isolation

Back 5

anatomical incompatiblity

Front 6

gametic isolation

Back 6

gametes fail to fuse, sperm cannot penetrate membrane of egg

Front 7

postzygotic barriers

Back 7

prevent from developing viable fertiel adult

Front 8

reduced hybrid viability

Back 8

zygote fails to survive embryonic development

Front 9

reduced hybrid fertility

Back 9

hybrid individual is sterile, inability to produce normal gametes in meiosis. horses and mule make sterile donkey.

Front 10

hybrid breakdown

Back 10

hybrids are viable and fertile, but offspring are feeble or sterile. grasses are weaker.

Front 11

morphological

Back 11

physical characteristics

Front 12

how to identify species?

Back 12

based on morphological, paleontological, ecological, phylogenetic, pluralistic. different definitions

Front 13

ecological

Back 13

the rold organisms play and resourves they use in specific environments. chain.

Front 14

phylongenetic

Back 14

evolutionaray lineages, molecular sequences.

Front 15

biological species concept

Back 15

popuation who has potential to interbreed and produce viable, fertile offspring. reproductively compatible. hardest to determine.

Front 16

allopatric speciation

Back 16

geographic isolation interrupts gene flow. rivers change course, water level lowered, crack in mountain. different mutations and pressures for selection arise.

Front 17

sympatric speciation

Back 17

speciation in geographically overlapping populations.

Front 18

polyplodiy

Back 18

extra set of chromosomes, mutations from meosis. autopolyplod maybe sterile but can reproduce asexually. wheat, grass, tobacco, put in extra, desired chromosomes.

Front 19

evolution of reproductive barriers example

Back 19

starch and maltose flies cannot interbreed. breed with same kind.

Front 20

adaptive radiation

Back 20

diversely adapted species from common ancestor when introduced to new environment and challenges. galapogos and hawaiian islands.

Front 21

punctuated equilibrium

Back 21

leaves no fossil record. species appear suddenly

Front 22

phyletic gradualism

Back 22

speciation occurs gradually. can trace divergence points.