Reproductive Isolating mechanisms

postzygotic isolation

1. zygotic wastage 2. Hybrid sterility 3.Hybrid Sterility 4. Hybrid Breakdown

prezygotic isolation

1.Ecological isolation 2. Geographical isolation 3. Temporal isolation 4. Ethological isolation 5. Mechanical isolation 6. Gametic isolation

ethological isolation

Isolated by behaviors. example lizard, blue footed boobies and the bird of paradise

geographical isolation

Isolated by distance or geographical barriers (lice)

What does reproductive isolating mechanism do ?

Maintains positive adaptations for specific environments

zygotic wastage

Minimum number of zygotes required to give a viable adult

reproductive isolating mechanism

any inheritance feature of body form, function, or behavior that prevents interbreeding between one or more genetically divergent populations

hybrid inviability

fertilized egg cannot develop past early embryonic stages

gametic isolation

games are incompatible with other species resulting in mortality. example pollen. Gametic (eggs or sperm) wastage = minimum number of sperm required. only need 1 to reproduce but in order for one to survive then there has to be 20-40 million sperm.

mechanical isolation

isolated by incompatible reproductive parts - can result in mortality (example testse flies)

Ecological isolation

isolation due to adaptation to different microclimates (oak tree) conserve water

temporal isolation

mate a different times of years (depending on time of resources) (bamboo)

Postzygotic isolating mechanism

mechanism of isolation after fertilization

Prezygotic isolating mechanisms

mechanisms of isolation before or during fertilization

hybrid sterility

no viable sperm or egg

hybrid breakdown

offspring fertile but their offspring sterile