Speciation - hard stuff Flashcards
Pre-zygotic RIM
Occur before fertilisation. Prevents the fertilisation of eggs.
Ecological RIM
Pre-zygotic RIM
The existence of a prezygotic barrier between two species as a result of them occupying or breeding in different habitats within the same general geographical area.
Behavioural RIM
Pre-zygotic RIM
- Courtship behaviours are a necessary for successful
mating. - Dances, calls, displays, or the presentation of gifts. The
displays are specific and unique to each species. - - Members of other species do not recognise or pay
attention to these behaviours.
Temporal RIM
Pre-zygotic RIM
Temporal isolation means isolated in time and prevents species interbreeding because they mate or they are active at different times. Different times of the day or seasons.
Mechanical RIM
Pre-zygotic RIM
Structural differences in the anatomy of reproductive organs prevents sperm transfer between individuals of different species.
Post-zygotic RIM
Operate after fertilisation has occurred. Important for maintaining the integrity of closely related species.
Hybrid inviability
Post-zygotic RIM
Mating between individuals of two species may produce a zygote, but genetic incompatibility may stop development of the zygote. Fertilised eggs often fail to divide because of mis-matched chromosome numbers from each gamete.
Hybrid sterility
Post-zygotic RIM
When two species mate to produce a hybrid offspring, but the hybrid is not fertile. The species are still reproductively isolated and genes cannot flow from one species gene pool to the other.
Hybrid breakdown
Post-zygotic RIM
The first generation may be fertile but the second generation are infertile.
