Q1: Courtship, Sympatric Speciation Flashcards
Speciation
The evolution of new species from existing ones.
Species
A group of individuals that have a common ancestry and so share the same genes but different alleles and are capable of breeding with one another to produce fertile offspring.
How are different species separated?
Reproductively separated
Two types of speciation
Allopatric
Sympatric
Sympatric speciation
Population in the same becomes reproductively separated.
Example of sympatric speciation
Maggot fly
Isolation mechanisms
6
Geographical Ecological Behavioural Mechanical Gametic Hybrid sterility
Geographical isolating mechanism
Populations are isolated by physical barriers such as oceans, mountain ranges, rivers.
Ecological isolation mechanism
Populations inhabit different habitats with the same area and so individuals rarely meet.
Temporal isolation mechanism
Mating is preceded by courtship,
Courtship stimulated by colour, marking, call or actions,
Mutations cause variations in these patterns
Mating doesn’t occur
Gametic isolation mechanism
Genetic or biochemical incompatibility prevents gametes from meeting.
Mechanical isolation mechanism
Anatomical differences may prevent mating occurring.
Hybrid sterility isolation mechanism
Hybrids formed from the fusion of gametes from different species are often sterile because they can’t produce viable gametes.
Members of the same species have similar or the same genes and therefore…
Resemble one another physically and biochemically.
Physical and biochemical resemblance I’m a species helps them to…
Distinguish members of their own species from those of other species.
