Speciation slide show

types of Speciation

• Allopatric speciation (geographic barrier, lake, rivers, mountains, sea)
• Sympatric speciation (genetic difference, temporal barrier, pre zygotic barriers)
• Instant speciation (sympatric speciation, non dysjuction, good for plants, allopolyploidy)
• NZ environment, Zealandia

Polyploidy

• Instant speciation
• Triploidy-an extra set of chromosomes
• Octoploid-8 complete sets of chromosomes in a single cell
• Benefits for plants:
• Speciation/frmation of new species within one generation
• Vigourous
• Bigger fruits
• Less susceptible to pests and harsh environment, more likley to survive to reproduction, passing on favourable alleles to the next generation.
• Non disjuction keeps happening until the hybrid is fertile ("solves" post zygotic barrier of hybrid sterility).

What is non dysjunction?/The process

Zealandia continent

Allopatric speciation-how it works

sympatric speciation

Climatic 'islands'

changes in sea level

example of gradual sympatric speciation

• example of the fishes