Convergent evolution examples

Convergent evolution examples

Endemic= native to an area

• New Zealand has a high number of endemic species:• 80% of all vascular plants• 70% of all native terrestrial and freshwater birds• All bats• All native amphibians• All reptiles• 90% of freshwater fish

NZ bird species and flightless

• http://terranature.org/flightlessBirds.htm• Due to lack of predators (especially mammals),

many different bird species became flightless. • This is an example of co-evolution as these

distantly related species faced similar selection pressures (longer life, slower metabolism, slower reproduction rate and energy conservation).

• In New Zealand, the ecological niches normally occupied by mammals as different as rodents, kangaroos and moles, were filled by reptiles, insects, or birds. The only terrestrial mammals were three species of bat (of which two survive today).

• Moa and Haast eagle • Lion/ tiger and prey animals

Kakapo and giraffe experience the same niche

• Since human settlement at least 43 (33%)[2] bird species have become extinct, 16 of these since 1840.[3] Under the New Zealand Threat Classification System 153 out of a total of about 200 species are threatened with extinction.[3]

Gigantism and dwarfism

• Due to species being on island isolated from large mammalian predators species some species became larger and smaller.

• This is due to the selection pressures of:• Lack of predators• Food supply

examples

• Giant lemur (1.5 m, 200kg)

• Giant weta • Giant gecko

dwarfism