5. allopatric speciation

ALLOPATRIC SPECIATION 1

• takes place when populations are physically or geographically isolated

• scientists recognise this as the main evolutionary process

• important is history of evolution, as great land masses moved and separated

• physical isolation of populations still happens now bc of natural changes

ALLOPATRIC SPECIATION 2

• some changes that result in allopatric speciation are bc of human interventions (e.g. dams, roads, cities)

• ENDEMIC- when species evolves from geographical isolation and is found in only 1 place (Madagascar)

ADAPTIVE RADIATION

• often linked to allopatric speciation

• takes place when 1 species evolves rapidly to form a no. of diff species, which all fill diff ecological niches

• e.g. Darwin’s finches

DARWIN’S FINCHES

• adaptive radiation

  • the og finch species on the islands evolved rapidly into many diff species that each occupied a diff feeding niche

• natural selection

  • og finch species will have shown genetic variation due to mutations- diffs between individual meant they favoured diff niches

• evolving rapidly into diff species occupying diff niches avoid competition for food