Inheritance and Selection

Question 1

Define geographical isolation and give examples

Answer 1

Geographical isolation occurs when a physical barrier prevents two populations from breeding with one another.
These barriers include oceans, rivers, mountain ranges and deserts

Question 2

Explain how geographical isolation leads to speciation for species X in a forest habitat

Answer 2

• Individuals of species X form a single gene pool and freely interbreed
• Climate changes lead to drier conditions which separate the forest area into two regions, many kilometres apart where region A is colder and wetter whereas region B is warmer and drier.
• In each region, phenotypes are selected which are better adapted
• The type and frequency of alleles in each group become increasingly different
• In time, the differences between the gene pools become so great that they are, in effect, separate species

Question 3

Define speciation

Answer 3

Speciation is the evolution of new species from existing species