founder effect

Question 1

The Founder effect occurs when

Answer 1

only a small number of individuals from a large parent population start a new population

Question 2

As the new population is made up of only a few individuals from the original population only some of the total alleles from the parent population will be

Answer 2

present

In other words, not all of the gene pool is present in the smaller population

A gene pool is the complete range of DNA sequences (alleles) that exist in all the individuals of a population or species

Question 3

Which alleles end up in the new founding population is completely up to chance

As a result, the changes in allele frequencies may occur in a different direction for the new small population vs the larger parent population

Question 4

Example

Answer 4

The founder effect in lizards
Anole lizards inhabit most Caribbean Islands and they can travel from one island to another via floating debris or vegetation

The individual lizards that arrive on an island, as well as the alleles they carry, is completely up to chance

They may only carry a small selection of alleles, with many more alleles present in the lizard population on the original island

The lizards on the original island could display a range of scale colours from white to yellow and the two individual lizards that arrived on the island have white scales

This means that the whole population that grows on that island might only have individuals with white scales

In comparison, the original island population has a mixture of white and yellow scaled individuals. This difference between the two populations is completely due to chance