Genetic drift

Question 1

When a population is significantly small, chance can affect which alleles get passed onto the next generation

Over time some alleles can be lost or favoured purely by

Answer 1

chance

Question 2

How to know if genetical drift is occurring

Answer 2

When there is a gradual change in allele frequencies in a small population due to chance and not natural selection then genetic drift is occurring

Question 3

Example of genetic drift in plants
In a small population of five plants growing near a playground with a rubber floor; three of the plants have blue-and-white flowers and two of the plants have pink-and-white flowers

By chance, most of the seeds from the pink-and-white flowered plants end up on the rubber floor of the playground, whereas all the seeds from the blue-and-white flowered plants land on fresh fertile soil where they are able to germinate and grow

Over several generations, the allele for the pink-and-white flowers may disappear from this population due to chance (because the seeds carrying pink-and-white alleles for flower colour cannot germinate on rubber)