Download Genetic Drift - San Elijo Elementary School

Genetic Drift
Objective 5
Genetic Drift
Natural Selection is not the only source of
evolutionary change
 In smaller populations traits can change
simply by random chance
 The random changing of alleles in smaller
populations is called genetic drift

Genetic Drift Example

A small
population
of lizards
live on the
edge of a
desert
Genetic Drift Example
They live
very far
apart from
each other
 Only two
of them
will mate

Genetic Drift Example

The color
of the next
generation
is random
(based on
which 2
lizards
mate)
The Founder Effect

When a small population of animals enters
a new habitat there is a burst of genetic
drift