Selection pressures produce a gradual change in allele frequencies over several generations
state what genetic drift is
A gradual change in allele frequencies in a small population due to chance and not natural selection.
state what the bottleneck effect
reduction in the gene pool of a population due to a dramatic decrease in population size.
state what the founder effect is
changes in allele frequencies occur in a different direction for the newly isolated small population in comparison to the larger parent population due to chance.
Define species diversity
Refers to the number of different species and the number of individuals within any one community
genetic diversity
the variety of genes possessed by the individuals that make up a population of a species
ecosystem diversity
the range of different habitats from a small local habitat to the whole of the earth
species richness
the number of different species in a particular area at a given time
Index of diversity
d = N(N-1) /Σn(n-1)
n = total no. of organisms for a single species in the community
N = total no. of organisms in the community
Σ = sum of
The larger the numberobtained, the higher the level of diversity
