Biodiversity at several levels

Genetic Diversity
All species consist of individuals that vary genetically from one another to some degree
Encompasses the varieties in DNA among individuals within species and populations
The raw material for adaptation to local conditions

Populations with low genetic diversity are vulnerable
Inbreeding depression = genetically similar parents mate and produce inferior offspring
Genetic bottleneck = limited variety of genetic material is available to be passed along by the small number of surviving individuals to their descendants