Conservation genetics deals with the genetic factors that affect extinction
risk and genetic management regimes required to minimise these
risks. There are 11 major genetic issues in conservation biology:
• The deleterious effects of inbreeding on reproduction and survival
(inbreeding depression)
• Loss of genetic diversity and ability to evolve in response to environmental
change
• Fragmentation of populations and reduction in gene flow
• Random processes (genetic drift) overriding natural selection as the
main evolutionary process
• Accumulation and loss (purging) of deleterious mutations
• Genetic adaptation to captivity and its adverse effects on reintroduction
success
• Resolving taxonomic uncertainties
• Defining management units within species
• Use of molecular genetic analyses in forensics
• Use of molecular genetic analyses to understand aspects of species
biology important to conservation
• Deleterious effects on fitness that sometimes occur as a result of outcrossing
(outbreeding depression).
The effects of small population size are of major concern in conservation
biology, since endangered species have small and/or declining populations.
Small populations suffer from inbreeding and loss of genetic
diversity resulting in elevated extinction risks. Consequently, a major
objective of genetic management is to minimize inbreeding and loss of
genetic diversity.
This textbook is concerned with the 11 issues listed above.
The structure and content of conservation genetics is illustrated in
Fig. 1.5. Conservation genetics is an applied discipline that draws
heavily upon evolutionary, population and quantitative genetics and
taxonomy.