Conservation Genetics
The application of genetic and genomic principles to conserving biodiversity, with a focus on the genetic threats facing small and fragmented populations.
Definition
Conservation genetics is the use of genetic theory and techniques to reduce the risk of extinction and preserve biodiversity. It addresses how genetic diversity is generated, lost, and managed, and how genetic information guides decisions about populations, species, and their management.
Scope
This area covers the genetic dimension of conservation: the maintenance of genetic diversity, the genetic problems of small populations, the definition of management units, and genetic interventions such as translocation and rescue. It includes population genetics applied to wild populations and the use of molecular markers and genomics for conservation. It excludes the demographic and ecological aspects of small-population biology covered under extinction risk and the systematics of describing species.
Sub-topics
Core questions
- Why does genetic diversity matter for the survival of populations?
- What genetic problems threaten small and isolated populations?
- How are conservation units defined from genetic data?
- When and how should genetic interventions such as rescue be used?
Key concepts
- Genetic diversity and heterozygosity
- Effective population size
- Genetic drift
- Inbreeding and inbreeding depression
- Evolutionary potential
- Conservation units and genomics
Key theories
- Loss of genetic diversity in small populations
- Small populations lose genetic variation through genetic drift and inbreeding faster than mutation can replenish it, reducing adaptive potential and fitness — a central concern of conservation genetics.
- Effective population size
- The genetically effective population size, usually far below the census size, governs rates of drift and inbreeding and is a key quantity for predicting genetic erosion and setting management targets.
- Genetic rescue
- Introducing individuals from other populations can restore genetic variation and reverse inbreeding depression, improving fitness in small, isolated populations when applied with attention to outbreeding risk.
Clinical relevance
Conservation genetics informs decisions on captive breeding, reintroduction, translocation, and the prioritization of populations for protection. Pedigree management in captive programmes, the diagnosis of inbreeding problems in endangered species such as the Florida panther, and the delineation of units for legal protection all rest directly on its principles.
History
The field was launched by Otto Frankel and Michael Soule's recognition in the 1970s-1980s that genetic factors affect extinction risk, formalized in the 'small-population paradigm'. Molecular markers expanded its reach through the 1990s, and high-throughput genomics since the 2000s has transformed how genetic diversity and adaptation are measured in wild populations.
Debates
- How important are genetic versus demographic threats?
- Conservation biologists have debated whether small populations typically go extinct from demographic and environmental causes before genetic problems matter; mounting evidence of inbreeding depression and successful genetic rescue has shifted views toward taking genetic threats seriously.
Key figures
- Richard Frankham
- Fred Allendorf
- Otto Frankel
Related topics
Seminal works
- frankham2010
- allendorf2013
- whiteley2015
Frequently asked questions
- Why does genetic diversity matter for conservation?
- Genetic diversity is the raw material for adaptation. Populations with little variation are less able to respond to disease, climate change, and other pressures, and they tend to suffer reduced fitness from inbreeding, raising their extinction risk.
- What is effective population size?
- A measure of how a population behaves genetically — specifically how fast it loses diversity through drift and inbreeding. It is usually much smaller than the actual number of individuals, so even seemingly large populations can be genetically vulnerable.