Conservation in Genetics 2. Flashcards
Why conserve genetic diversity
Biodiversity is the variety of life, including all genes, species and ecosystems, and the ecological processes of which they are part of.
Direct benefits of genetic diversity include
food, medicine, clothing, building supplies, shelter, 40% of perscription & non-perscription drugs have ingredients extracted from plants & animals
Indirect benefits of genetic diversity
Ecosystem services such as maintain water quality, buffer ecosystems against storms and drought, preserve soils preventing loss of nutrients, mitigate pollution, help the breakdown of organic wastes and cycling minerals.
Census population size (N)
Is the number of individuals in the population
Effective population size (Ne)
Is the actual number of individuals that successfully contribute to the next generation
Why is understanding genetic diversity important in conserving small and declining populations of endangered species.
- Reduction in reproductive fitness
- Adaptation and viability
- Re-introduction
- Taxonomic uncertainty
- Invasive Species
Examples of natural pressures to a population
Sudden climatic events or diseases
Examples of an anthropogenic pressure to a population
overharvesting or habitat degradation/loss
What is genetic drift
Drastic reduction in population size can lead o significant losses of genetic diversity.
In turn, small populations can lose genetic variability faster than large populations due to genetic drift.
Drift can override natural selection leading to:
Loss of adaptive potential.
Divergence of populations in fragmented habitat.
Fixation of deleterious alleles.
What is Population Bottleneck
Is a drastic reduction in effective population size leading to a significant loss of genetic variability.
Founder Event is…
A variant of bottleneck event except that it is directly related to a colonization event by a small number of individuals.
Causes of Genetic Bottleneck
Natural (unusual or catastrophic events such as floods, storms, ice melt/cover, disease outbreaks) or anthropogenic (habitat loss, overharvesting, competition with introduced non-native species,
Consequences of genetic bottleneck
Reduced gene pool, inbreeding, loss of adaptive potential, loss of competitive advantage BUT may
lead to some positive effects such as loss of rare deleterious alleles and positive selection (if bottleneck
event was selective and not random).
What is the Founder effect
Founder effects are known to drive the genetic structure of passively dispersed aquatic invertebrates (e.g. water fleas, Daphnia spp)
Evident in plant and animal populations that recolonize an area where life was wiped out e.g. Krakatoa volcano
Inbreeding is defined by
The mating among relatives.
Expected to happen small populations.
Inbreeding results in:
Increased homozygosity leading to inbreeding depression.
- reduced fecundity
- reduced size, growth, survival of offspring
- increased frequency of deformities
Non Indigenous Invasive Species (NIS) are…
organisms that have been introduced outside their natural distribution range by means of anthropogenic activities (e.g. transportation, food, tourism)
Invasive Alien Species (IAS)
are NIS that have an adverse effect on ecosystems and/or people.
What annual cost does invasive species have to irelands economy
A 2013 review estimated an annual cost of invasive
species to the Irish economy of €202,894,406; and to the UK economy of €2.3 billion
Among the most important impacts of the introduction and spread of invasive species are:
- Loss of (native) biodiversity
- Environmental degradation and ecosystem services
- Human health
- Financial costs
