What is Conservation Genetics? -- Application of genetics to preserve species as dynamic entities capable of coping with environmental change and encompasses: genetic management of small populations resolution of taxonomic uncertainties defining management units within species use of molecular genetic techniques in forensics & understanding species biology.

When a population or species disappears, all the genetic information carried by that population or species is lost! When a contiguous population is fragmented into many small populations, genetic diversity within each may decay over time “Gene pools are becoming diminished and fragmented into gene puddles” (Thomas Foose, 1983)

Why Genetics? Evolution is the single most unifying organizational concept in all of biology and should play a prominent role in conservation as well. Evolution is dynamic and change is expected. ecological systems are dynamic and generally not in equilibrium. The best way to manage such dynamic systems is a Conservationist rather than Preservationist approach.

Three biological reasons to believe genetics can make important contribution to conservation biology. Fundamental theorem of natural selection tells us that the rate of evolutionary change in a population is proportional to the amount of genetic diversity available.

Darwin-Wallace Theory of Natural Selection If supplied with sufficient nutrients and protection the total population size will increase geometrically. However, due to high death rates, geometric increase is not maintained indefinitely. All species are variable

Darwin-Wallace Theory of Natural Selection Those individuals with variations of characters that better enable them to survive and reproduce will leave proportionally more offspring. This results in the increase of the advantageous characters in the next generation.

There is a consensus among population geneticists that heterozygosity, or high genetic variation within individuals or populations, is positively related to fitness. The global pool of genetic diversity represents all the information for all biological processes on the planet. Loss of such diversity will probably decrease the ability of organisms to respond to environmental changes and discard information potentially useful to humans.

Basic problem linking genetics to conservation is that small populations, whether in the wild or captivity, tend to lose genetic variation over time. This loss of variation may well increase the probability of population extinction or reduced opportunities for future adaptation through evolutionary change.

The basic thrust of conservation genetics and the message to take from this course is: We must maintain natural patterns of genetic diversity at many levels and thus preserve options for future evolution!!!

Limitations of Genetics in Conservation Biology: Application of genetics to conservation problems is a young science that is still developing. Many genetic techniques are not cheap and can be misused or misapplied. Plant and animal tissues must be obtained and properly handled.

“Genetic factors do not figure among the four major causes of extinction (the Evil Quartet): overkill, habitat destruction and fragmentation, impact of introduced species, and secondary cascade effects”. Thus, although genetic factors are major determinants of a populations long-term viability, conservationists can do more for a threatened population in the short-term by managing its ecology.

Conservation Genetics deals with the genetic factors that affect extinction risk and genetic management regimes required to minimize 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 & ability to evolve in response to environmental change. Fragmentation of populations and reduced gene flow. Random processes (genetic drift) overriding natural selection as the main evolutionary force. Accumulation and loss (purging) of deleterious mutations.

Genetic adaptation to captivity & 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

Deleterious effects of fitness that sometimes occur as a result of outcrossing (outbreeding depression).

How is genetics used to minimize extinction? Reducing extinction risk by minimizing inbreeding and loss of genetic diversity. Identifying populations of concern. Resolving population structure Resolving taxonomic uncertainties Defining management units within species.

Detecting hybridization Non-intrusive sampling for genetic analyses. Defining sites for reintroduction. Choosing the best populations for reintroduction. Forensics. Understanding species biology

Biodiversity -- the variety of ecosystems, species, populations within species and genetic diversity within species. Biological diversity of planet is being rapidly Depleted due to direct and indirect consequences Of humans. Scale of this problem is enormous and has been Termed the “Sixth Extinction” as its magnitude Is comparable with that of the other five mass Extinctions revealed in the geologic record.

Conservation genetics is motivated by the need to reduce current rates of extinction and to preserve biodiversity

Why Conserve Biodiversity? Because humans Derive many direct and indirect benefits from The living world, we have a stake in conserving Biodiversity for: resources we use ecosystem services it provides pleasure we derive from living organisms ethical reasons

Bioresources includes all food, many pharmaceuticals, clothing fibers, rubber & timber with a value in billions of dollars annually. About 25% of all pharmaceutical prescriptions in the US contain active ingredients derived from plants. The natural world contains many potentially useful novel resources: Ants contain novel antibiotics that are being investigated for use in human Medicine.

Ecosystem Services -- essential biological functions That are provided free of charge by living organisms And which benefit mankind such as: Oxygen production by plants Climate control by forests Nutrient cycling Natural pest control Pollination of crop plants These services have been valued at $33 trillion/year or almost double the $18 trillion yearly global national product!!!!

Aesthetics -- Humans derive pleasure from living organisms. This translates into direct economic value. Koalas are estimated to contribute $70 million annually to the Australian tourism industry.

Ethics -- The ethical justifications for conserving biodiversity are simply that one species does not have the right to drive other species to extinction!

The IUCN (the World Conservation Union) Recognizes the need for conservation at the Levels of: genetic diversity species diversity ecosystem diversity

Based on the principles of population biology, in 1996 the IUCN defined criteria to classify species into: Critically Endangered Endangered Vulnerable Lower Risk This classification is used as the basis of listing species in the IUCN Red Books of endangered animals. Look at Table 1.2; pg 5

It is of critical importance to define endangerment as it is the basis for legal protection for species. Most countries have Endangered Species Acts that provide legal protection for threatened species and usually require the formulation of recovery plans. Additionally, trade in threatened species is banned by countries that have signed the Convention on International Trade in Enangered Species (CITES).

Small populations suffer from inbreeding & loss of genetic diversity resulting in elevated extinction risks. Consequently, a major objective of genetic management is to minimize inbreeding & loss of genetic diversity.