Notes
1. Ex situ breeding refers to breeding of species outside their natural habitat. The location can be a zoo but also a (semi)-reserve.
2. The terms conservation and preservation are often used interchangeably to describe human activities in preventing species extinction. Frankel and Soulé [1981] consider conservation as "policies and programmes for long-term retention of natural communities which provide the potential for continuing evolution". Preservation refers, according their opinion, to "maintenance of individuals or groups but not for their evolutionary change".
3. The abbreviation IUCN refers to International Union of Conservation of Nature and Natural Resources, the former name of the World Conservation Union.
4. Schaffer[1987] prefers to use the term "uncertainty" rather than the term "stochastic process" in the context of population dynamics. He argues that there is little practical difference between a purely random event and the results of processes which, because they are not understood, remain unpredictable.
5. SSC = Species Survival Commission of the World Conservation Union. The CBSG was previously named Caption Breeding Specialist Group.
6. Gregor Mendel published the results of his study on inheritance in 1866. However, this work remained unknown until 1900 when Hugo de Vries published the results of his study and referred in a footnote to Mendel's work. See Chapter 17. Flowering of Mendelian Genetics in Mayr [1982].
7. A negative value for lethal equivalents implies that inbred offspring have a higher survival chance than non-inbred offspring.
8. Population sizes as mentioned in the (new) Red List categories [IUCN, 1994a] are based on categories of effective populations sizes and a Ne/N ratio of 0.2 as defined in the original Mace-Lande criteria [Mace and Lande, 1991].
9. The '90 percent level' as recommended by Soulé et al. [1986] refers to ideal populations. It is based on observations that inbreeding coefficients lower than 0.1 do, in general, not affect the viability of a population [Ballou, pers. comm]. Soulé et al. [1986] assume that new technologies for maintaining species will have been developed in 200 years time and replace captive breeding.
10. The map distance z is the average number of recombination events involving a given chromatid.
11. Note that ChromoFlow expresses mean values in terms of proportion of the original genetic variation.
12. Genetic variation in current populations of endangered species may not reflect, due to recent bottlenecks, the original genetic variation.
13. It is likely that genetic studies on highly endangered species involve specimens in ex situ populations. Such specimens may not reflect a random sample from a source population. For example, founders of zoo populations that have been established in the past (i.e. before genetic management was considered important) may originate from the same litter or nest. This requires information on capture techniques as have been applied in the past.
14. The generation of an individual is determined by the parent belonging to the latest generation e.g. the mating of F1 and F2 individuals result in F3 offspring. Individuals which both parents are wild-born are defined as the F1 generation [Princée, 1988]. Note that CITES uses a definition of captive-born generation which is based on the youngest generation e.g. wild x F10 produces F1 offspring.