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Richard Frankham
ment of such populations; this can only be resolved by clearly defining the
procedures and testing them against alternative management programs.
Research Using Other Species
Butterflies (Brakefield and Saccheri 1994), Flour Beetles (Pray et al. 1994),
House Flies (Backus et al. 1995), fish (Leberg 1992), and native mice (Brewer et
al. 1990) have begun to be used as laboratory species to model problems in
conservation genetics. Lacy and colleagues have used native species of mice in
work that bridges the gap between laboratory species and wildlife (Brewer et al.
1990; Jimenez et al. 1994). Vrijenhoek and colleagues (see Vrijenhoek 1994) have
made innovative use of a combination of field and laboratory studies in two
species of desert fish, one of which was endangered.
Other Questions That Need Addressing in
Laboratory Species
1. What are the minimum viable population sizes required to avoid inbreeding
depression and to avoid loss of evolutionary potential? Franklin (1980) predicted that N e ’s of 50 and 500, respectively, were needed. We are currently
evaluating these issues.
2. How can genetic adaptation to captivity be minimized and reintroduction
success maximized? Equalizing family sizes, extending the generation interval, and minimizing selection in captivity are predicted to minimize genetic
adaptation to captivity and hence maximize reintroduction success (Frankham and Loebel 1992; Frankham 1995d). The predicted benefits of equalizing family size in reducing the rate of genetic adaptation to captivity has
recently been verified (Frankham and Margan, unpublished data).
3. Is minimizing kinship the optimum procedure for managing small pedigreed
populations of endangered species? Several procedures have been, or still are,
recommended for the genetic management of such populations. Ballou and
Lacy (1995) predicted that minimum kinship is the optimum procedure to
retain genetic diversity and allelic diversity, based on computer simulations.
However, it was not necessarily this procedure that minimized inbreeding.
This procedure requires urgent testing as it is currently being applied to
endangered species. It has recently been evaluated in Drosophila (Montgomery et al. 1997).
4. What determines the evolutionary potential of populations—heterozygosity
or allelic diversity? Most considerations are based on heterozygosity, but
Allendorf (1986), Fuerst and Maruyama (1986), and others have raised the
question of whether allelic diversity is the critical issue. This issue can only
be resolved experimentally.
5. What is the optimum genetic management strategy for populations of endangered species founded from few individuals? This issue is a matter of great
Richard Frankham
ment of such populations; this can only be resolved by clearly defining the
procedures and testing them against alternative management programs.
Research Using Other Species
Butterflies (Brakefield and Saccheri 1994), Flour Beetles (Pray et al. 1994),
House Flies (Backus et al. 1995), fish (Leberg 1992), and native mice (Brewer et
al. 1990) have begun to be used as laboratory species to model problems in
conservation genetics. Lacy and colleagues have used native species of mice in
work that bridges the gap between laboratory species and wildlife (Brewer et al.
1990; Jimenez et al. 1994). Vrijenhoek and colleagues (see Vrijenhoek 1994) have
made innovative use of a combination of field and laboratory studies in two
species of desert fish, one of which was endangered.
Other Questions That Need Addressing in
Laboratory Species
1. What are the minimum viable population sizes required to avoid inbreeding
depression and to avoid loss of evolutionary potential? Franklin (1980) predicted that N e ’s of 50 and 500, respectively, were needed. We are currently
evaluating these issues.
2. How can genetic adaptation to captivity be minimized and reintroduction
success maximized? Equalizing family sizes, extending the generation interval, and minimizing selection in captivity are predicted to minimize genetic
adaptation to captivity and hence maximize reintroduction success (Frankham and Loebel 1992; Frankham 1995d). The predicted benefits of equalizing family size in reducing the rate of genetic adaptation to captivity has
recently been verified (Frankham and Margan, unpublished data).
3. Is minimizing kinship the optimum procedure for managing small pedigreed
populations of endangered species? Several procedures have been, or still are,
recommended for the genetic management of such populations. Ballou and
Lacy (1995) predicted that minimum kinship is the optimum procedure to
retain genetic diversity and allelic diversity, based on computer simulations.
However, it was not necessarily this procedure that minimized inbreeding.
This procedure requires urgent testing as it is currently being applied to
endangered species. It has recently been evaluated in Drosophila (Montgomery et al. 1997).
4. What determines the evolutionary potential of populations—heterozygosity
or allelic diversity? Most considerations are based on heterozygosity, but
Allendorf (1986), Fuerst and Maruyama (1986), and others have raised the
question of whether allelic diversity is the critical issue. This issue can only
be resolved experimentally.
5. What is the optimum genetic management strategy for populations of endangered species founded from few individuals? This issue is a matter of great