Inbreeding depression effects on extinction time in a predator—prey system
Tóm tắt
Traditional methods of assessing population viability ignore both genetic—demographic interactions as well as community level dynamics. We address these deficiencies by presenting a model that investigates the effects of predation on a prey population experiencing inbreeding depression. Beginning with a simple Lotka—Volterra predator—prey system, we rewrite prey per capita mortality as a function of inbreeding. Inbreeding varies as a function of population size. Using computer simulation, we find that prey extinction times are inversely related to the level of inbreeding depression with and without predation. For all but very low levels of inbreeding depression, predation appreciably reduces persistence time. At moderate levels of inbreeding, predators go extinct before prey. When migration is introduced at low and moderate rates, persistence times only improve for those populations with low inbreeding depression measures. At a higher migration rate, persistence times are lengthened for low and moderately depressed prey populations. Increasing birth rates produce a visible, though noisy, trend towards increased times to extinction for low to moderate levels of inbreeding.
Tài liệu tham khảo
Allendorf, F.W. (1983) Isolation, gene flow, and genetic differentiation among populations. InGenetics and conservation: a reference for managing wild animal and plant populations (C.M. Schonewald-Cox, S.M. Chambers, B. MacBryde and W.L. Thomas, eds), pp. 51–65. Benjamin Cummings Publishing, Menlo Park, CA.
Belovsky, G.E. (1987) Extinction models and mammalian persistence. InViable populations for conservation (M.E. Soule, ed.), pp. 35–57. Cambridge University Press, New York, NY.
Brown, J.H. and Kodric-Brown, A. (1977) Turnover rates in insular biogeography: effect of immigration on extinction.Ecology 58, 445–9.
Charlesworth, D. and Charlesworth, B. (1987) Inbreeding depression and its evolutionary consequences.Ann. Rev. Ecol. System. 18, 237–68.
Charlesworth, D., Morgan, M.T. and Charlesworth, B. (1993) Mutation accumulation in finite populations.J. Hered. 84, 321–5.
Crow, J. and Kimura. M. (1970)An Introduction to Population Genetics Theory. Harper and Row, New York, NY.
Falconer, D.S. (1989)Introduction to Quantitative Genetics. Longman, New York, NY.
Frankel, O.H. and Soule, M.E. (1981)Conservation and Evolution. Cambridge University Press, Cambridge, UK.
Franklin, I.R. (1980) Evolutionary changes in small populations. InConservation biology — an evolutionary ecological perspective (M.E. Soule and B.A. Wilcox, eds), pp. 135–49. Sinauer, Sunderland, MA.
Futuyma, D.J. and Slatkin, M. (1983)Coevolution. Sinauer, Sunderland, MA.
Gilpin, M.E. and Soule, M. E. (1986) Minimum viable populations: processes of species extinction. InConservation biology: the science of scarcity and diversity (M.E. Soule, ed.), pp. 19–34. Sinauer, Sunderland, MA.
Goodman, D. (1987a) How do any species persist? Lessons for conservation biology.Cons. Biol. 1, 59–62.
Goodman, D. (1987b) The demography of chance extinction. InViable populations for conservation (M. E. Soule, ed.), pp. 11–34. Cambridge University Press, New York, NY.
Hartl, D.L. (1988)A Primer of Population Genetics. Sinauer, Sunderland, MA.
Hedrick, P.W. (1985)Genetics of Populations. Jones and Bartlett, Boston, MA.
Hedrick, P.W. and Miller, P.S. (1992) Conservation genetics: techniques and fundamentals.Ecol. Appl. 2, 30–46.
Lacy, R.C. (1987) Loss of genetic diversity from managed populations: interacting effects of drift, mutation, immigration, selection, and population subdivision.Cons. Biol. 1, 143–58.
Lande, R. (1988) Genetics and demography in biological conservation.Science 241, 1455–60.
Lande, R. and Barrowclough, G.F. (1987) Effective population size, genetic variation, and their use in population management. InViable populations for conservation (M.E. Soule, ed.), pp. 87–123. Cambridge University Press, New York, NY.
Lotka, A. (1925)Elements of Physical Biology. Williams and Wilkins, Baltimore, MD.
Morton, N.E., Crow, J.F. and Muller, H.J. (1955) An estimate of the mutational damage in man from data on consanguineous marriages.Proc. Natl. Acad. Sci., USA,42, 855–63.
Nei, M., Maruyama, T. and Chakroborty, R. (1975) The bottleneck effect and genetic variability in populations.Evolution 29, 1–10.
O'Brien, S.J. and Evermann, J.F. (1988) Interactive influence of infectious disease and genetic diversity in natural populations.Trends Ecol. Evol. 3, 254–9.
Pielou, E.C. (1977)Mathematical Ecology. John Wiley and Sons, New York, NY.
Pimm, S.L. (1991)The Balance of Nature? Ecological Issues in the Conservation of Species and Communities. University of Chicago Press, Chicago, IL.
Pimm, S.L., Gittleman, J.L., McCracken, G.F. and Gilpin, M. (1989) Plausible alternatives to bottlenecks to explain reduced genetic diversity.Trends Ecol. Evol. 4, 176–8.
Press, W.H., Teukolsky, S.A., Vetterling, W.T. and Flannery, B. P. (1992)Numerical Recipes in C: The Art of Scientific Computing (2nd edn). Cambridge University Press, Cambridge, UK.
Ralls, K., Ballou, J. and Templeton, A. (1988) Estimates of lethal equivalents and the cost of inbreeding in mammals.Cons. Biol. 2, 186–93.
Saloniemi, I. (1993) A coevolutionary predator—prey model with quantitative characters.Am. Nat. 141, 880–96.
Schonewald-Cox, C.M., Chambers, S.M., MacBryde, B. and Thomas, W.L. (eds) (1983)Genetics and Conservation: A Reference for Managing Wild Animal and Plant Populations. Benjamin Cummings Publishing, Menlo Park, CA.
Sih, A. (1987) Predators and prey lifestyles: an evolutionary and ecological overview. InPredation: direct and indirect impacts on aquatic communities (W. C. Kerfoot and A. Sih, eds), pp. 203–24. University Press of New England, Hanover, NH.
Slatkin, M. (1981) Fixation probabilities and fixation times in a subdivided population.Evolution 35, 477–88.
Soule, M.E., (ed.) (1986)Conservation Biology: The Science of Scarcity and Diversity. Sinauer, Sunderland, MA.
Taper, M.L. and Case, T.J. (1985) Quantitative genetic models for the coevolution of character displacement.Ecology,66, 355–71.
Vermeij, G.J. (1987)Evolution and Escalation. Princeton University Press, Princeton, NJ.
Volterra, V. (1926) Variations and fluctuations of the numbers of individuals in animal species living together. Reprinted (1931) inAnimal ecology (R. Chapman, ed.). McGraw-Hill, New York, NY.