One of the greatest challenges currently facing wild animal and plant populations is tackled in a new book.
The natural world now exits mostly in pieces, with human activity over the last 500 years profoundly reducing and fragmenting natural habitats. Wild plant and animal populations surviving in these habitat fragments are typically small and isolated. These populations are likely to be suffering from the loss of genetic diversity leading to a limited ability to evolve, as well as reduced fitness, as a consequence of inbreeding, making them more prone to extinction. That’s the bad news.
The good news is that these negative effects can often be reversed by re-establishing gene flow between isolated populations, a process termed genetic rescue. But genetic rescue is currently very rarely undertaken. As a consequence, many small isolated populations will unnecessarily go extinct for genetic reasons. We estimate that currently there are well over a million small isolated populations of threatened species are in need of genetic rescue. This is one of the greatest unmet challenges currently facing conservation biology.
High resolution genetic techniques are often used to detect differentiation among isolated populations, with many studies then concluding that genetically differentiated populations should be managed separately. However, in many cases this differentiation may be the recent product of population fragmentation and not natural. We are hoping to see a paradigm shift in wildlife management where the detection of genetic differentiation will prompt the question of whether genetic rescue is needed, rather than simply opting for separate management and often increased population extinction.
Although rapidly advancing genetic and genomic technologies are continually providing new tools to measure population differentiation and its consequences, adequate guidance on using these data for effective conservation has been lacking. This book is aimed at bridging the gap between conservation and evolutionary genetics theory, molecular data analysis and wildlife management practice. It provides a thorough exploration of the genetic issues faced by fragmented populations, the reasons why the use of genetic rescue has been limited to date and the theory and practicalities of re-establishing gene flow.
The book, over 5 years in the writing, represents an international collaboration by a team of scientists from Australia and the USA. It compromises 15 chapters and over 400 pages with examples and case studies from around the world.
Dr Mark Eldridge, Principal Research Scientist, Terrestrial Vertebrates, Australian Museum Research Institute
Emeritus Professor Dick Frankham, Research Associate, Australian Museum Research Institute; School of Biological Science, Macquarie University
- Frankham, R., Ballou, J.D., Ralls, K., Eldridge, M.D.B., Dudash, M.R., Fenster, C.B., Lacy, R.C., and Sunnucks, P. 2017. Genetic management of fragmented animal and plant populations. Oxford University Press: Oxford, UK.
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