The Selfless Geneticist


Conservation and the Genetics of Populations . Allendorf, F. W., and G.Luikart . 2006 . Blackwell Publishing , Malden , Massachusetts . 661 ( xix + 642 ) pp . $69.95 ( paperback ). ISBN 1-4051-2145-9 .

The Florida panther was once considered one of 15 subspecies of puma (Felis concolor) in North America. By the 1980s, the last remaining population of the panther was down to just a few individuals that faced a degraded habitat and severely reduced genetic diversity. Managers of the recovery effort had to decide between preserving the Florida panther as a unique taxon and restoring diversity to the embattled population. A genetic analysis showed that subspecies status was unlikely for the large cat, and managers chose a genetic rescue, releasing eight Texas cougars in southern Florida in the 1990s. With the introduction of new genes, the panther rebounded—the population now numbers close to a hundred, and there are fewer indications of inbreeding. The species may now be poised to expand its range beyond the narrow, swampy confines of southern Florida.

In a time of increasing habitat fragmentation and rapid climate change, it is likely that such translocations and the management of gene flow will require the expertise of evolutionary biologists and conservation geneticists. Wildlife managers will need to understand genetic variation and the effects of inbreeding and outbreeding, if not be comfortable wielding pipettes or running agarose gels. In their wide-ranging book, Allendorf and Luikart set out to train undergraduates and beginning graduate students in the basics of conservation genetics.

As any student of the discipline knows, it is a long journey. Much of the book is introduction, reviewing the basics of genetic variation and evolutionary change. It does not really get underway until Part III on page 305, which includes an excellent chapter on conservation breeding and restoration. The chapter on invasive species is informative—I had never heard of an eradication unit, the evil twin of the evolutionary significant unit or ESU. The last chapter on forensic and management implications provides some nice case studies of the use of DNA in wildlife identification. The appendix on statistical methods, which I intended to skip or at best skim, is surprisingly lucid and would be helpful to any advanced undergrad or graduate student early in his or her career.

After the development of PCR, with the rapid rise in population genetic studies, geneticists were sometimes maligned for not knowing their species well enough to understand them in the field. Yet DNA technology has done a lot for conservation. In the 19th century, scientific collectors competed with commercial and sport hunters for specimens, helping drive some species to the edge of extinction. Since the molecular revolution, lethal sampling is often unnecessary, allowing the study of systematics and conservation to become more closely aligned. Entire studies can now be based on the flecks of skin sloughed from a whale, the blood from a turtle's tail, or the soon-to-be regenerated leg from a crab. It is no longer necessary to kill a cetacean to understand its life history or capture a carnivore to follow its movements or learn about its diet. DNA from fecal and hair samples make noninvasive studies practical and profoundly informative. Which is not to say they are easy. Allendorf and Luikart's book can help wildlife managers, faced with terms such as haplotype diversity and F statistics make sense of the information.

How does it compare with some of my favorite introductory texts, Hartl and Clark's (1989) Principles of Population Genetics (Sinauer Associates, Sunderland, Massachusetts); Graur and Li's (2000) Fundamentals of Molecular Evolution (Sinauer); Groom, Meffe, and Carroll's (2006) Principles of Conservation Biology (Sinauer)? It stands up quite well and is an excellent complement to Frankham, Ballous, and Briscoe's (2002) Introduction to Conservation Genetics (Cambridge University Press, Cambridge, United Kingdom), which may be more accessible to the nonspecialist. Nevertheless, the volume would have benefited from proper proofreading. (As much as I like the idea of a study of muskrats in Backwater National Wildlife Refuge, it is really Blackwater.) Conservation and the Genetics of Populations is a magnanimous book, captured in the Zen vow that opens the preface: “The many beings are numberless; I vow to save them all.” Molecular assays alone will not do that, but in synthesis with ecology, evolution, and systematics, they provide some of the best tools we have.