The Species Problem and Conservation: What are We Protecting?

Abstract

Although conservation biologists base most of their activities on species taxa, they have participated little in the debate of systematists and evolutionary biologists about the recognition and nature of species. It is clear from this debate that there is no agreement on what species are, how they should be delimited, or what they represent. But in conservation science, and particularly in the selection, design and management of protected areas, species are either treated as types or as evolutionary units. A typological view of species may lead to a failure to protect the real diversity of life in the long term, if conservation priorities are set on the basis of species numbers or on circumscriptions of endangered, threatened, or endemic species taxa that result from the use of different species concepts. Considering species as typological entities may also lead workers to disregard geographic variation and to neglect the problem of deciding which level of variability to protect. It may even affect the goal of maintaining the evolutionary potential of organisms, if the focus is placed on the preservation of a sample of the existing types in populations that will persist as little changed as possible. When species are considered as evolutionary units, attention is shifted from the level of species to that of populations and metapopulations. Problems may still arise if these populations are considered in the context of species taxa, particularly if their composition is managed or if indicator species are used. A closer interaction between systematists and conservation biologists is suggested. Although the pressures of time and the difficulties faced by conservation biologists cannot be denied, considering the species problem more critically may result in recognizing the limitations of the taxonomic information used; it may also contribute to the refinement of the concepts and methods involved in their activities, making them more congruent with the nature of biological diversity.

The reality of taxonomic change

“…We agree broadly with many of the points raised by Agapow and Sluys [1]. Indeed, their response seems to have been triggered by observations similar to those that motivated our own article [2]. However, we believe that parts of our paper have been misunderstood, and we welcome the opportunity for clarification.…”

“…In their recent TREE paper [1], Isaac et al assert that species numbers are increasing rapidly owing to 'taxonomic inflation', where previously identified species are reclassified under new species concepts into smaller and more numerous new taxa. Using recent phylogenetic concepts (as opposed to classic concepts, notably the biological or isolation concept) will certainly lead to an apparent increase in species number [2][3][4]. What is unsupported is that such inflation is the dominant force behind the current increase in species numbers.…”

“…As we acknowledged in our paper [2], the solutions that we offered to the problem of taxonomic inflation are flawed, and we did outline these shortcomings. No solution is infallible or easy: however, we should to try to avoid incorrect conclusions in comparative biology, ecology and conservation.…”

“…Species numbers are increasing in many groups [3], and measures of species richness become less compatible [2] as the PSC gains popularity.…”

<b>Genetic Conservation of Brazilian Fishes - Present State and Perspectives</b>

“…These data can contribute to the definition of priority regions for the establishment of areas of high diversity or of endemism, field management of endangered populations, and planning strategies of maintenance of captive breeding (Seal, 1988;OBrien & Mayr, 1991;Rojas, 1995). Moreover, data on species recovery priorities can be used for the identification and/or creation of distinct gene banks -in situ, ex situ and in vitro -as proposed by Toledo Filho et al (1992) (Table 3).…”