The Ontological Status Of Species And New Biological Essentialism

Species is one of the most basic concepts for almost all branches of biology, and it is also one of the most controversial concepts. Although this concept is frequently used by philosophers and scientists, there is little consensus of the nature of species. What is the nature of species? It is usually called "the species problem". An important aspect of "the species problem" is about the question of what "the ontological status of species" is.Traditionally, the answer to the issue about "the ontological status of species" is biological essentialism. Biological essentialism claims that species is a "natural kind". It argues that all and only the members of a species have a common essence; each species is separated from all others by a sharp discontinuity; and each species is constant. Biological essentialism once prevaied for a long time in biology until the Darwin’s evolution is put forward. The Darwin’s gradualism argues that species are gradual, and the boundaries between species are vague. This view conflicts with biological essentialism. With the continuous transmission of Darwin’s ideas, the thought that species are gradual widely accepted by people, while biological essentialism gradually abandoned by philosophers and scientists. Today, that biological essentialism is incompatible with modern Darwinian theory has been a received view.In recent years, some philosophers try to resurrect biological essentialism by using the new biological resources. These philosophers put forward some different viewpoint. They offer some new forms of essentialism which depart from traditional biological essentialism, thus their theories are known as "new" biological essentialism. It mainly includes such theory:DNA barcode theory, historical essentialism, relational essentialism and hybrid biological essentialism, etc. These new theories roughly take three different approaches to resurrect biological essentialism. DNA barcode theory stand for the first approach, which try to take the genetic properties as the essence of species in order to replace the traditional morphological and physiological characteristics. The second approach is represented by historical essentialism and relational essentialism. It abandons the traditional view which take intrinsic properties as the essence of species, and try to replace the intrinsic properties with relational properties. Hybrid biological essentialism stands for the third approach. It mainly includes "Intrinsic Biological Essentialism" (INBE) and Homeostatic property cluster (HPC) theory. It can be regarded as a mixture of the first two approaches. All three approaches seemingly brought a lot of hopes for resurrecting biological essentialism, however there are so many defects in their own theories that they doesn’t really provide successful defense for biological essentialism.The failure of new biological essentialism dues to the conflict between new biological essentialism’s ontological presupposition and modern biology practice. The conflict leads to the tension between biology and essentialism in the deeper sense. By analyzing the origin of biological essentialism, I point out that the traditional biological essentialism may made the wrong understanding about the nature of species, and that the new biological essentialism lasted for such a mistake which gives rise to the tension mentioned above. The modern biological theory about the nature of species has confirmed our composition further. Modern biologists and essentialists hold the opposite view on the question of how to understand the nature of species. The former claims that species is an "individual", and that the members of an individual are heterogeneous, they must be appropriately causally connected; while the latter claims that species is a "kind", and that the members of a kind are homogeneous, they must have the appropriate similarities. I argue that the best way to eliminate the tension between biology and essentialism is to abandon the biological essentialism, and regard species an "individual" rather than a "kind"However, we regard species as an "individual", but this idea does not mean that species can’t be seen as a "kind". I think that these two ways of understanding species are not incompatible in a certain sense, and they can be integrated into the understanding of the species. As a result, we get the new understanding about the nature of species. That is, the species can be seen as "heterogeneous kinds". This concept allows us not only to regard the species as a "kind", but also as an "individual". This new understanding of the nature of species gives up the biological essentialism, and at the same time, it retains the value of epistemology of regarding the species as "natural kinds".