The Species in Conservation

Taxonomy- the science of classification

Why define species? Species are the focus of legislation:  Endangered Species Act (ESA)  Convention on International Trade in Endangered Species (CITES)

Species Concepts Are Vague a species is difficult to define biologically The biological world is a continuum of organization…What exactly is an individual?

Typological -vs- Populational Perspectives Typological- categorical entities; morphologically distinct; immutable creations Populational- focuses on variation within species as a basis of evolutionary change

Biological Species Concept groups of actually or potentially interbreeding populations that are reproductively isolated from other such populations

Phylogenetic Species Concept based on shared derived characters (synapomorphies) Cladistics- phylogenetic systematics would result in the recognition of more species than at present and perhaps greater recognition of populational diversity.

Evolutionary Species Concept a single lineage of ancestral descendant populations of organisms that maintain an identity distinct from other such lineages

Ecological Species Concept …a lineage that occupies an adaptive zone different from that of other lineages.

Implications of Species Concepts on Conservation  The critical evolutionary and ecologically functional unit is the population.  Semi-isolated populations may play different functional roles in different systems.  A species level focus does not address habitat and ecosystem loss.

Wilson, E.O The diversity of life. Harvard University Press. A species is a population whose members are able to interbreed freely under natural conditions. Subspecies are individuals occupying a particular part of the species range, with genes and natural history distinct from those of other subspecies