Wow 8O I just read an awsome article by J.E.N. Vernon on his theory of Reticulate Evolution. Amazing new ideas on coral evolution. Here's a summery quote of Vernon's article (sorry for any typos, but I did this by hand when my fingers were numb):
"Species have long been regarded as the fundamental units or 'building blocks' of of nature, units that can be named, discribed and studied (Mayr 1942). They have thus been contrasted with other taxonomic levels that are supposedly human-created and therefore matters of taxonomic opinion. When this concept of species is applied to corals over very large peographic ranges, it breaks down. In reality, most species are only clearly defined units in limited geographic space (Vernon 1995). When that space is progressively increased (as inviewing a particular species in one country then in many countries), it becomes progressively not that species. The fundamental reason for this is that coral species exist in geographic space as reticulate, or interlinked patterns that change continuously, not as geogrphically uniform units. This creates a dilemma, as humans cannot easily communicate in terms of continua: They need dicrete units of some form or another.
When this issue is considered in evolutionary time, not just in geographic space, the issues that arise make it nessary to consider evolutionary change in a way that id different from that which has become generally accepted in both the popular and scientific literature. Reticulate evolution represents a paradigm that cannot be mapped direcly onto traditional views of species, yet is ighly explanitory of a wide array of paleontological, taxonomic, systematic and biogeographic issues that have been debated throughout much of the 20th century."
The whole article is long and has some really cool pictures graphing his ideas. It appears in the December/January issue of Coral magazine.
"Species have long been regarded as the fundamental units or 'building blocks' of of nature, units that can be named, discribed and studied (Mayr 1942). They have thus been contrasted with other taxonomic levels that are supposedly human-created and therefore matters of taxonomic opinion. When this concept of species is applied to corals over very large peographic ranges, it breaks down. In reality, most species are only clearly defined units in limited geographic space (Vernon 1995). When that space is progressively increased (as inviewing a particular species in one country then in many countries), it becomes progressively not that species. The fundamental reason for this is that coral species exist in geographic space as reticulate, or interlinked patterns that change continuously, not as geogrphically uniform units. This creates a dilemma, as humans cannot easily communicate in terms of continua: They need dicrete units of some form or another.
When this issue is considered in evolutionary time, not just in geographic space, the issues that arise make it nessary to consider evolutionary change in a way that id different from that which has become generally accepted in both the popular and scientific literature. Reticulate evolution represents a paradigm that cannot be mapped direcly onto traditional views of species, yet is ighly explanitory of a wide array of paleontological, taxonomic, systematic and biogeographic issues that have been debated throughout much of the 20th century."
The whole article is long and has some really cool pictures graphing his ideas. It appears in the December/January issue of Coral magazine.
