Dinosaur Evolution

Evolutionary Concepts Defining Speciation:

BSC and Recognition concept

Species are produced by individual speciation events, so a single species concept can’t be defining all species. Hugh Paterson’s ideas are significant in understanding evolution. Paterson argues that speciation is not an adaptive process, but is a result of the adaptation of intricate bonding mechanisms to a new environment (Paterson). The conceptual basis of his research is the Recognition Concept of Species. He argues that the Biological species concept isn’t the only mode of speciation, and that this is a better way to define certain species. The biological species concept defines a species as a reproductive group; so there are many limitations. The main limitation is with fossils because fossilized species can’t be applied to the BSC because the organisms no longer mate so their mating pattern in unknown. Paterson believes that species combine as a result of pre-zygotic (before zygote forms) factors within species and not because of isolation mechanisms between species as the biological species concept supports (Paterson). He developed the Recognition concept of species which is compatible with allopatric speciation.

The Biological species concept (BSC) has become the main concept defining species, founded by Ernst Mayr in 1942. It defines what occurs in nature. There are a few limitations to this concept. It can not be applied to asexually reproducing organisms so extinct species that we only know about through fossils can’t be applied to this concept because the sexual stage is not determinable. There is also no logical way to apply the standards of reproductive isolation to most situations. The biological species concept explains why members of the same species resemble one another and differ from other species by phenotype (Ridley, Mark). When two organisms within a species go through sexual reproduction, a combination of the parents genes are passed to the offspring which shuffles the gene pool of that species, therefore isolating the species by its gene pool; the genes are not transferred to another species gene pool. Under this concept, individual forms of the same "kind" of animal are usually regarded as one species, because the geographic forms interbreed, or might if they were in the same area and in contact with each other. This is a problem because if geographically-isolated organisms seldom show their willingness to interbreed. According to the BSC, if different organisms are just somewhat different , they would probably interbreed if given the chance, therefore they should be grouped in the same species. However, different parts of the BSC also say that because two organisms rarely interbreed with possible hybrids, doesn’t necessarily mean that they are part of the same species.

The Recognition concept was brought up by Hugh Paterson, a critic of the biological species concept. He wanted to explore another kind of concept that didn’t have as many limitations