Genetics of Speciation

this type of speciation does not happen very often. Hybridization without polyploidy is more uncommon than that which happens with polyploidy.

No one knows exactly how fast speciation occurs over time. Some believe there is phyletic gradualism, which means there is a slow but gradual change in species. Punctuated evolution involves more rapid evolution, which is seen with domestication and plant manipulation by growers. Corn, for example, has rapidly evolved over a short period of time. This leads some to wonder why actual natural evolution takes so long. The fossil record supports punctuated evolution, with the sudden appearance of certain organisms occurring in the fossils seen by paleontologists.

GENETICS OF SPECIATION

Charles Darwin had a difficult time defining what a species was. Since then, many different ways of defining species have been developed so that there are more than 70 different definitions of species used to define any new ones. What this means is that species as a concept is largely a manmade idea. Nowadays, genetics is increasingly applied to defining a species. According to recent research, a new species can be defined if just 2 percent of their DNA is unique to the organism.

One of the difficulties of using genetics to define a species is that it tends to increase the number of species than can be defined with using morphology alone. These techniques can identify what are called cryptic species”, which look identical to other species but are actually genetically different. Mayr s concept of reproductive isolation has rapidly fallen apart.

One advantage of using genetics to define a species is that it is better at identifying endangered species that can get the protection they need under laws like the US Endangered Species Act. Without genetics, the identification of endangered species becomes almost impossible. A disadvantage is that it is a more expensive way of defining a species.