Intraspecific Evolution

Intraspecific evolution is the evolution that is continually occurring within a species. When a species undergoes this type of evolution they are subject to many evolutionary pressures such as mutation, migration and selection. How the species reacts to these pressures effects their genetic variation, gene flow, chances of survival and all together their growth as a species. Whales are a group of species that have undergone many evolutionary pressures and many species have experienced bottlenecks with many different outcomes. A good example of a whale that has gone through intraspecific evolution is the killer whale, orca or Orcinus orca. The easiest way to tell how closely related animals within a species are is to look at their DNA and analysis

The cause for the bottleneck in the orca population was too old and widespread to be credited to human disturbance so it must have been caused by the last glacial maximum. The populations of orcas that recovered after the glacial period evolved to change. Some remained predators to fish and birds, others evolved to a different niche of marine mammals and sharks. These populations diverged due to geographic differentiation and this also could have affected the intraspecific evolution of these orcas. However even though the killer whales at different locations have similar genetic variation this variation is enough to separate them, partially because the kinship genetic variation within a specific population is even smaller. Although the current taxonomy and rate of intraspecific evolution within orcas is heavily debated the IUCN (international union for conservation of nature) released a statement implying that the status of Orcinus orca was in need of review and it is possible in the future that the group would be divided into subspecies or even species as new data is