Evolution is a process of change and development as organisms adapt to their environment and to changing circumstance through time. A variety of mechanisms have been identified as being involved in the process of evolution. This process does not take place in a steady and even manner, and eras of massive change have been identified in the fossil record during which a process called radiation has taken place, producing many new species and so many changes in a given population. Such a sudden and massive expansion of species has been identified in different parts of the world, such as the rapid growth in diversity of cichild fish in Lake Victoria in eastern Africa, where more than 500 species have evolved over the last 12,000 years. Scientists have sought to discover why such radiations occur.
Darwin explained the process of specialization and related it to adaptation. Specialization is the adaptation of a body part to a particular function or of a whole organism to a particular environment, and much of the diversity of life is expressed through specialization. Organisms are specialized in order to perform certain tasks in response to environmental conditions. Those organisms able to adapt to changing conditions and to develop a new functional use for an organ or body part will survive better than those that do not make such adaptation. The adaptation can be singular and minor or can involve the entire organism as it changes from one function or environment to another. A species is able to adapt when it has sufficient genetic variance to have what amount to a lot of "choices" so that some adaptations will be successful and will be passed on to subsequent generations. Darwin explained the idea of specialization by examining the facts as observed and developing theories to explain those facts. He observes domestic animals and the development of a breed over time and determines that the way human beings have used domestic an...