Adaptive Radiation Evolution is defined as a process where animals of a particular kind change from their ancestral species to many new kinds, especially when a change occurs in the environment making many other sources available. It causes biological alterations and marks new environmental opportunities. It begins with one single ancestor that, with time, gets adapted to speciation and phenotypic changes of a row of species that exhibit similar morphological and physiological traits. An example of Adaptive radiation is finch speciation on the Galapagos birds.
Four basic features will help you to recognize adaptive radiation evolution:
It creates diversification in the entire biological speciation. The concept of evolution by means of adaptive radiation is important to understand the different ways the environment contributes to evolutionary divergence in a species and bring about changes to build the species according to the interaction of a species with its environment.
It is believed to be a fast development of various species from the same ancestor. Therefore, when an organism comes to a new area, environmental factors affect its survival chances.
Example: Anoles are lizards closely related to the Iguanas and are found in large numbers in various species on the Caribbean islands. These lizards have evolved separately to occupy various places on the islands or the environment they live in. One theory for this evolution suggests that lizards are brought to the island and find that there is a lot of food available with the absence of any predatory animal, which gives them time for evolution. The lizards spread out on the island where some find refuge on the treetops, some find food on the trunks, whereas some prefer to stay and hunt on the ground or in bushes. With time, these lizards develop traits that are helpful in their respective environment
Speciation is a word that is associated with the splitting or division of ancestry leading to the emergence of various kinds of new species from a common ancestor. The different reasons for speciation are:
Speciation has resulted from adaptive radiation. It deals with the evolution of more than one species from completely another species over the years. However, adaptive radiation is different from speciation in a few ways.
A group of living organisms changes very fast and gets converted into whole new species. This entire process is termed 'radiation'. Because new species got radiated from their common ancestor, this phenomenon occurs when a living organism enters a new environment that provides plenty of opportunities.
Adaptive radiation is a phenomenon where species take on different forms to adapt to a particular kind of environment.
This kind of evolution based on radiation includes organisms that have changed quickly and got fully changed into a new species. Scientists believe that adaptive radiation is one of the kinds of divergent evolution as the features between adaptive radiation and divergent evolution are almost the same.
In adaptive radiation, we can see signs of convergent evolution as well. In convergent evolution, different kinds of organisms share the same environment. This kind of change assists survival and also helps in modifying the morphology and analogous organs. When adaptive radiation is considered, one organism comes out of its natural habitat and goes to a new place with a different environment. When many organisms start to do the same, it becomes crucial for all those organisms to adapt to their new environment and evolve. This kind of adaptation that is seen in adaptive radiation is similar to that of convergence evolution.
As organisms get accustomed to new kinds of traits in their new environment and get isolated, they start to split from one another, leading to mass extinction. These mass extinctions occur due to climate changes, volcanic eruptions, impacts of asteroids, and at times due to a combination of these factors. When the environment and its conditions change faster than evolution, it results in mass extinction. The rate of extinction is greater than the rate of speciation.