Adaptive radiation
Adaptive Radiation

Adaptive Radiation: Definition, and 4 Examples

Adaptive radiation is a rapid increase in the number of species with similar ancestors, characterized by great ecological and morphological diversity. The driving force behind adaptive radiation is the adaptation of organisms to a new ecological context.

Adaptive radiation may not apply on a species scale, but it may also apply to higher taxonomic levels (large groups of organisms may also appear by adaptive radiation).

Adaptive Radiation Definition

Look around you, how many kinds of lives do you see, just sitting at your desk? If you pay attention to all the factors of bacteria, viruses, insects, plants and animals, you may be able to see a large number of species without even turning your head.

But how did all these species get here? Why do we see organisms continue to evolve as we do? One of the reasons organisms is related to adaptive radiation.

Adaptive radiation is the divergent evolution of a single lineage member into a variety of different adaptive forms. Usually adaptive forms differ in the use of resources or habitats, and these divergences occur in relatively short geologic time intervals.

In short, adaptive radiation is the tendency of a group of animals to develop in response to selective pressure and adapt to their environment in different ways.

Adaptive Radiation Definition Biology

In evolutionary biology, adaptive radiation is the stage in which organisms rapidly change into new forms, especially when environmental changes, make new sources and open up certain ecological niches. Starting from the same ancestors, this round produced speciation and phenotype adaptations of various species exhibiting different morphological and physiological characteristics of those who could utilize a variety of different environments.

Adaptive Radiation Example

Examples of adaptive radiation are all around us, in every living organism. No organism today is exactly the same as its original ancestors. Some species have changed significantly, such as diversification from one species of elephant and Hyrax.

Adaptive radiation causes the development of a divergent nature because it is a type of divergent evolution in which a group of organisms quickly diverge into a new species.

Adaptive radiation in Marsupials

One of the most common examples of adaptive radiation theory is the dispersion and diversification of marsupials (metatherians) into different orders and species. Marsupials have evolved from a single ancestor into a variety of forms. This has occurred on a continent completely cut off from the influence of many other species.

Adaptive radiation on Darwin Finch beak

The most commonly cited examples of adaptive radiation are what causes adaptive radiation to the beak of Darwin’s finches which was discovered during Darwin’s trip to the Galapagos archipelago. Speciation is the development of one of several new species in the evolutionary process, in which native species produce mutated forms that manage to survive in other environments due to these mutations. Adaptive radiation is the formation of species due to this speciation process.

Mammal Diversification

Adaptive radiation gives rise to mammalian expansion.

In primitive times, mammals are small and eat insects at night. Since they lived with dinosaurs, they found it very difficult to compete with them mainly due to huge differences in size.

After certain events occurred on planets that changed environmental conditions, mammals managed to develop skills that dinosaurs could not match: running, swimming, digging, becoming more agile and flexible.

The ability to adapt to changes is the reason why mammals survived and the dinosaurs became extinct. It seems that this ability helped greatly after the meteorite crashed 65 million years ago.

Under these new conditions, without great primitive animal competition, mammals manage to expand widely towards a large diversity of ecosystems.

Skin tone

The color of human skin is another example of adaptive radiation. This color is regulated the presence of melanin, a natural pigment with a high amount can absorb ultra rays and protect the dermis. A number of people with light skin specifically produce pheomelanin that has a reddish yellow color, while those with dark skin color in particular produce a dark brown color.

Under sunlight, it stimulates the synthesis of Vitamin D while folate decreases. Folate is needed as an early fetal development as well as partially regulated UV exposure. Too little or too much sunlight can enter folate levels. Meanwhile, the current theory about the human race that originated in Africa has been discussed using the model to predict adaptive radiation is helpful. In fact, the model can be used to approach 2 types of adaptive radiation.

We don’t have fossil evidence to prove that, most of the skin’s hair is much lighter when covered in a thick layer of hair or fur, different from mammals with thin coats. While migrating in savannas where sunlight is equaled, the hair is too much.

To be protected against UV sunlight the sun will be developed darker skin. Darker skin can reduce the deficiency of folic acid, which means higher pregnancy and birth rates while the constant equatorial sun production of vitamin D is quite good for its health.

Those who migrate in the northernmost areas of the arctic environment tend to be light in color, but darker than is sometimes expected based on that theory. This has been explained by their seafood diet by providing vitamin D food in winter while darker skin tone protects the population against the sun’s UV radiation by further reflected by the snow-covered landscape during the spring and summer months. Research has revealed that women have more folic acid deficiency than the population of women with light skin.


Last Updated on April 10, 2021 Reviewed by Market Health Beauty Team


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