Adaptive Radiation Evolution: Definition, Causes, Examples

Adaptive radiation is defined as the rapid diversification of a single ancestral species into multiple species, each adapted to unique environments. It explains the process through which organisms evolve and have different traits to occupy specific ecological niches, like adaptive radiation in the beaks of birds. In this article, adaptive radiation, causes of adaptive radiation, and adaptive radiation examples are discussed. Adaptive radiation is a topic of the chapter Evolution in Biology

Latest: NEET 2024 Paper Analysis and Answer Key 

Don't Miss: Most scoring concepts for NEET | NEET papers with solutions

New: NEET Syllabus 2025 for Physics, Chemistry, Biology

NEET Important PYQ & Solutions: Physics | Chemistry | Biology | NEET PYQ's (2015-24)

This Story also Contains

1. What is Adaptive Radiation?
2. Causes of Adaptive Radiation
3. Adaptive Radiation Examples

What is Adaptive Radiation?

Adaptive radiation refers to the evolution of several species that originated from a common ancestral source, in which each new species will be adapted to a different environment or resource. Adaptive radiation is essentially a process of producing different species from one lineage concept essential to answering how biodiversity first arises.

Adaptive radiation remains critical since it allows the contribution of enormous biodiversity and the development of novel species with highly specialised characteristics for better living. In this way, it is a good example of mechanisms showing how environmental factors and ecological opportunities drive the evolutionary process toward great diversity of life forms and their adaptation.

Causes of Adaptive Radiation

There are many causes of adaptive radiation. Some of them are discussed below.

• Change in environment or climatic conditions
• Due to the arrival of a new predator in the place where the species is living
• When there is no availability of food
• Due to migration
• Increase of new ecological opportunity
• Due to the changes in genetic characteristics
• Due to mutation pressure, natural selection, genetic drift, artificial selection, etc.

Read More:

• MCQ Practice on Adaptive Radiation
• Evolution
• Evidence of Evolution
• Human Health and Disease

Adaptive Radiation Examples

Notable examples of adaptive radiation are those of Galápagos finches, Hawaiian honeycreepers, cichlid fishes in the African Great Lakes, and Anolis lizards in the Caribbean.

Adaptive Radiation in Beaks of Birds

A great example of adaptive radiation is the Galápagos or Darwin finches. The species evolved from a common ancestor but developed many different beak shapes and sizes to eat seeds, insects, and nectar. In this way, they evolved to fill many ecological niches on the islands.

The diagram below shows the adaptation for better survival:

Hawaiian Honeycreepers

Hawaiian honeycreepers evolved to over 50 species from one ancestral species. These birds evolved different beak forms and sizes from the model itself, adapted to live life as insects, nectar, or seed feeders.

Cichlid Fishes of African Great Lake Areas

Cichlid fishes of the African Great Lakes have undergone large amounts of adaptive radiation. Hundreds of cichlid species have since then been adapted into different feeding strategies, habitats, and behaviours.

Anolis Lizards in The Caribbean

Anolis in the Caribbean have diversified into numerous species, each adapted to its ecological niche, such as a habitat on tree trunks, branches, or grasses. This gives rise to this adaptive radiation with a wide range of morphological and behavioural traits.

Read More:

Recommended video on Adaptive Radiation