Adaptive radiation, Mosaic Evolution


Adaptive radiation occurs when a species is exposed to a new environment or when the environment changes. It is a key process in the evolution of biodiversity and is driven by natural selection and the availability of new resources.

When a single species or group of closely related species diversifies into many diverse forms, each one adapted to a unique ecological niche, it is called adaptive radiation.This can cause the species to evolve in order to better survive in the new environment.

  • This process is often seen in the evolution of species on islands, where the species must adapt to different conditions in order to survive.

  • For example, when a species is exposed to a new island, it may evolve to become better suited to the new environment. This could include changes in body size, coloration, or behavior. The process of adaptive radiation can be seen in many different species and it is an important process in the course of evolution.


The concept of adaptive radiation was first proposed by Charles Darwin in his book Origin of Species, where he suggested that a single species could give rise to multiple species adapted to different environments.

Adaptive radiation has been observed in many different species, including birds, mammals, reptiles, amphibians, and insects. For example, the Galapagos finches where a single species of finch colonized the Galapagos Islands and then diversified into multiple species adapted to different ecological niches form a classic example of adaptive radiation,

Similarly, the cichlid fishes of Lake Victoria are another example of adaptive radiation, where a single species of cichlid fish has diversified into hundreds of species adapted to different habitats. Adaptive radiation has also been observed in plants, where a single species of plant has given rise to multiple species adapted to different environments.

The following traits are generally observed to identify an adaptive radiation

  • A recent shared ancestry can be drawn out between the species.

  • Phenotype of the species and its environment are inked through morphological and physioogical traits.

  • The evolutionary trait provides an advantage to the species in that particular environment.

  • Multiple species have evolved rapidly during a time period.

Taxonomic Range

Taxonomic range, or taxonomic diversity, is the number of distinctive species found within a certain taxonomic category. The degree to which the species within an ecosystem are able to adjust to new conditions is a good indicator of the ecosystem's overall health.

To a large extent, we may attribute the growth in the number of recognised taxonomic groups to the process of adaptive radiation. When one species or group of species diversifies into several new species, each of which develops into a separate niche, the total number of species in that taxonomic category increases.

There have been numerous ecosystems, from the tropics to the polar regions, that have experienced a rise in species variety as a result of adaptive radiation.

Mosaic Evolution in hominins

  • When the various biological components of a species evolve at various speeds, the emerging creatures display a mosaic of both innate and acquired traits. Mosaic evolution refers to this phenomenon in which a species undergo evolutionary change at different rates.

  • The term "Mosaic evolution" was originally used by American paleoanthropologist, Milford Wolpoff in the 1970s.

  • The concept of mosaic evolution is often used to study the way hominins have changed over time. It is widely held that the need to adapt to different habitats was the primary factor in this development.

  • For instance, they must have had to modify their diets, habitats, and even defence mechanisms in response to climatic change. It's possible that certain hominins developed with a more capacious brain while others gained greater leg length.

  • Hominins were able to successfully adapt to and thrive in their environment by combining traits from a variety of other species.


  • The term "adaptive radiation" describes the process through which a single species or small group of species diversifies into a wide variety of forms, each adapted to a different environmental niche.

  • Adaptive radiation was first proposed by Charles Darwin in his book Origin of Species. This is the process by which a single species can give rise to other species that have adapted to different environments.

  • Taxonomic diversity, also known as taxonomic range, refers to the number of different species that fall under a certain taxonomic umbrella. The resilience of an ecosystem may be gauged by looking at how well its species adapt to changing conditions.

  • Evolutionary change in hominins is often referred to by the phrase mosaic evolution, Attempts to adjust to new environments are thought to have been the driving force for this transformation.

  • When different parts of a species evolve at different rates, the resulting organisms exhibit a fascinating blend of inherited and acquired characteristics. This process, in which members of the same species experience evolutionary change at widely varying rates, is known as "mosaic evolution."


Q1. What are the benefits of mosaic evolution?

Ans. Mosaic evolution can be beneficial for organisms because it allows them to adapt quickly to changing environments. It also allows them to develop new traits that can give them an advantage in their environment.

Q2. How does an ecological niche affect a species?

Ans. An ecological niche affects a species by determining its ability to survive and reproduce in its environment. It also affects the species’ interactions with other species in the environment, as well as its ability to compete for resources.

Q3. What are some examples of adaptive radiation?

Ans. Finches on the Galapagos Islands, cichlid fish in African lakes, and mammal development following the loss of the dinosaurs are all examples of adaptive radiation.