The Evolutionary Development of Adaptive Radiations - Essay Example

How does the environment cause the evolutionary development of adaptive radiations? The entire dynamics of the evolutionary process is based on environmental factors. Evolutionary concepts such as Darwinism and Lamarckism have recognized the role of environmental factors in the evolutionary development of a particular species. Perhaps the best example of this is the famous Darwin’s finches that belonged to the same ancestry but owing to the different seed types present in the different islands, they radially adapted for survival, thus giving rise to several species mildly different from the original ancestral ones.

Often owing to several environmental factors mostly disharmonic ones, speciation occurs, where a certain population of a species adapts to their new environment, develops a whole new niche and ultimately becomes a different species. The Galapagos Islands and the Hawaiian Islands are among places where adaptive radiations and convergence are noticed because these islands are relatively new than most Mainland and have radically different ecology and environmental niches. Wilson in his book the Diversity of Life, says that the 10,000 species of insects that now inhabit the Hawaiian islands have originated from a mere 400 species owing to adaptive radiation (Wilson, pp95).

In his book we find one of the best examples of adaptive radiation in the Hawaii’s. The Islands itself has different biodiversity and environment and genus Caconemobius have adapted themselves to different ecological niches in the same island. Some have left land existence and have become partial marine and live in boulders, another population of the same genus is blind and live in dark caves and yet another population of the same genus lives on lava flows (Wilson, pp96). This shows that the different population of the genus adapted to the new environment and developed a whole new niche for themselves and gave rise to a new species.

Cocos juvenile finches have the tendency to imitate feeding habits of warblers and sandpiper birds hence this is an embryonic state of radiation. If circumstances allow radiation Cocos finches will also meet adaptive evolution in the coming times. Another more livid example of adaptive evolution is the Lake Victoria cichlids. A study of these cichlids reveals the changes in each species and reveals the steps in adaptive evolution owing of changes in their environment (Wilson, pp109). An important part of biodiversity is the interactions between the abiotic and biotic elements in form of niches.

Each species has its own niche. Often species from different adaptive radiation converge and occupy the same ecological niche. This is where interspecific competition surfaces. The Tasmanian wolf of Australia and true wolf both occupy similar niches. Wilson in his book states that there is a limit to which two fully radiated species can coexist (pp 128). However over maturity of adaptive radiation species leads to imperfect convergent radiation like that seen in the Hawaiian woodpeckers (pp 100).

Adaptive radiation never ends; as long as environmental changes are met and species can successfully adapt, radiation from original species will occur. Wilson, Edward O. The Diversity of Life. Cambridge, Mass: Belknap Press of Harvard University Press, 1992. Print.