Key Terms in Evolutionary Biology of Sex, Gender, and Sexuality: Adaptation

= Adaptation =

Definition
Adaptation (n, biology): a. any alteration in the structure or function of an organism or any of its parts that results from natural selection and by which the                                        organism becomes better fitted to survive and multiply in its environment.

b. a form or structure modified to fit a changed environment.

c. the ability of a species to survive in a particular ecological niche, esp. because of alterations of form or behavior brought about

through natural selection

definitions found at www.dictionary.com

Example(s) of use in context
In terms of evolutionary biology and ecologuy, an adaptation is an adjustment to the behavior and physiology of an organism to make it more adaptable to its environment. For every species, the characteristics for adaptation are very diverse, but are directed by the organisms gene. Adaptations can range from being a specialized limb that allows for specific movement or habitat alteration to specific behaviors due to a response from the environment. Adaptations have allowed for a diverse range of different shapes to arrive. Despite the different types of adaptations found in different forms, purposes, and organisms, the overall purpose of an adaptation is to guarantee that an organism and its genes will continue to exist. No matter how minute or useless an adaptation may be, it has come to exist as it allows the organism which it is characteristic to to survive.

Examples of adapation in wildlife
Adaptations are essential in the reproductive success of an organism. The ability to reproduce is perhaps the greatest adaptation available as it makes sure that a species continues to exist. A great example of an adaptation is the reproductive competition between male elephants in relation to the females reproductive cycle. A female elephant goes into estrous about 4 times a year, yet during these given times she is only fertile for 1-4 days. The male elephants go through a rise in testosterone at any given time during the year, a process known as musth. In the wild as observed in African Bush Elephants he'll be in close contact with any local females and will drive out any other males from his territory. While musth doesn't correlate with the females reproductive cycle, it is an adaptation to make sure there is variety in the gene pool by making males compete with one another over the greatest right to any animal, the right to reproduce. It appears that musth evolved as an adaptation for male elephants to be able to compete with one another over mating rights. There are quiet possibly other potential reasons as well.

There are several other more commonly seen examples of adaptations in the wild. Perhaps after reproductive adaptations are those that correspond to avoiding predation. One of the best forms of adaptation is camouflage. Many animals in the world are essentially defenseless and at the bottom of the food chain. This is often true of small birds, most rodents, many lizards, and especially of insects. The only form of defense that these animals have is to hide and hope predators do not see them. To do this, animals must look like the environment around them. An example of a local species that relies heavily on camouflage is the Grey Tree Frog (Hyla versicolor). This tree frog has virtually no defenses. Animals such as snakes, birds, and mammals would love to pick off this species one by one, only if they could see them. The grey tree frog can only look invisible. By doing this, its skin color is a mottled grey and looks almost like the lichen-covered substrate that it is often associated with. By looking just like the bark of a tree, this tree frog avoids being predated by looking invisible. The grey tree frog has also evolved the adaptation of being able to change its color to limited shades a dark grey and light grey. This helps even more when the animal needs to adjust to a different shaded tree.

In the long run, nearly every biological component of a living animal is an adaptation for its survival.

Image


A Grey Tree Frog camouflaging with a stump.

(www.njaudubon.org)

Author
Rory Kyle