Visit the link for a brief overview of how animals adapt to their habitat. Did you know that animals camouflage themselves so they can adapt to their environment? Adaptation can protect animals from predators or from harsh weather. Many birds can hide in the tall grass and weeds and insects can change their colour to blend into the surroundings. This makes it difficult for predators to seek them out for food. Some animals, like the apple snail, can survive in different ecosystems- from swamps, ditches and ponds to lakes and rivers.
This is often the case in swamps and shallow waters. To know more about how the apple snail can survive in different habitats visit the link. In the harsh cold climate of Alaska, the animals have learnt to adapt to the weather by storing food in their body and protecting themselves from the cold with thick furs.
Human inhabitants in Alaska have also learnt to cope with the environment by building shelters that insulate and hold the heat, and yet do not allow the structure to melt. To know more about this go to this website. Echolocation in bats is an adaptation for catching insects. The answer: a lot of things. One example is vestigial structures. Fish species that live in completely dark caves have vestigial, non-functional eyes.
So fish with better sight no longer out-competed fish with worse sight. Many of the features of organisms that most impress us are adaptations. Learn about what evidence biologists look for to determine if a trait is an adaption and common misconceptions regarding adaptations.
However, not all traits of organisms are adaptations. Read more about the sorts of traits that are not adaptations and one particular type of non-adaptation, exaptation. Skull sutures in mammals appear as an adaptation for birth since they allow the skull to deform when passing through the birth canal a tight squeeze. But reptiles and birds have them and they hatch out of eggs.
Sutures evolved in one context allow for growth of brain, head but are an exaptation for birth in mammals they do allow for the head to change shape during birth which is adaptive. Isolating mechanisms that prevent gene flow between incipient species. These evolved in allopatry prior to any exposure to the sister taxon; isolating mechanisms may undergo subsequent adaptive changes after being challenged by the related species.
In all these cases the historical origin is quite distinct from the current utility. Exaptation also allows for the evolution of traits that originally had no "adaptive" function, but later get coopted for a function. The Adaptationist Program as it has been called by Gould and Lewontin Section reading seeks to find adaptive explanations for every characteristic of the organism.
Some things are not "for" the "purpose" or "role" they seem to be filling e. Think of your chin ; it's not "for" something, it is there due to differential growth rates of two growth fields dentary and maxillary of your skull. Its just there. The striking pattern of white triangles on the Conus shell: looks like it is "for" something but they live under the sand and mud and are not visible.
Could be due to chemistry of shell deposition or might have been "useful" in the shell's ancestor. Notion of optimality needs to be considered in a historical context: again, consider current utility vs.
Another important point contra the Adaptationist Program is that some traits may not be capable of achieving "maximal adaptedness" selection acts on the entire phenotype debatable sensu units of selection; later and phenotypes are compromises.
Orians' central place foraging model: bird sits in middle of territory, may fly a certain route depending on availability and size of food items. Could design and optimal foraging strategy BUT, when the birds leaves nest, young are available for predation. Foraging strategy may not be the best foraging strategy, but the best compromise given predation risk.
Green sea turtle : excellent swimmer; terrible digger not designed for it but must use flippers to dig hole for laying eggs. Flippers are not "optimal" for digging, but they work. Phenotypes as compromises underscores the importance of constraints. Evolution of one trait can be constrained due to correlation among traits: selection for body weight in broiler chickens: get more fat with it; selection for increase milk yield in cows: more milk with higher water content ; selection for yield in soybeans: get less protein per bean; selection for nicotine content in tobacco: tar content increases.
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