An adaptation, or adaptive traitis an characteristic produced by the DNA or the interaction of the epigenome with the environment. While not all adaptations are entirely positive, for an adaptation to persist in an population should increase reproductive fitness or success. All offspring, whether formed sexual o asexuallyinherits its traits from its parents. In the asexual reproduction mostly identical clones are created.
Adaptation arises in asexual populations through mutations in DNADNA copying errors or the interaction of DNA with changes in the environment. In populations that reproduce sexually, adaptation arises through similar mechanisms, with the added effects of recombination during the meiosis and a molecule more complex DNA molecule. An adaptation can become vestigialor rendered useless, when changes in the population or environment render it useless. An adaptation also has certain trade-offs, such as the energy needed to create an adaptation, or the increase in the predation which can cause adaptation.
Types of adaptation
Mutation genetics and recombination
Deoxyribonucleic acid, or DNA, is the molecule that carries the information needed to create and maintain life. DNA is made up of a series of nucleotides4 small chemicals that are linked together. The sequence of these chemicals can be read by means of enzymes and specialised organelles within cells to produce new proteins. These proteins have various functions and determine how the cell functions. cell within its environment.
Since the first proteins and cellular components aggregated to form the first self-replicating cell, the interaction between DNA and the environment has driven adaptation. The single-celled organisms rely solely on molecular adaptation.because their basic structure prohibits the complex nature of developing new limbs and other structures. Instead, an adaptation in a prokaryote comes from advantageous mutations within its DNA that create new proteins or alter the effects of existing proteins.. The chemical reactions enabled by these proteins allow organisms to harvest nutrients, grow and divide more efficiently. Adaptation will persist in the population as long as fitness and reproduction increase.
At eukaryotes and multicellular species, the mutation process also drives adaptation. As in prokaryotes, DNA is controlled by a protein system that interacts with the environment, known as the epigenome. In eukaryotes, the complexity of this system has increased. An adaptation can affect the organism at every level, from creating a different way of replicating DNA to developing entirely new organelles and body structures. Studies have shown that mutations are often detrimentalor failure to adapt the organism to the environment. These mutations are not usually considered adaptations because they do not persist in the population at high levels. However, as the environment changes, maladapted traits may become beneficial and persist as an adaptation to a new setting.
Changes in the environment
Changes in the environment are the second main category of adaptation. In many cases, the epigenome is as or more important than DNA itself. Major environmental changes, such as a change in temperature or ocean acidity, can affect a large number of species. As the environment changes, proteins in organisms begin to function differently. Changes in DNA or in the way the epigenome interacts with the new environment can lead to novel adaptation. For example, life on Earth currently relies on a system of oxygen and dioxide carbon dioxidewhich their organisms use for energy and respiration.
Scientists have estimated that such an environment was not present until the photosynthetic.organisms began to create oxygen and deposit it into the atmosphere. The new chemicals in the atmosphere started a wave of adaptation that has led to the current biome we have today.
As more and more species differentiated, their interactions with each other began to drive adaptation as much as the simple composition of the atmosphere. Vast food webs developed and disintegrated over billions of years of life. These events were driven in part by the ability of organisms to adapt quickly to a situation and continue to reproduce. However, during many of these events, up to 90 percent of species did not survive the abrupt change. While adaptation can make organisms more competitive in an environment, it can also make them less flexible to survive in a changing environment.
Complex interactions between animals have also led to various forms of selection that affect and shape adaptation among the organisms involved. At sexual selectionFor example, differences and adaptive strategies between genders are not necessarily determined by the environment, but simply by the bizarre selection preferences of individuals attempting to reproduce. Many birds show highly coloured males, selected by dull-coloured females. Colour adaptation in males is a trait used to attract more females. The adaptation of females to dull colour, on the other hand, is the result of a selection more directional of the predator-prey relationship. Less colourful females are less likely to be detected by predators. Although these two adaptive traits contradict each other, they have persisted because they benefit males and females in different ways.
Examples of adaptation
Rhinoceros beetle
If you’ve ever seen a rhinoceros beetle, you’ve probably wondered what it uses those huge horns for. Below is a male rhinoceros beetle, with his distinctive headdress.
Like all arthropods the beetle is divided into segments. These various sections are very sensitive to adaptation. In the Rhino Beetle, the section of the head has developed these large spines. Male beetles use these large intrusions to fight each other in competition for females. It is presumed that ancestral beetles had little or no horn. As the beetles competed in pairs over many generations, mutations that created a better way to skin an opponent were rewarded. Over time, this adaptation of large horns emerged. Horns with the greater ability to defeat opponents allow those males to reproduce more and the adaptation will persist within the population.
Digestive tract in mammals
If you were to dissect various mammals, you would find something very peculiar about the size and composition of their digestive tracts. Carnivores, such as wolves and cats, have very short and simple digestive tracts. In fact, the more carnivorous an animal is, the shorter and simpler the digestive tract. Meat and animal products are easily digested. The adaptation of a short gut allows these animals to quickly process the energy from their meaty food before it begins to rot in their intestines.
Herbivores, on the other hand, have a short gut. digestive system long and complex. Some mammals, the ruminantshave multiple stomachs to process energy from grasses and other hardy plants. Non-ruminant herbivores have complex twists and turns in their guts, which increases the surface area and the amount of time food spends in the digestive tract. This adaptation allows the animals to process all the energy from the plant material. Interestingly, humans have a very complex gut, an adaptation for herbivores. Part of the complex story behind diet, nutrition and health probably stems from the fact that the Western diet focuses on meat, rather than the foods our bodies have adapted to eat.