Studies of the genetic material of organisms and its changes over time can give rise to species. Species do not always look the same, and some species have apparent transitional characteristics between their ancestors and their descendants. This can make the study of the genetic material of organisms extremely complicated. The simplest approach to solving the problem of how to classify species is to recognize that all species share a common ancestry.
Through natural selection, there are species that are separated genetically by hundreds of thousands of mutations, from their common ancestor.
What is Evolutionary Biology?
Evolutionary biology is the study of life. It is the study of evolution and the effects of changes in living things on their traits and environments. The term was first used by Richard Dawkins in his book The Selfish Gene.
Evolutionary biology is the study of changes in the heritability of genetic patterns over successive generations. These patterns are the genetic expressions of maternal genes that are transmitted through reproduction. They are inherited from the mother and offspring both in humans and other animals. There are many types of genetic changes that occur both in humans and other animals. In all cases, these changes lead to a greater or lesser variation in expected trait values.
There are three basic categories of genetic changes that can occur in organisms. They are lateral gene transfer, horizontal gene transfer, and combination line changes. Lateral gene transfer occurs when one gene is acquired by another organism and carried on to the next generation. Horizontal gene transfer occurs when two or more genes are acquired by organisms from a previous generation. A combination line change is a single instance of horizontal gene transfer. All of these changes have
resulted in significant changes in living organisms.
An example of a lateral change can be seen in the case of the adaptation of fish to aquatic life. The ancestors of the modern guppy did not have eyes that would float, so they evolved into land-dwelling species with the ability to stay submerged under water. Guppies developed the ability to move about by swimming, which is the basis for the modern pool guppy. Another example of an adaptation is that of the foot. The modern human foot is much different from the feet of early humans. Those animals that had evolved into land-dwelling species had feet with large gaps between toes.
One must also recognize that there are species that have a very recent appearance in the fossil record. These fossils are often viewed as proof that species diversified immediately before becoming extinct. However, it is possible that the fossils show evidence of predating species that is still present in the gene pool. It is also possible that there are transitional species present, but their fossils are too young in time to allow useful comparisons to be drawn.
There are a number of
theories on the development of species, and some scientists even believe that the process of evolution can be directly linked to adaptation. If a species has a very fast rate of evolution and becomes extinct, it may have had a difficult time adapting to its new environment. On the other hand, if the adaptation is slow, it may not have been able to survive the competition. This theory provides a good explanation for the existence of many animals that look very similar to each other, but which are totally different in their needs and demands on the planet.
Adaptation, or change, is necessary for any species to exist. Without change, evolution will cease to exist. Some people think that evolution is directly linked to human beings; if two people are designed very similar, it would be expected that their children will also look very similar. This idea of evolution is the basis for many arguments about the origins of species, and it is one that underlie the entire subject of evolutionary biology.