Evolution of DNA
DNA has been an important discovery for many reasons, a key one being its relationship to evolutionary theory. Evolutionists have been particularly excited with DNA advances because the basis of DNA is such that it can be utilised to document the history of evolution. By comparing DNA sequences of genes from one organism to another, we can learn an enormous amount about their relationships. In fact, this learning goes far beyond what we can learn simply from morphology. At the same time, scientists are still aware that the DNA document of history, so to speak, is one that has gaps and is somewhat fragmented. This means that there must be awareness regarding the genetic changes that occur, otherwise we can become biased regarding how evolution occurred.
Using DNA to Study Variation Among OrganismsDNA has been used to study many aspects pertaining to the evolution of organisms. By investigating variation among species and the structure of different populations, scientists have learned a great deal about molecular evolution. Evolutionists look for specific patterns of DNA variation and then make logical inferences from the information. There is an enormous amount of variation within species, which does include humans. Your DNA will be different from another person's DNA. As such, two individuals cannot share the same DNA, although this does not hold true for identical twins. The result is that phenotype variation occurs. This type of variation refers to differences in the appearance and the behaviour of organisms within the same species.
Genetic Mutations and RecombinationVariation can arise though mutations, which happen when DNA copying is faulty and there is a difference between parent and offspring genes. While a mutation can be 'fixed' by DNA repair systems, some may have negligible effects. Others, however, can impact large pieces of DNA and lead to changes within a species. Recombination occurs when two parent genes are essentially mixed up to create an offspring, a common occurrence in asexual reproduction. Although the parents typically are members of the same species, occasionally genes can be moved between less related organisms. This is more likely to occur in organisms such as bacteria.
Evolution of the Genetic Code and Genetic RelatednessDNA actually has numerous roles, the most well-known being its ability to code for proteins. This coding, however, is quite different from DNA's function in terms of our genetic code. Our genes include those that are expressed; they also have special sequences that dictate precisely when and where DNA is transcribed into another molecule called RNA for the creation of proteins. Our genetic code is the system that allows an RNA strand to be translated into a necessary sequence of amino acids.
Genomes for organisms hold a significant amount of evidence for evolution given that living species share the commonality of basic hereditary systems that use DNA or RNA to pass on genes from parent to offspring. By quantifying the similar aspects as well as the differences between and within species, scientists can assess the relationships between species. This tells us which species are closely or distantly related. This pattern then relays what is essentially Darwin's branched out tree for life.
Investigating Genetic SimilaritiesDNA supports genetic similarities and these similarities help researchers to understand effects from human genes through research on other species. For instance, there are genes governing DNA repair systems in bacteria, flies and rodents, which have been found to impact cancers in humans.
Evolution is certainly an area that generates debate although the scientific community at large is confident in the theory of evolution and it is mandated in the United Kingdom curriculum as well as most other places in the world. The discovery of DNA has supported evolutionary theory and our continued understanding of this molecule can help scientists to make predictions about the direction of evolution in the future.