Charles Darwin's Theory Of Natural Selection

Evolution is a unit that is commonly studied under the topic of Biology. Biology is the study of living things, and evolution is the change in lineage of populations between generations. Biological evidence is a process of change when new species develop from existing species. On genetic terms, evolution is any change in the frequency of alleles in a population. Charles Darwin was an Englishman who was fascinated with nature, otherwise known as a naturalist. Darwin began a long voyage to explore the natural world. He collected fossils and sketched several animals. From this, he created the theory of evolution. A common ancestor is the most recent ancestral form or species from which two different species evolved. Evolution is certainly not something everyone agrees on. Millions of people have made theories, which are explanations of a part of the natural world that typically has many confirmed observations, laws, and verified hypothesis. People thought that Darwin’s theory was controversial because they believed that god was the one who made individual species. Darwin’s theory was considered to be extremely unorthodox. Evolution has impacted modern day life by changing different species to adapt to their environments.
There are several
different aspects that give evidence of evolution. Fossils are the remains or traces of ancient life. Today people take fossils for granted. But, fossils can create an image from billions of years ago. They answer questions that scientists have, and give additional clues about a species. Fossils tell us about when and where an organism lived, the behavior of the organism, and the history of the organism. For example, a layer on a rock gives a specific interval of geologic time. The oldest layers are at the bottom and the youngest are at the top. We can see how old a rock is from just counting it’s layers. 99% of all living creature’s organic macromolecules are made of Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, and Sulfur. This group of elements is commonly referred to as “CHNOPS”. Protein molecules are often very large and are made up of hundreds to thousands of amino acid units. 20 amino acids are combined in dissimilar ways to make up the 100,000 or so proteins in the body. Homologous structures are structures that originated from a common ancestor through divergent evolution. Analogous structures are structures from different ancestors that share similar characteristics from convergent evolution. Both structures are inherited from common ancestors, so they support the theory of evolution. Lastly, embryology is the type of biology in which it is concerned with the study of embryos and their development. Fossils, DNA, amino acids, “CHNOPS”, analogous and homologous structures, and embryology all support the theory of evolution.
Natural selection is the process when organisms who have better adapted to their environment survive and produce more offspring.
Two examples of natural selection are Darwin’s finches and Toxic Cane toads. Bigger birds promptly began eating all the larger seeds, pushing the smaller finches to specialize on smaller seeds. So, the beaks of the finches changed depending on their food source. Secondly, toads with long and strong legs have been rewarded. Toads with shorter legs have to stay behind. In this case, nature selects the longer-legged toads. These two species of animals show how natural selection occurs. Natural selection causes evolution to occur because the species are changing over time, depending on their
environment.
The founder effect is the loss of genetic variation when new colonies are formed by a very small number of individuals from the larger population. Polydactyly is a condition when one has extra fingers or toes. It is a symptom of the Ellis-Van Creveld syndrome. The syndrome is found among the older people of the Amish Pennsylvania. This is a population that experiences the founder effect. Another effect of population is the bottleneck effect. A bottleneck is an event when a population’s size is largely reduced. Northern elephant seals have less genetic variation than a population of southern elephant seals that was not so intensely hunted. The elephant seals are an example of the bottleneck effect. A mutation is any change in DNA, it can be positive or negative mutations can affect populations. When mutations occur in genes, they can give rise to new traits. Gene flow is the transfer of alleles and from one population to another. Geographic isolation is when a population of animals or plants are separated from exchanging genetic material with other organism of the same species. Geographic isolation separates the certain species from the gene pool, so it experiences different things and may eventually turn into a different species.
Evolution affects myself in several complex ways. The evolution of one species can contribute to the evolution of another species. Scientists now have the opportunity to research evolution everyday in ways they never could before. They can see how humans are changing everyday. Mutations, natural selection, embryology, gene flow, and other topics all contribute to evolution. It is nearly impossible for one person not to “believe” in evolution. There is so much proof that scientists have dug up from the ground. Fossils are able to tell us about vestigial structures and other bones. They give people the information of the ancient life that used to be. With some modifications, organisms have descended from species that lived billions of years ago.