Darwin’s Theory of Evolution

Evolution is the course in which a variety of organisms have adapted or changed from their previous forms. In other words, all living things share a common ancestor. This may be hard for some to believe but over the years scientists have gathered a great deal of evidence to prove that evolution does exist. We can see proof of this with , descent with modification, fossils, DNA, and natural selection.

Darwin’s theory of evolution says that all living things are related in some way and that each new organism is subtly different from its parents. This can be beneficial or detrimental for the offspring, so in an environment helpful traits become more common and unhelpful ones disappear. Random mutations in genes, ultimately end up in gradual changes and therefore the formation of recent species is understood as descent with modification. That is caused by natural selection, that takes those organisms that are less suited to their environments. Over time, these changes build up and result in the looks of recent species and new varieties of organisms. One change at a time, worms became fish, fish came ashore and developed four legs, those four-legged animals grew hair and eventually a number of them started walking around on two legs, referred to themselves as "humans" and discovered evolution. This can be hard to believe. It's one thing to understand that we simply aren't just like our parents, maybe your hair could be a completely different color, or you are a bit taller, however it's a lot more difficult to accept that you descended through many generations, from a worm.

Darwin's book On the Origin of Species tells the reader to look around their acquainted life. There, it's seen that offspring have characteristics passed on from organisms, ever-changing the character of the organism with time. Darwin was showing the method of cultivation and breeding. For generations, farmers and gardeners have purposefully bred animals to be larger or stronger, and plants to yield additional crops. Breeders work a bit like Darwin notioned evolution worked. Suppose you wish to breed chickens that lay additional eggs. First you need to notice those hens that lay more eggs than the others. Then you need to hatch their eggs, and make sure that the ensuing chicks reproduce. These chicks have to additionally lay more eggs. If you repeat the method with every generation, eventually you will have hens that lay much more eggs than wild chickens do. A feminine jungle fowl, which is the nearest wild relative of the domestic chicken, would possibly lay thirty eggs in a year, whereas farm hens can turn out 10 times as more. These changes from generation to generation area unit referred to as "descent with modification". A young chick can in many ways be almost like its parents, it'll be recognisably a chicken and it'll probably be like its parents and not other chickens, however it will not be identical. "That's what evolution is," says Steve Jones of University College London in the United Kingdom. "It's a series of mistakes that build up."

You might assume that breeding will only make a couple changes, however there looks to be no stopping to it. "No case is on record of a variable being ceasing to be variable under cultivation," wrote Darwin. "Our oldest cultivated plants, such as wheat, still often yield new varieties: our oldest domesticated animals are still capable of rapid improvement or modification." the answer is solely that evolution takes an extended time to form massive changes. To see proof of that, you have got to look at older records. You have got to look at fossils. Fossils are the remains of long-dead organisms, preserved in rock. As a result of rocks being put down in layers, one on top of the next, the fossil record is usually looked at in date order, the oldest fossils at bottom. Running through the fossil record makes it prevalent that life has changed over time. The oldest fossils of all are the remains of acellular organisms like bacteria, with a lot of more complex things like animals and plants showing up a lot later. Among the animal fossils, fish seem to appear a lot sooner than amphibians, birds or mammals. Our closest relatives the apes are solely found within the youngest rocks. By tediously studying fossils, scientists are been able to link several extinct species with ones that survive these days, generally indicating that one descended from another.

All living things store information in their DNA using the same genetic code, additionally a lot of genes found in human DNA are also found in the DNA of other creatures like bacteria and plants. This implies that all living things descended from a common ancestor. We can find out how organisms are related by comparing how any genes they share. For example, humans share 96% of their genes with apes, this suggests that we are close relatives. "Try to explain that in any other way than the fact that those relationships are based on a sequence of changes through time," says Chris Stringer of the Natural History Museum in London. "We have a common ancestor with chimpanzees, and we and they have diverged since then from that common ancestor."

Some people have the misconception that evolution makes species less primitive or improve. While this may the case sometimes, evolution is not always a process biological betterment. Jean-Baptiste Lamarck is the scientist who had the idea of evolution of organisms even before Darwin, but Lamarck thought organisms got better at living in their environments as if they inherently wanted to improve. According to Lamarck’s theory giraffes had long necks because their ancestors would stretch their neck to reach the tall trees and then the new long neck was passed to their offspring. Darwin had an alternative theory called natural selection, which gave a different reason to why giraffe had long necks. If an area had lots of trees, animals with the longest necks would be able to get food easier than the animals with short necks. After some generations animals would have longer necks than their previous ancestors did. The animals with the longer necks would survive better and eventually over many years giraffes necks would get longer. This is because the ones with short necks would tend to not produce offspring. Giraffes live in areas where leaves are high off the ground and the trees are tall, this is striking because they seem to be perfectly adapted. This may confuse people because it looks as if it were designed to be that way, but if you take a closer look you can see that it is little changes that build up to result in this way. We know that evolution is a fact of nature. It is the basis for life on Earth as we know it. We can put together all these pieces of evidence to show that life has evolved, and that evolution does exist.

Cite this page