Summary Of Origin Of Life Essay, Research Paper
While it is key to the study of evolution to develop a theory to explain how species can change over time, it must also be supported by evidence from the scientific study of the natural world. One of the difficulties faced by many theories, such as Lamarck s, was a lack of such evidence. Even Darwin’s theory, which is the most widely accepted today, had to be proved with scientific advances and fossil evidence in the scientific community.
Today, evidence for evolution comes from a few different angles. One is paleontology, which shows that gradual change in organisms can be seen in a fossil record. Paleontology is used to follow macroevolution, or large evolutionary trends. This is a key study of evolution because the discoveries of these fossils showed forms of animals that hadn t been seen before, and this began to cast serious doubt upon creationist theories. Also, it can be said that fossils provide the only direct evidence to the history of evolution.
Another type of study, biogeography, shows how the species might have spread to new habitats. Comparative anatomy, a technique that has been used since the very beginning of the study of evolution, allows for the comparison of dissimilar organisms to see whether they share a common ancestor. The most recent study, molecular biology, has shown us that even the molecules of life change over time, and these can be used to tell just how far back in history any two organisms last shared an ancestor.
Using these studies of the patterns of evolution, it has been found that some species evolve in relation to each other in other ways. Species that live in a close relationship with each other, like many predator and prey, often evolve adaptations to each other in a process called co-evolution. In predator-prey relationships, this evolution can escalate into rapid changes in offense and defense, known as a co-evolutionary arms race.
This evidence lead to an increased interest in the idea of evolution. Count George-Louis Leclerc de Buffon first suggested the idea that a species might change over time. Later his student, Jean-Baptiste Lamarck, who added details in the theory of how this took place, popularized it. However, it was not until 1859, when Charles Darwin wrote his book, On the Origin of Species, that the modern study of evolution began to take shape.
Charles Darwin is considered the father of the general study modern evolution. In On the Origin of Species, he stated that species had been changing since the beginning of time. He said that these changes occurred through time according to “survival of the fittest. This is also known as natural selection. Unfortunately, because the field of genetics had not yet been discovered, much less studied, Darwin could not explain how natural selection caused the change in the species he observed. In the early 1900’s, however, genetics became widely studied, and Darwin’s theory was more easily supported. In the 1940’s, scientists from the fields of experimental genetics, population genetics, natural history, and paleontology pooled the evidence from their fields to create a modern theory of evolution that included a genetic explanation for Darwin’s mechanism of natural selection. This theory, called the modern synthesis, is the most widely accepted theory of evolution today.
Another theory is the heterotroph hypothesis. This generally said that protocells could absorb macromolecules and ATP from an organic soup. Anaerobic cellular respiration evolved when ATP disappeared. Then, much later, autotrophs, cyanobacteria, evolved and produced O2. This, in turn, killed off intolerant forms and allowed for aerobic respiration. The result was a changed environment so abiotic polymerization could not occur. As O3 formed, high-energy source was no longer available.
Basically, the origin of life is still evolving in itself. There are many views of how life actually began, how it grew, and how it will end, and each theory has much merit. With the growth of scientific technology, these theories will advance.