The Evolution Site
The theory of natural selection as the underlying principle of evolution is the defining factor in modern biology. It ties together disciplines as diverse as genetics, microbiology and Palaeontology.
The study of evolution may be controversial, and the misinformation that comes from it can lead to confusion about its fundamentals. This website helps to to clarify the fundamental concepts.
What is
Evolution
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The modern conception of evolution focuses on the gradual, cumulative changes that occur within populations over time. These changes are the result of natural selection. This is a process which increases the number organisms with beneficial traits, which help them to thrive and reproduce in specific environments. As a result, these organisms have more offspring than those that don't possess the beneficial traits. This could lead to a genetic mutation that could eventually lead to new species.
The term "evolution" is frequently associated with the idea of "survival of the fittest," which means that individuals who are best adapted to a specific set of environmental conditions will be more successful than those who aren't well-adapted. This is only one of the many ways that evolution can happen.
Another common way the word evolution is used to suggest that a species will eventually move from one state to the next state of being. This view of evolution can be described as anagenetic, or cladogenesis. The definition of evolution that scientists have developed does not support this idea. Instead the theory of evolution that is scientifically based concentrates on the changes that take place within populations over time and these changes are caused by mutations that produce genomic variation and natural selection.
Some scientists, including the great Charles Darwin, advocated this view of evolution. Alfred Russel Wallace who developed the macroevolution theory believed this was the only way in which the higher living forms could have evolved.
A theory must stand up to rigorous tests and evidence in order to be considered as a theory. The evidence for evolution has stood up to the test of time and has been supported by numerous studies in various scientific disciplines, from biology to geology to chemistry to astronomy. In actual fact evolution is regarded as one of the foundations of science today, and is backed by the vast majority of scientists around the world. However, there are many misconceptions about the theory of evolution, and particularly how it relates to religion.
What is the Theory of Evolution (Evolutionary Theory)?
Evolution is an explanation in science of how living things change with time. It is based on a range of well-established and observable facts that show that more offspring are often created than are likely to survive and that individuals differ from one another in their physical characteristics (phenotype) and that distinct traits have different rates of reproduction and survival and reproduction; and that these traits can be passed down to the next generation. These observations are supported by a growing body of evidence drawn from molecular biology, palaeontology climatology functional geology and morphology.
The theory of evolution by natural selection was developed independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century to explain how organisms adapt to their physical and biological environment. It is the most well-supported and validated theory in science. Its predictions were proved by the fact, for example that more complex organisms have less genetic mutations. In addition the more successful an organism is in surviving and reproducing in its ability to reproduce, the more likely it will be to pass its genes to future generations.
Some people oppose evolution because they believe it implies that there is no reason to life. However, a lot of scientists who are also religious believers, such as the prominent Cambridge Palaeontologist Simon Conway Morris, believe that evolution is not just compatible with belief in God but can be enhanced by it (BioLogos 2014).
In fact, a large number of highly skilled evolutionary biologists, some of who are revered evangelical Christian leaders, have been involved in the creation and testing of the theory of evolution. Many of these researchers have contributed to the understanding of a broad variety of phenomena, like phylogenetics, genomics, and the development and role of fossils.
The term "theory", which is often used incorrectly is a reference to a scientific hypothesis that has been tested and refined over a long period of time. Scientists test their hypotheses by repeating the experiments or observations that have led to them. The theory of evolution has been repeatedly tested out as have the corresponding theories of Copernican, germ theory, and atomic theory.
What is the Process of Evolution?
The process of evolution is the gradual change over time in the percentage of genetically distinct individuals within a certain species. This is the result of natural selection, which favors those who are better adapted to their environment. The individuals who are more adaptable have a higher chance of survival and reproduction. As more people survive and reproduce their genes are more common within the population. This process is sometimes referred to as "survival for the strongest."
According to the theory of evolution the mutations that cause genomic variation are the raw material for evolution. These mutations could occur randomly or be affected by the environment. If mutations are random, the resulting allele frequencies may vary from generation to generation. If a mutation is beneficial, it will increase the frequency of alleles which causes the allele to be spread across the population.
These changes in allele frequency can lead to new species in the course of time. The new species could develop further and evolve into newer forms. This process is known as macroevolution. The formation of new species is often due to changes in the environment which make certain resources available or creates new environmental problems. The evolution of finches in the Galapagos Islands, for example, is due to the availability of new food and the necessity to defend themselves from predators.
In a wider context, evolution is defined as any change that occurs in the nature of organisms over time. The change could be subtle, like the development of new colors or a dramatic change, such as the formation of an organ.
Scientists who accept evolution theory generally agree that genetic changes are crucial in the process of generating evolution. They also acknowledge that the process of evolution happens over a long time, typically millions of years. They differ in the importance of various factors that can accelerate or slow down the process. For instance the role of sexual selection, environmental pressures, and mutation bias. Despite these differences, the majority of scientists believe that evolution is happening and that evidence for this is overwhelming.
What is the evidence for evolution?
Since Darwin's time, scientists have collected evidence to support his theory of evolution. A portion of this evidence is derived from fossils which reveal the changing traits of living things over time. Similarities between living and non-living organisms as well as embryology, biogeography and genetics are further evidence.
The evolutionary tree is the most effective method to prove the existence of evolution. It shows how different species are closely related. Another evidence source is homologous structures, which share a similar structure in different species but have distinct functions such as the wings of birds and bats. The fact that different species evolve and adapt to a similar environment is another sign of evolution. For example, arctic-foxes and Ptarmigans sport white fur coats that blend into the snow and ice. This is a kind of convergent evolution, which suggests that the species had common ancestors.
Vestigial structures are a different piece of evidence. These are parts of an organism that may have served some purpose in the distant past. For example the human appendix is remnants of an earlier organ that served to digest food. These structures tend to shrink in size when they are no longer utilized, a process known as natural selection.
Scientists have also collected evidence for evolution by observing and testing. The evidence for evolution can be divided into six categories: directly visible small-scale changes in biogeographic distribution, comparative anatomy, the fossil record, genetics, and classification. Each of these categories provides convincing evidence for the evolution of life.
Although many people have misconceptions about the theory of evolution, it is an established fact. It is not a theory, but a powerful collection founded on decades of observation. Whatever people believe or don't believe about the theory of evolution scientists continue to research and discover new information in order to further comprehend the evolution of life on Earth. This knowledge will allow scientists to better understand how to prevent future catastrophes on the planet, and how best to make use of the resources on our planet. It will also allow us to better meet the needs of people on this planet.