The theory of evolution by natural selection is the unifying force of modern biology. It ties together disciplines as diverse as genetics, microbiology, and palaeontology.
However, the study of evolution is often controversial, and the misinformation that results can confuse people about its basic concepts. This site explains the fundamental concepts.What is Evolution?
The modern understanding of evolution focuses on the gradual change that occurs within populations over time. These changes are the results of natural selection. This is a process which increases the number organisms with beneficial traits, which help them to thrive and reproduce in certain environments. This means that these organisms have more offspring than those that don't have these beneficial traits. This could result in a genetic mutation that may eventually result in new species.
The term "evolution", is often associated with "survival-of-the most fittest" which implies that individuals who are more adjusted to certain conditions will have a distinct advantage over those who are less well-adapted. In reality it is only one of many ways that evolution could occur.
Another way to use the term "evolution" is to suggest that species will progress from one state to the next. This view of evolution can be described as anagenetic or cladogenesis. The definition of evolution in science does not support this view. Instead the theory of evolution that is scientifically based concentrates on the changes that happen within populations over time and these changes are caused by genetic mutations and natural selection.
Some scientists, such as the great Charles Darwin, advocated this theory of evolution. Others, such as Alfred Russel Wallace, who created the macroevolution theory, believed that this was the only way that the higher forms of life could have evolved from the lower forms.
A concept must be able stand up to rigorous tests and evidence in order to be considered as a theory. Evolution has stood the test of time and has been backed by numerous scientific disciplines ranging from geology to biology, from astronomy to chemistry. In actual fact, evolution is accepted as one of the cornerstones of science today and is backed by the vast majority of scientists worldwide. However, there are many misconceptions about the theory of evolution, and particularly how it is related to religion.
What is the Theory of Evolution?
Evolution is the scientific explanation of how living things change over time. It is based on a range of well-established and observable facts such as the fact that more offspring are often created than are likely to survive; that individuals differ from one another in their physical characteristics (phenotype); that different characteristics result in different rates of survival and reproduction; and that traits can be passed on to future generations. These findings are backed by a growing amount of evidence from molecular biology, palaeontology and climatology functional geology and morphology.
The theory of evolution based on natural selection was developed independently by Charles Darwin and Alfred Russel Wallace in the late 19th century to provide an explanation for the reason that organisms are adapted to their physical and biological environment. It is the most well-supported and tested theory in the field of science. Its predictions have been borne out by the evidence that, for instance, more complex organisms tend to have fewer genetic mutations than simpler ones. The more successful an organism becomes in terms of its longevity and reproducing, the more likely it is to transmit its genes to future generations.
Some people are against evolution because they think it implies that there is no reason for existence. However, many scientists who are also religious, such as the prominent Cambridge Palaeontologist Simon Conway Morris, believe that evolution is not only compatible with belief in God but can be enhanced by it (BioLogos 2014).
In actual fact, a significant number of highly qualified evolutionary biologists, including some who are revered evangelical Christian leaders are involved in the development and testing of the theory of evolution. Many of these researchers have contributed to the understanding of a wide range of phenomena, such as phylogenetics, genomics and the formation and function of fossils.
The word "theory", which is often misused is a reference to a scientific hypothesis that has been tested and refined over time. Scientists test hypotheses by repeating the experiments or observations that led them to them. Therefore the theory of evolution theory has been repeatedly confirmed, as have the corresponding theories of Copernican theory, www.Evolutionkr.kr atomic theory, and germ theory.
What is the Process of Evolution?
The process of evolution is a gradual change in the proportions of genetically diverse individuals within a species over time. This change is the result of the natural selection of individuals that are more adapted to their environment. The individuals who are more adapted have higher chances of reproduction and survival. As more of these people survive and reproduce, their genes become more common in the population. This is sometimes called "survival of the most fittest."
According to the theory of evolution, the mutations that produce genetic variation are the basic material for evolution. These mutations may occur randomly or be influenced by the environment. When mutations occur at random, the allele frequencies can vary from generation-to-generation. In contrast, when an alteration is beneficial, it can increase the frequency of the allele, causing it to spread throughout the population.
The changes in frequency of alleles could lead to new species as time passes. The new species can then continue to evolve and become newer forms. This process is called macroevolution. The formation of a new species is usually due to changes in the environment which make certain kinds of resources available or cause new environmental challenges. For example, the evolution of finches in the Galapagos Islands is a result of the availability of various food sources and the need to defend themselves from predators.
In a broader context, evolution can be defined as any change in the character of living organisms over time. The change could be small like the development of a new coloration or massive, for instance, the formation of a new organ.
Scientists who believe in the theory of evolution generally agree that genetic changes are essential in generating evolution. They also acknowledge that the process of evolution occurs over a lengthy period of time, usually millions of years. They differ on the importance of various factors that can accelerate or slow down this process. For instance, the role of sexual selection, environmental pressures and mutation bias. Despite these differences, the majority of scientists still believe that evolution is real and the evidence in support of this is overwhelming.
What is the Evidence of Evolution?
Since Darwin's time, scientists have gathered evidence that supports his theory of evolution. The evidence comes from fossils that demonstrate the evolution of living organisms over time. Similarities between living and non-living organisms as well as embryology, biogeography, and genetics are also evidence.
The primary evidence of evolution is in the evolutionary tree, which shows how different species are connected. Homologous structures are another proof. They share a common structure but perform different functions in different species, like the wing of a bird or bat. Evolution is evident in the way that various species adapt and evolve to similar environments. For instance, arctic foxes and ptarmigans grow seasonal white pelts to blend in with snow and ice. This is a kind of convergent evolution that suggests that the species had common ancestral ancestors.
Vestigial structures are a different piece of evidence. These are a part of an organism that could have served a purpose in the past. For example the human appendix is a vestige of a once-used organ used to digest food. These structures tend to shrink in size as they are no longer utilized in a process called natural selection.
Scientists have also gathered other evidence for evolution through observation and experimentation. The evidence for evolution can be classified into six different categories: directly observed changes at a smaller scale, biogeographic distributions, comparative anatomy, the fossil record and genetics. Each of these categories offers convincing evidence for the evolution of life.
Many people have misconceptions about the theory of evolution. However, it's an established fact. It is not a speculative theory, but a powerful collection that is built on years of observation. Regardless of what people believe or don't believe about the theory of evolution scientists continue to research and discover new information in order to further understand the history of life on Earth. This information will help scientists to better understand how to avoid future catastrophes on the planet, and how to best utilize the resources of our planet. This will allow us to better serve the needs of people living on the planet.
