The theory of evolution by natural selection is the unifying force of modern biology. It brings together disciplines like microbiology, palaeontology, genetics and palaeontology.
The study of evolution may be controversial and the misinformation that comes from it can lead to confusion over its basic concepts. This site can help clarify essential concepts.
What is Evolution?
Modern evolutionary theory focuses on the gradual and cumulative changes that happen in populations over time. These changes are the result of natural selection, which increases the number of organisms who have beneficial traits that enable them to live and reproduce in a particular environment. The organisms that have these traits produce more offspring because of their positive characteristics. This leads to a genetic change that can eventually lead to the creation of new species.
The term "evolution" is frequently associated with the idea of "survival of the fittest" which implies that people who are the most adapted to a particular set of environmental conditions will have an advantage over those who are not well-adapted. This is just one of many ways that evolution could happen.
Another popular way in which the term "evolution" is used to suggest that a species will eventually change from one state of being to the next state of being. This view of evolution can be referred to as anagenetic, or cladogenesis. This is not backed by the scientific definition of evolution. The scientific theory of evolutionary change is based on changes that occur in populations over time. These changes are the result of mutations that result from natural selection and genetic variation.
Charles Darwin was one of the scientists who backed this idea. Alfred Russel Wallace who developed the macroevolution theory believed that this was only way the higher living forms could have evolved.
To be able to be referred to as a theory, it has to be capable of surviving rigorous tests and evidence. Evolution has stood the test of time, and has been proven to be valid in countless scientific disciplines from geology to biology, chemistry to astronomy. Evolution is the foundation of science and is believed by a majority of scientists across the world. Many people have misconceptions regarding the nature of evolution theory, especially how it relates with religion.
What is the Theory of Evolution (Evolutionary Theory)?
Evolution is a scientific explanation of how living things change over time. It is based on a few known facts: that more offspring are created than can survive and that different individuals have their physical characteristics, and that they are able to pass on traits to the next generation. These observations are supported by a growing body of evidence derived from molecular biology, palaeontology and climatology functional morphology geology.
Charles Darwin and Alfred Russel Wallace independently conceived the theory of evolution through selection in the middle of the 19th century as an explanation why organisms adapt to their physical and biologic environments. It is the most well-supported and validated theory in science. Its predictions were proved by the fact, for example that more complex organisms are less susceptible to genetic mutations. In addition the more efficient an organism is in being able to reproduce and survive and reproducing, the more likely it will be to pass on its genes to the next generation.
Some people are against evolution because they believe it suggests that there is no purpose to life. However, many scientists who are also religious believers like the famous Cambridge palaeontologist Simon Conway Morris, believe that evolution isn't just compatible with faith in God but also enhances it (BioLogos 2014).
In actual fact, a significant number of highly trained evolutionary biologists, including some 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 range of phenomena, like phylogenetics, genomics and the formation and function of fossils.
The word "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 hypotheses by repeating the experiments or observations that led them to them. Therefore, the theory of evolution has been repeatedly proven out and so have the 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 for their environment. The more adapted individuals have a higher chance of survival and reproduction. As more individuals survive and reproduce their genes are more common in the general population. This process is sometimes referred to as "survival for the strongest."
According to the theory of evolution the mutations that cause genetic variation are the primary reason for evolutionary change. These mutations can occur at random or be affected by the environment. When mutations are random the frequencies of the resulting alleles may differ from generation to generation. When an alteration is beneficial, it will increase the frequency of the allele, which causes it to spread throughout the population.
These changes in allele frequency could lead to new species in the course of time. The new species will grow and evolve into new forms. This is a process known as macroevolution. The creation of new species is typically caused by changes in the environment which makes certain resources available or creates new environmental challenges. The development of finches in the Galapagos Islands, for example, is due to the availability of new foods and the need to defend themselves against predators.
In a broader context it is possible to define evolution as any change in the characteristics of living organisms over time. The change could be minor, such as the development of a new coloration or massive, for instance, the development of a brand new organ.
Scientists who believe in the theory of evolution generally recognize the importance of genetic change in the process that causes evolution. They also agree that the process of evolution occurs over a lengthy period of time, usually millions of years. However, they differ on the role of various factors in speeding or slowing the process, like the influence of environmental pressures sexual selection and mutation bias. Despite these differences most scientists are still convinced that evolution is real and that the evidence to prove it is overwhelming.
What is the Evidence of Evolution?
Since Darwin's time scientists have collected evidence to back his theory of evolution. This evidence is gathered from fossils which show the evolution of organisms over time. Another evidence comes from the similarities between living organisms, embryology, biogeography, genetics and comparative anatomy.
The evolutionary tree is the best method of proving evolution. It shows how different species are related. Another way to prove it is homologous structures, which have a similar structures in different species but perform distinct functions like the wings of bats and birds. Evolution is also evident in the fact that different species adapt and develop to similar environments. For example, arctic foxes and ptarmigans develop seasonal white pelts that blend in with snow and ice. This is a kind of convergent evolutionary process, which suggests that the species share common ancestors.
Another source of evidence is the existence of vestigial structures. These are unutilized parts of an organism that may serve a purpose in the distant ancestor. For instance the human appendix may be a vestige of a once-used organ that was used to digest food. These structures tend to shrink in size when they are no longer used in a process called natural selection.Scientists have also gathered additional evidence for evolution through observation and experimentation. The evidence for evolution can be grouped into six distinct categories: changes that can be observed at a small scale, biogeographic distributions and comparative anatomies, the fossil record and genetics. Each of these provides compelling evidence that the evolution of life has taken place.
Many people have misconceptions about the theory of evolution. But, it's a fact. It is not a theory, but a significant collection that is based on years of observation. Scientists continue to collect and study new information to better understand the evolution of Earth's existence, regardless of whether people believe in the theory of evolution or not. This information will allow scientists to better understand how to prevent future global catastrophes, and how to use the resources available on our planet. This information will also allow us to better meet the needs and wants of all the people living on our planet.
