The Evolution Site
The theory of evolution by natural selection is the defining force of modern biology. It connects disciplines such as genetics, microbiology and palaeontology.
The study of evolution may be controversial, and the misinformation that is generated can cause confusion about the fundamentals of evolution. This site can help explain the most important concepts.
What is Evolution?
Modern evolutionary theory is based on the gradual and cumulative changes that happen in populations over time. These changes are caused by natural selection, which increases the number of organisms who possess beneficial traits that help them survive and reproduce in a particular environment. These organisms produce more offspring because of the beneficial characteristics. This could result in a genetic mutation that may eventually lead to the creation of new species.
The term "evolution" is usually associated with "survival-of-the fittest" which implies that individuals who are more adaptable to specific environmental conditions will have a distinct advantage over those less well-adapted. In reality this is just one of the many different ways in which evolution can occur.
Another way to use the term "evolution" is to suggest that a species can change from one state to the next. This type of view of evolution is referred to as anagenetic or cladogenesis. This is not backed by the definition of evolution in science. Instead, the theory of evolution that is scientifically based focuses on changes that occur within populations over time, and these changes are the result of mutations that produce genomic variation and natural selection.
Charles Darwin was one of the scientists who supported this view. Others, notably Alfred Russel Wallace, who created the macroevolution theory and believed that this was the only way that the higher forms of life could be derived from 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 countless scientific disciplines from geology to biology, the sciences of astronomy to chemistry. Evolution is a cornerstone of science and is believed by a majority of scientists around the world. However, many people have misconceptions about the nature of the theory of evolution, particularly how it relates to religion.
What is the Theory of Evolution (Evolutionary Theory)?
Evolution is the scientific explanation for how living things change over time. It is based on a variety of well-established observable facts: that more offspring are often produced than can possibly survive in the long run; that individuals differ from one another in their physical characteristics (phenotype); that different traits confer varying rates of survival and reproduction and reproduction; and that these traits can be passed on to the next generation. These observations are backed up by an increasing body of evidence derived 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 late 19th century to explain why organisms are adapted to their physical and biological environments. It is the most widely supported and tested theory in science. Its theories have been proven out by the fact that, for example complex organisms are more likely to have less genetic mutations than simpler ones. In addition the more successful an organism is in reproduction and survival and reproducing, the more likely it is to pass on its genes to future generations.
Some people are against evolution based on the belief that it implies that there is no reason to life. However, a lot of scientists who are also religious such as the renowned Cambridge Palaeontologist Simon Conway Morris, believe that evolution is not just compatible with faith in God but also enhances it (BioLogos 2014).
Read Significantly more qualified evolutionary biologists have been involved in developing and testing the theory of evolution, including some respected evangelical Christian leaders. Many of them have contributed to the understanding of a wide variety of phenomena, such as phylogenetics, genomics, and the development and role of fossils.
The word "theory" is often used to refer to a guess or speculation however it actually is a scientific hypothesis that has been thoroughly developed and tested over time. Scientists test hypotheses through repeating the experiments or observations that led them to their conclusions. Thus, the theory of evolution has been repeatedly borne out as have the corresponding theories of Copernican, germ and atomic theory.
What is the Process of Evolution?
The process of evolution is a gradual shift in the genetically different individuals within a species over time. This change is the result of the natural selection of individuals that are more well-adapted to their environment. The more adapted individuals have higher chances of reproduction and survival. As more people live and reproduce their genes are more common within the population. This process is sometimes called "survival for the strongest."
According to the theory of evolution the mutations that cause genetic variation are the basic material for evolution. These mutations may occur at random or be affected by the environment. When mutations occur at random, the allele frequencies can vary from generation-to-generation. In contrast, when the mutation is beneficial, it will increase the frequency of the allele, causing it to spread across the population.
Over time, these changes in the frequencies of alleles can lead to the formation of new species. The new species will then develop and evolve into new forms. This process is known as macroevolution. The formation of new species is often caused by changes in the environment which makes certain resources available or creates new environmental problems. For example, the evolution of finches in the Galapagos Islands is a result of the availability of various food sources and the need to protect themselves from predators.
In a wider sense the term "evolution" can be described as any change in the characteristics of living organisms over time. The change could be minor like the development of a new coloration, or massive, for instance, the development of a brand new organ.
Scientists who accept the theory of evolution generally agree on the significance of genetic change in the process that causes evolution. They also believe that evolution is a process that occurs over time, usually over millions of years. They differ in the importance of various factors that may speed up or slow down the process. For instance the role played by sexual selection, environmental pressures, and mutation bias. Despite these differences, most scientists believe that evolution has occurred and that evidence for this is overwhelming.
What evidence do we have to support evolution?
In the decades since Darwin's time, scientists have collected evidence to support Darwin's theory of evolution. A portion of this evidence comes from fossils which reveal the changing traits of living things over time. Another evidence comes from similarities among living organisms, embryology, biogeography, genetics and comparative anatomy.
The evolutionary tree is the best way to prove evolution. It shows how species are related. Homologous structures are another proof. They have a similar structure but serve different purposes in different species, like the wing of a bird or bat. Evolution is evident in that different species adapt and develop to similar environments. For instance, arctic-foxes and ptarmigans grow seasonal white pelts to blend in with snow and ice. This is a form of convergent evolutionary mechanism, which suggests that the species share common ancestors.
Vestigial structures are another piece of evidence. These are parts of an organism which may have served a purpose in the distant past. For instance the human appendix may be a vestige of a once-used organ that served to digest food. These structures tend to shrink in size once they are no longer used, a process known as natural selection.
Scientists have also gathered other evidence for evolution through observation and experimentation. The evidence for evolution can be grouped into six distinct categories: directly observed changes at small scales, biogeographic distributions, comparative anatomy fossil records and genetics. Each of these categories offers solid evidence for the evolution of life.
Many people have misconceptions about the theory of evolution. However, it's a fact. It is not a theory but a powerful collection that is built on decades of observation. No matter what people believe or don't believe about the theory of evolution scientists continue to research and collect new data to better understand the history of life on Earth. This information will aid scientists to understand how to avoid future catastrophes on the planet and how to make the most of the resources on our planet. It will also enable us to better meet the needs of the people living on the planet.