The Evolution Site
The theory of evolution based on natural selection is the defining force of modern biology. It connects disciplines such as genetics, palaeontology and microbiology.
The study of evolution can be controversial and the misinformation that results can lead to confusion about its basic concepts. This site clarifies the most fundamental concepts.
What is Evolution?
Modern evolutionary theory focuses on the gradual and cumulative changes that occur in populations over time. These changes are the result of natural selection. This is a process that increases the number of organisms that have beneficial traits, which allow them to thrive and reproduce in specific environments. As a result, these organisms produce more offspring than those that do not have the beneficial characteristics. This causes the genetic changes that can eventually lead to the creation of new species.
The term "evolution" is often ascribed to the notion of "survival of the fittest," which implies that those people who are the most adapted to a specific set of environmental conditions will have an advantage over those who aren't adapted to the environment. This is just one of many ways in which evolution can occur.
Another popular way to use the term "evolution" is to suggest that a species will progress from one state to the next. This type of view of evolution could be referred to as anagenetic, or cladogenesis. This is not backed by the definition of evolution that is scientifically accepted. The scientific theory of evolutionary change is based on changes that occur in populations over time. These changes are the result of mutations that produce natural selection and genetic variation.
Some scientists, such as the great Charles Darwin, advocated this view of evolution. Others, including Alfred Russel Wallace, who developed the theory of macroevolution believed that this was the only way that the higher forms of life could have evolved from the lower forms.
A theory must stand against rigorous tests and evidence to be considered a theory. Evolution has stood the test of time and has been backed by numerous scientific disciplines ranging from geology to biology the sciences of astronomy to chemistry. In reality evolution is considered to be one of the foundations of science today, and it is supported by the majority of scientists across the globe. However, there are many misconceptions about the nature of the theory of evolution, specifically how it relates to religion.
What is the Theory of Evolution?
Evolution is a scientific explanation of how living things change over time. It is based on a few known facts: that more offspring are born than can be surviving, that individuals differ in their physical characteristics and that they are able to pass on traits to the next generation. These findings are supported by the increasing body of evidence from molecular biology, palaeontology functional morphology, climatology and geology.
The theory of evolution based on natural selection was developed independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century to provide an explanation for why organisms are adapted to their biological and physical environment. It is the most widely supported and validated theory in science. Its predictions were confirmed by the fact that, for instance, more complex organisms have fewer genetic mutations. The more successful an organism becomes in terms of its longevity and reproducing, the more likely it will transmit its genes to future generations.
Some people are against evolution because they believe that it implies that there is no reason to life. However, a lot of scientists who are also religious like the famous Cambridge Palaeontologist Simon Conway Morris, believe that evolution is not just compatible with belief in God but is enhanced by it (BioLogos 2014).
Many highly qualified evolutionary biologists have been involved in developing and testing the theory of evolution, including several highly respected evangelical Christian leaders. Many of these researchers contributed to the understanding of a vast array of phenomena, such as genomics and phylogenetics, and also the formation and function of fossils.
The word "theory" is sometimes used in a wrong sense to mean a speculation or guess, when in fact it refers to a scientific hypothesis that has been rigorously evaluated and refined over time. Scientists test hypotheses by repeating the experiments or observations that led them to their conclusions. Thus, the theory of evolution has been repeatedly borne 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 shift over time in the ratio of genetically distinct individuals within a particular species. This is the result of natural selection of individuals that are more adapted to their environment. The people who are more adaptable have higher chances of reproducing and survival. As more of these people survive and reproduce their genes are more prevalent within the population. This process is sometimes called "survival for the fittest."
According to the theory of evolution, mutations that lead to genomic variation are what drives evolution. These mutations could occur at random or under the influence of the environment. When mutations occur randomly and the frequencies of alleles can vary from generation-to-generation. When an alteration is beneficial, it can increase the frequency of the allele, which causes it to spread throughout the population.
Changes in the frequency of alleles can lead to new species in the course of time. The new species will grow and evolve into new forms. This process is known as macroevolution. page of new species is typically caused by changes in the environment that make certain resources accessible or creates new environmental problems. The evolution of finches in the Galapagos Islands, for example, is due to the availability of fresh food and the necessity to defend themselves from predators.
In a broader sense the term "evolution" refers to any change that takes place in the characteristics of organisms over time. The change could be subtle, like the development of a new color or dramatic, like the development of an organ.
Scientists who accept the theory of evolution generally recognize the importance of genetic change in generating evolution. They also agree that evolution is a process that takes place in time, typically over millions of years. However, they differ on the role of different factors that speed up or slow down the process, including the impact 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 support this is overwhelming.
What is the evidence for evolution?
Since Darwin's time, scientists have gathered evidence to support his theory of evolution. A portion of this evidence comes from fossils, which reveal the changing traits of living things over time. Similarities between living organisms as well as embryology, biogeography, and genetics are further evidence.
The evolutionary tree is the best method of proving evolution. It shows how different species are closely related. Another source of evidence is homologous structures, which share 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 grow to similar environments. For instance, arctic-foxes and Ptarmigans wear white seasonal pelts that blend into the snow and ice. This is a form of convergent evolutionary process which suggests that the species share ancestors.
Vestigial structures are another piece of evidence. These are a part of an organism that could have served a purpose in the past. For example the human appendix may be an oblique reminder of an organ that served to digest food. Natural selection causes these structures to shrink as they are no longer utilized.
Scientists have also gathered other evidence of evolution via observation and experimentation. The evidence for evolution can be divided into six categories: directly observable small-scale changes in biogeographic distribution and comparative anatomy, the fossil record, classification and genetics. Each of these provides convincing evidence that the evolution of life took place.
Many people have misconceptions about the theory of evolution. But, it's an actual fact. It is not a speculative theory, but a significant collection of evidence built on years of observation. Whatever people believe or don't believe about the theory of evolution scientists continue to research and discover new information to better understand the history of life on Earth. This knowledge will allow scientists to better understand how we can avoid future global catastrophes, and how best to make use of the resources of our planet. It will also allow us to better meet the needs of all the people living on the planet.