The Evolution Site
The theory of evolution by natural selection is the unifying force of modern biology. It brings together disciplines such as microbiology, palaeontology, genetics and palaeontology.
The study of evolution may be controversial, and the misinformation that comes from it can lead to confusion about its fundamentals. This site explains the fundamental concepts.
What is Evolution?
The modern conception of evolution focuses on the gradual, cumulative changes that occur within populations over time. These changes are caused by natural selection, a process that increases the amount of organisms that have beneficial traits that help them survive and reproduce in a specific environment. This means that these organisms leave more offspring than those who don't possess the beneficial traits. This could cause a genetic change which could eventually lead to new species.
The term "evolution" is usually associated with "survival-of-the most fittest" which means that those who are better adapted to certain environmental conditions will have a distinct advantage over those who are less well adapted. However it is only one of the many ways in which evolution can occur.
Another popular way to use the term "evolution" is to suggest that species are able to move from one stage to the next. This view of evolution can be described as anagenetic, or cladogenesis. This view is not supported by the definition of evolution that is scientifically accepted. Instead, the scientific theory of evolution concentrates on the changes that happen within populations over time and these changes are caused by mutations that produce genomic variation and natural selection.
Some scientists, such as the great Charles Darwin, advocated this view of evolution. Alfred Russel Wallace who developed the macroevolution theory believed this was the only way that higher forms of living could have evolved.
A theory must stand up to rigorous tests and evidence in order to be considered a theory. Evolution has stood the test of time and has been supported in numerous scientific disciplines ranging from biology to geology, chemistry to astronomy. In 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, particularly the relationship it has with religion.
What is the Theory of Evolution?
Evolution is the scientific explanation for the way living things change over time. It is based on a variety of well-established and observable facts such as the fact that more offspring are produced than could possibly survive in the long run; that individuals differ from each other in their physical characteristics (phenotype) and that various traits have different rates of survival and reproduction and can be passed down to future generations. These observations are supported by the growing body of evidence from molecular biology, palaeontology climatology, functional morphology and geology.
The theory of evolution through natural selection was conceived independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century to explain how organisms adapt to their physical and biological environments. It is the most widely accepted and tested theory in the field of science. Its predictions were confirmed by the fact that for instance, more complex organisms have less genetic mutations. The more successful an organism gets in terms of surviving and reproducing the more likely it will transmit its genes to future generations.
Some people are against evolution because they believe it implies that there is no reason to life. However, many scientists who are also religious such as the renowned 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 skilled evolutionary biologists have been involved in the development and testing the theory of evolution, including several highly respected evangelical Christian leaders. Many of these researchers contributed to the understanding a wide range phenomena, including genomics and phylogenetics as well as the formation and function of fossils.
The term "theory" is sometimes used incorrectly to mean a guess or speculation however it actually is a scientific hypothesis that has been rigorously evaluated and refined over time. Scientists test hypotheses through repeating the experiments or observations that led them to the conclusion. The theory of evolution has been repeatedly tested out and so have the 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 is the result of the natural selection of individuals that are better adapted to their environment. The more adapted individuals have higher chances of reproducing and survival. As more people survive and reproduce, their genes become more prevalent within the population. This process is sometimes described as "survival of the fittest."
According to evolution theory the causes of mutations that result in genomic variation are what triggers evolution. These mutations may occur at random or be influenced 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 and cause the allele to be spread across the population.
Over time, these shifts in allele frequencies could result in the creation of new species. The new species will then develop and evolve into new forms. This process is called macroevolution. The development of new species is typically due to changes in the environment, which make certain re sources available or creates new environmental problems. For instance, the rise of finches in the Galapagos Islands is a result of the abundance of food sources and the need to protect themselves from predators.
In a wider sense it is possible to define evolution as any change in the characteristics of living organisms over time. This change can be subtle, such as the development of new coloration or dramatic, like the development of an 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 long time, often millions of years. They differ on the importance of different factors that can accelerate or slow down the process. For instance the role of sexual selection, environmental pressures and mutation bias. Despite these differences, most scientists believe that evolution is happening and the evidence to prove this is overwhelming.
What is the Evidence of Evolution?
Throughout the years since Darwin's time, scientists have gathered evidence that supports his theory of evolution. This evidence is gathered from fossils which show the evolution of organisms over time. Similarities between living organisms as well as embryology, biogeography, and genetics are evidence.
The primary evidence of evolution is found in the evolutionary tree, which demonstrates how different species are related. Another evidence source is homologous structures, which have a similar structures in different species but serve different purposes, such as the wings of bats and birds. Evolution is evident in the way 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 evolution, which suggests that the species have common ancestors.
Vestigial structures are a different piece of evidence. These are parts of an organism which may have served some purpose in the past. For instance, the human appendix is a vestige of a once-used organ that served to digest food. These structures tend to shrink in size as they are no longer utilized, a process known as natural selection.
Scientists have also gathered evidence for evolution through observation and testing. The evidence for evolution can be grouped into six distinct categories: changes that can be observed at a smaller scale, biogeographic distributions, comparative anatomies, the fossil record and genetics. Each of these provides convincing evidence that evolution of life has taken place.
Many people have misconceptions about the theory of evolution. But, it's an established fact. It isn't only a theory, it is a powerful collection of decades of observations and data that has been tested and proven. Scientists continue to gather and analyze new data to better understand the arc of Earth's evolution, regardless of whether people believe in the theory of evolution or not. This information will aid scientists understand how to prevent future global catastrophes and also how to best use our planet's resources. This will allow us to better serve the needs of all the people living on the planet.