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What is Free Evolution? Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the emergence and development of new species. A variety of examples have been provided of this, including different kinds of stickleback fish that can be found in fresh or salt water and walking stick insect varieties that are attracted to specific host plants. These mostly reversible traits permutations are not able to explain fundamental changes to the basic body plan. Evolution by Natural Selection The development of the myriad of living creatures on Earth is a mystery that has fascinated scientists for centuries. Charles Darwin's natural selection theory is the best-established explanation. This happens when people who are more well-adapted are able to reproduce faster and longer than those who are less well-adapted. Over 에볼루션 무료체험 , a population of well-adapted individuals increases and eventually forms a whole new species. Natural selection is a cyclical process that involves the interaction of three factors that are inheritance, variation and reproduction. Mutation and sexual reproduction increase the genetic diversity of a species. Inheritance refers to the passing of a person's genetic characteristics to their offspring, which includes both dominant and recessive alleles. Reproduction is the process of producing viable, fertile offspring. This can be done through sexual or asexual methods. Natural selection only occurs when all of these factors are in harmony. If, for example the dominant gene allele allows an organism to reproduce and live longer than the recessive allele then the dominant allele is more common in a population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will go away. The process is self-reinforcing which means that an organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive feature. The higher the level of fitness an organism has as measured by its capacity to reproduce and endure, is the higher number of offspring it can produce. Individuals with favorable characteristics, such as having a long neck in Giraffes, or the bright white color patterns on male peacocks are more likely to others to survive and reproduce, which will eventually lead to them becoming the majority. Natural selection is only an element in the population and not on individuals. This is a major distinction from the Lamarckian theory of evolution which holds that animals acquire traits through use or lack of use. For instance, if a Giraffe's neck grows longer due to reaching out to catch prey, its offspring will inherit a larger neck. The differences in neck length between generations will continue until the giraffe's neck becomes too long to not breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles of the same gene are randomly distributed in a population. Eventually, one of them will reach fixation (become so widespread that it is unable to be removed through natural selection) and other alleles fall to lower frequency. In extreme cases this, it leads to one allele dominance. The other alleles are eliminated, and heterozygosity falls to zero. In a small population, this could lead to the complete elimination of the recessive allele. This is known as a bottleneck effect and it is typical of the kind of evolutionary process that takes place when a large number of people migrate to form a new group. A phenotypic 'bottleneck' can also occur when the survivors of a catastrophe such as an outbreak or mass hunt event are confined to an area of a limited size. The surviving individuals are likely to be homozygous for the dominant allele, meaning that they all have the same phenotype and therefore have the same fitness traits. This can be caused by war, earthquakes or even a plague. Regardless of the cause the genetically distinct population that is left might be prone to genetic drift. Walsh, Lewens and Ariew define drift as a deviation from the expected values due to differences in fitness. They give a famous instance of twins who are genetically identical and have identical phenotypes but one is struck by lightning and dies, whereas the other lives and reproduces. This kind of drift could be crucial in the evolution of an entire species. It is not the only method of evolution. Natural selection is the most common alternative, where mutations and migration keep the phenotypic diversity in a population. Stephens asserts that there is a significant distinction between treating drift as a force, or a cause and treating other causes of evolution, such as mutation, selection, and migration as forces or causes. Stephens claims that a causal process account of drift allows us to distinguish it from other forces, and this distinction is essential. He further argues that drift has a direction: that is, it tends to eliminate heterozygosity, and that it also has a magnitude, which is determined by population size. Evolution by Lamarckism Biology students in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is often referred to as “Lamarckism” and it states that simple organisms grow into more complex organisms via the inherited characteristics that result from the natural activities of an organism usage, use and disuse. Lamarckism is illustrated through a giraffe extending its neck to reach higher branches in the trees. This would cause the necks of giraffes that are longer to be passed onto their offspring who would then grow even taller. Lamarck Lamarck, a French zoologist, presented an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the conventional wisdom on organic transformation. According to him living things had evolved from inanimate matter via an escalating series of steps. Lamarck wasn't the first to propose this but he was thought of as the first to provide the subject a comprehensive and general treatment. The popular narrative is that Lamarckism was an opponent to Charles Darwin's theory of evolution by natural selection and that the two theories battled it out in the 19th century. Darwinism eventually triumphed and led to the development of what biologists now refer to as the Modern Synthesis. The theory argues that traits acquired through evolution can be inherited, and instead, it argues that organisms develop through the selective action of environmental factors, like natural selection. Although Lamarck supported the notion of inheritance by acquired characters and his contemporaries also paid lip-service to this notion however, it was not a major feature in any of their evolutionary theories. This is partly because it was never tested scientifically. It's been more than 200 years since Lamarck was born and in the age genomics, there is a large body of evidence supporting the possibility of inheritance of acquired traits. It is sometimes called “neo-Lamarckism” or more frequently, epigenetic inheritance. It is a form of evolution that is as valid as the more well-known Neo-Darwinian model. Evolution through the process of adaptation One of the most common misconceptions about evolution is its being driven by a fight for survival. In fact, this view is a misrepresentation of natural selection and ignores the other forces that are driving evolution. The fight for survival can be more accurately described as a struggle to survive in a certain environment. This may be a challenge for not just other living things as well as the physical environment itself. To understand how evolution works it is beneficial to understand what is adaptation. The term “adaptation” refers to any specific feature that allows an organism to live and reproduce within its environment. It can be a physical structure like fur or feathers. Or it can be a characteristic of behavior, like moving into the shade during hot weather, or coming out to avoid the cold at night. The ability of an organism to extract energy from its surroundings and interact with other organisms, as well as their physical environments is essential to its survival. The organism must possess the right genes to generate offspring, and it should be able to find sufficient food and other resources. The organism should also be able to reproduce itself at an amount that is appropriate for its specific niche. These elements, in conjunction with gene flow and mutation can result in changes in the ratio of alleles (different forms of a gene) in the gene pool of a population. This change in allele frequency can lead to the emergence of new traits, and eventually, new species as time passes. Many of the features we appreciate in animals and plants are adaptations. For instance lung or gills that extract oxygen from air feathers and fur for insulation, long legs to run away from predators and camouflage to conceal. To comprehend adaptation it is essential to discern between physiological and behavioral traits. Physiological traits like the thick fur and gills are physical characteristics. Behavior adaptations aren't like the tendency of animals to seek out companionship or to retreat into the shade during hot weather. It is important to keep in mind that lack of planning does not result in an adaptation. In fact, a failure to think about the consequences of a choice can render it unadaptable despite the fact that it might appear reasonable or even essential.