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What is Free Evolution? Free evolution is the notion that the natural processes that organisms go through can lead them to evolve over time. This includes the emergence and development of new species. This has been proven by numerous examples of stickleback fish species that can live in saltwater or fresh water and walking stick insect varieties that have a preference for particular host plants. These mostly reversible trait permutations can't, however, explain fundamental changes in basic body plans. Evolution by Natural Selection Scientists have been fascinated by the evolution of all the living organisms that inhabit our planet for ages. The best-established explanation is Charles Darwin's natural selection process, an evolutionary process that is triggered when more well-adapted individuals live longer and reproduce more effectively than those that are less well adapted. Over time, the population of well-adapted individuals grows and eventually creates an entirely new species. Natural selection is a process that is cyclical and involves the interaction of 3 factors including reproduction, variation and inheritance. Mutation and sexual reproduction increase the genetic diversity of a species. 에볼루션 게이밍 refers to the transmission of genetic characteristics, which includes both dominant and recessive genes, to their offspring. Reproduction is the process of producing viable, fertile offspring. This can be achieved by both asexual or sexual methods. All of these elements must be in harmony to allow natural selection to take place. For example, if the dominant allele of the gene allows an organism to live and reproduce more often than the recessive allele, the dominant allele will be more prominent within the population. If the allele confers a negative advantage to survival or reduces the fertility of the population, it will be eliminated. The process is self-reinforcing, meaning that an organism with a beneficial characteristic is more likely to survive and reproduce than one with an inadaptive characteristic. The more offspring that an organism has, the greater its fitness that is determined by its ability to reproduce itself and live. People with desirable characteristics, such as having a long neck in the giraffe, or bright white color patterns on male peacocks, are more likely than others to survive and reproduce which eventually leads to them becoming the majority. Natural selection is only a force for populations, not individual organisms. This is a significant distinction from the Lamarckian theory of evolution, which claims that animals acquire characteristics by use or inactivity. If a giraffe stretches its neck to reach prey and its neck gets longer, then the offspring will inherit this characteristic. The difference in neck length between generations will persist until the neck of the giraffe becomes so long that it can not breed with other giraffes. Evolution by Genetic Drift In the process of genetic drift, alleles within a gene can reach different frequencies within a population due to random events. At some point, one will reach fixation (become so common that it can no longer be removed through natural selection), while the other alleles drop to lower frequencies. In the extreme, this leads to a single allele dominance. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small number of people, this could lead to the complete elimination of recessive allele. This is known as the bottleneck effect and is typical of an evolution process that occurs when an enormous number of individuals move to form a population. A phenotypic bottleneck can also occur when the survivors of a disaster, such as an epidemic or mass hunting event, are condensed into a small area. The survivors will have a dominant allele and thus will have the same phenotype. This can be caused by earthquakes, war or even a plague. The genetically distinct population, if it remains, could be susceptible to genetic drift. Walsh Lewens, Walsh, and Ariew define drift as a departure from the expected values due to differences in fitness. They give the famous example of twins that are genetically identical and share the same phenotype. However, one is struck by lightning and dies, but the other continues to reproduce. This type of drift is very important in the evolution of a species. It's not the only method for evolution. The main alternative is a process called natural selection, in which phenotypic variation in a population is maintained by mutation and migration. Stephens asserts that there is a significant difference between treating drift like an actual cause or force, and treating other causes such as selection mutation and migration as forces and causes. He argues that a causal-process explanation of drift lets us differentiate it from other forces, and this differentiation is crucial. He also argues that drift has both a direction, i.e., it tends to reduce heterozygosity. It also has a size, that is determined by the size of the population. Evolution by Lamarckism When high school students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution is often called “Lamarckism” and it states that simple organisms grow into more complex organisms by the inherited characteristics that result from the organism's natural actions, use and disuse. Lamarckism can be illustrated by a giraffe extending its neck to reach higher leaves in the trees. This would cause the longer necks of giraffes to be passed on to their offspring who would then grow even taller. Lamarck Lamarck, a French Zoologist from France, presented an innovative idea in his opening lecture at the Museum of Natural History of Paris. He challenged the traditional thinking about organic transformation. In his opinion, living things had evolved from inanimate matter via the gradual progression of events. Lamarck was not the only one to suggest that this could be the case but he is widely seen as being the one who gave the subject its first broad and comprehensive treatment. The dominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism fought during the 19th century. Darwinism eventually prevailed which led to what biologists refer to as the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead, it claims that organisms evolve through the selective action of environment factors, such as Natural Selection. Lamarck and his contemporaries supported the notion that acquired characters could be passed down to the next generation. However, this notion was never a central part of any of their theories about evolution. This is partly due to the fact that it was never tested scientifically. However, it has been more than 200 years since Lamarck was born and in the age of genomics, there is a large amount of evidence that supports the heritability 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 popular Neo-Darwinian model. Evolution through the process of adaptation One of the most common misconceptions about evolution is being driven by a struggle for survival. This view is inaccurate and overlooks the other forces that determine the rate of evolution. The struggle for existence is better described as a fight to survive in a certain environment. This may include not only other organisms as well as the physical environment itself. To understand how evolution works, it is helpful to think about what adaptation is. The term “adaptation” refers to any specific feature that allows an organism to live and reproduce within its environment. It could be a physical structure like fur or feathers. Or it can be a trait of behavior that allows you to move to the shade during the heat, or coming out to avoid the cold at night. The survival of an organism depends on its ability to extract energy from the surrounding environment and interact with other organisms and their physical environments. The organism must have the right genes for producing offspring, and be able to find enough food and resources. The organism should be able to reproduce itself at the rate that is suitable for its particular niche. These elements, in conjunction with gene flow and mutation result in changes in the ratio of alleles (different types of a gene) in the population's gene pool. Over time, this change in allele frequencies could result in the development of new traits and eventually new species. Many of the characteristics we admire in animals and plants are adaptations, like the lungs or gills that extract oxygen from the air, feathers or fur to protect themselves and long legs for running away from predators and camouflage to hide. To comprehend adaptation, it is important to discern between physiological and behavioral traits. Physiological adaptations, such as thick fur or gills are physical characteristics, whereas behavioral adaptations, such as the desire to find companions or to retreat to the shade during hot weather, are not. In addition it is important to note that a lack of forethought is not a reason to make something an adaptation. Inability to think about the consequences of a decision, even if it appears to be rational, may make it unadaptive.