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What is Free Evolution? Free evolution is the idea that natural processes can lead to the development of organisms over time. This includes the emergence and development of new species. This is evident in many examples of stickleback fish species that can live in fresh or saltwater and walking stick insect types that prefer specific host plants. These reversible traits do not explain the fundamental changes in the body's basic plans. Evolution through Natural Selection The development of the myriad living organisms on Earth is a mystery that has fascinated scientists for centuries. The most well-known explanation is Darwin's natural selection process, which occurs when better-adapted individuals survive and reproduce more successfully than those that are less well adapted. Over time, the population of well-adapted individuals grows and eventually develops into an entirely new species. Natural selection is an ongoing process that is characterized by the interaction of three factors including inheritance, variation, and reproduction. Variation is caused by mutation and sexual reproduction both of which increase the genetic diversity within the species. Inheritance refers to the passing of a person's genetic traits to their offspring which includes both dominant and recessive alleles. Reproduction is the generation of fertile, viable offspring which includes both asexual and sexual methods. Natural selection only occurs when all the factors are in balance. For instance the case where the dominant allele of a gene can cause an organism to live and reproduce more frequently than the recessive allele, the dominant allele will become more prominent in the population. However, if the allele confers an unfavorable survival advantage or reduces fertility, it will disappear from the population. This process is self-reinforcing meaning that an organism with a beneficial characteristic will survive and reproduce more than one with an inadaptive characteristic. The more fit an organism is as measured by its capacity to reproduce and survive, is the more offspring it can produce. People with good traits, like a longer neck in giraffes, or bright white colors in male peacocks are more likely to survive and produce offspring, which means they will make up the majority of the population in the future. Natural selection is a factor in populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution which holds that animals acquire traits due to the use or absence of use. If a giraffe stretches its neck to catch prey and its neck gets larger, then its children will inherit this characteristic. The difference in neck size between generations will increase until the giraffe is unable to breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles of a gene are randomly distributed in a group. Eventually, only one will be fixed (become common enough that it can no longer be eliminated through natural selection) and the other alleles diminish in frequency. This could lead to a dominant allele in the extreme. The other alleles have been essentially eliminated and heterozygosity has decreased to a minimum. In a small population it could result in the complete elimination of recessive gene. This scenario is called the bottleneck effect and is typical of an evolutionary process that occurs when the number of individuals migrate to form a population. A phenotypic bottleneck can also happen when the survivors of a disaster such as an epidemic or a mass hunting event, are condensed within a narrow area. The survivors will carry an dominant allele, and will share the same phenotype. This could be caused by earthquakes, war or even a plague. Whatever 에볼루션 바카라사이트 that remains could be prone to genetic drift. Walsh, Lewens, and Ariew use Lewens, Walsh, and Ariew use a “purely outcome-oriented” definition of drift as any deviation from the expected values of variations in fitness. They provide the famous case of twins who are both genetically identical and have exactly the same phenotype. However one is struck by lightning and dies, whereas the other lives to reproduce. This kind of drift can be crucial in the evolution of a species. However, it's not the only method to progress. Natural selection is the most common alternative, in which mutations and migration keep the phenotypic diversity in a population. Stephens asserts that there is a huge difference between treating the phenomenon of drift as an actual cause or force, and treating other causes like migration and selection as causes and forces. Stephens claims that a causal process model of drift allows us to distinguish it from other forces, and this distinction is essential. He argues further that drift has an orientation, i.e., it tends towards eliminating heterozygosity. It also has a size that is determined by population size. Evolution by Lamarckism Students of biology in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution, also referred to as “Lamarckism”, states that simple organisms develop into more complex organisms by adopting traits that result from the organism's use and misuse. Lamarckism is usually illustrated with the image of a giraffe extending its neck further to reach the higher branches in the trees. This could cause giraffes to give their longer necks to their offspring, who then get taller. Lamarck Lamarck, a French Zoologist from France, presented a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged conventional wisdom on organic transformation. According Lamarck, living organisms evolved from inanimate materials by a series of gradual steps. Lamarck was not the only one to suggest that this might be the case, but his reputation is widely regarded as giving the subject his first comprehensive and thorough treatment. The prevailing story is that Lamarckism became an opponent to Charles Darwin's theory of evolutionary natural selection and both theories battled out in the 19th century. Darwinism eventually prevailed and led to the creation of what biologists now refer to as the Modern Synthesis. The theory argues that acquired traits can be passed down through generations and instead argues that organisms evolve through the selective action of environment factors, such as Natural Selection. Lamarck and his contemporaries supported the idea that acquired characters could be passed down to the next generation. However, this concept was never a central part of any of their theories on evolution. This is partly because it was never scientifically validated. But it is now more than 200 years since Lamarck was born and, in the age of genomics, there is a large amount of evidence to support the heritability of acquired traits. This is often referred to as “neo-Lamarckism” or more frequently, epigenetic inheritance. It is a version of evolution that is just as relevant as the more popular neo-Darwinian model. Evolution by adaptation One of the most widespread misconceptions about evolution is that it is driven by a sort of struggle to survive. This view is inaccurate and overlooks other forces that drive evolution. The fight for survival can be more accurately described as a struggle to survive within a specific environment, which can involve not only other organisms, but also the physical environment itself. To understand how evolution operates, it is helpful to think about what adaptation is. It refers to a specific characteristic that allows an organism to survive and reproduce in its environment. It could be a physical structure, like fur or feathers. It could also be a trait of behavior that allows you to move to the shade during hot weather or escaping the cold at night. The survival of an organism is dependent on its ability to draw energy from the environment and interact with other organisms and their physical environments. The organism should possess the right genes for producing offspring and be able find sufficient food and resources. The organism should also be able to reproduce itself at an amount that is appropriate for its specific niche. These factors, together with gene flow and mutation result in an alteration in the percentage of alleles (different varieties of a particular gene) in a population's gene pool. This change in allele frequency could lead to the development of novel 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 draw oxygen from air feathers and fur as insulation long legs to run away from predators and camouflage to conceal. To comprehend adaptation, it is important to discern between physiological and behavioral characteristics. Physiological adaptations like thick fur or gills are physical traits, while behavioral adaptations, such as the desire to find friends or to move into the shade in hot weather, aren't. It is important to keep in mind that insufficient planning does not cause an adaptation. Failure to consider the implications of a choice even if it appears to be rational, could make it inflexible.