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What is Free Evolution? Free evolution is the idea that natural processes can cause organisms to develop over time. This includes the appearance and development of new species. A variety of examples have been provided of this, such as different kinds of stickleback fish that can be found in salt or fresh water, as well as walking stick insect varieties that favor specific host plants. These typically reversible traits do not explain the fundamental changes in the body's basic plans. Evolution by Natural Selection The development of the myriad of living creatures on Earth is a mystery that has fascinated scientists for decades. The most widely accepted explanation is Darwin's natural selection, which occurs when individuals that are better adapted survive and reproduce more successfully than those that are less well-adapted. As time passes, the number of well-adapted individuals becomes larger and eventually creates a new species. Natural selection is an ongoing process that is characterized by the interaction of three factors: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity of a species. Inheritance is the term used to describe the transmission of genetic traits, which include recessive and dominant genes, to their offspring. Reproduction is the production of fertile, viable offspring, which includes both asexual and sexual methods. All of these factors must be in balance for natural selection to occur. If, for instance, a dominant gene allele causes an organism reproduce and last longer than the recessive allele then the dominant allele is more prevalent in a group. But if the allele confers an unfavorable survival advantage or reduces fertility, it will disappear from the population. The process is self-reinforced, meaning that an organism that has a beneficial trait will survive and reproduce more than an individual with a maladaptive trait. The higher the level of fitness an organism has as measured by its capacity to reproduce and survive, is the more offspring it can produce. People with good characteristics, such as a long neck in the giraffe, or bright white patterns on male peacocks are more likely to others to survive and reproduce which eventually leads to them becoming the majority. Natural selection is an element in the population and not on individuals. This is an important distinction from the Lamarckian theory of evolution, which states that animals acquire characteristics through use or disuse. For example, if a giraffe's neck gets longer through stretching to reach prey its offspring will inherit a longer neck. The differences in neck size between generations will increase until the giraffe is no longer able to reproduce with other giraffes. Evolution through Genetic Drift In genetic drift, the alleles of a gene could reach different frequencies in a population through random events. At some point, one will attain fixation (become so widespread that it is unable to be removed through natural selection), while the other alleles drop to lower frequency. In extreme cases, this leads to one allele dominance. The other alleles are basically eliminated and heterozygosity has decreased to a minimum. In a small group this could result in the total elimination of recessive alleles. This is known as the bottleneck effect and is typical of the evolutionary process that occurs when a large number individuals migrate to form a population. A phenotypic bottleneck may also occur when the survivors of a disaster such as an outbreak or mass hunting event are concentrated in an area of a limited size. The survivors are likely to be homozygous for the dominant allele which means they will all have the same phenotype and consequently share the same fitness characteristics. This situation might be caused by a conflict, earthquake or even a disease. Regardless of the cause the genetically distinct population that remains could be prone to genetic drift. Walsh, Lewens and Ariew define drift as a deviation from the expected value due to differences in fitness. They cite the famous example of twins who are genetically identical and share the same phenotype, but one is struck by lightning and dies, but the other is able to reproduce. This kind of drift could be crucial in the evolution of a species. But, it's not the only method to evolve. The primary alternative is a process known as natural selection, where the phenotypic diversity of an individual is maintained through mutation and migration. Stephens claims that there is a significant distinction between treating drift as a force or a cause and considering other causes of evolution like mutation, selection, and migration as forces or causes. He argues that a causal process explanation of drift allows us to distinguish it from other forces, and that this distinction is crucial. He argues further that drift has direction, i.e., it tends towards eliminating heterozygosity. It also has a size which is determined by population size. Evolution through 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 commonly referred to as “Lamarckism” and it asserts that simple organisms evolve into more complex organisms via the inheritance of traits that are a result of the organism's natural actions usage, use and disuse. Lamarckism can be demonstrated by the giraffe's neck being extended to reach higher levels of leaves in the trees. This causes giraffes' longer necks to be passed onto their offspring who would then grow even taller. Lamarck Lamarck, a French zoologist, presented a revolutionary concept in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. In his view living things had evolved from inanimate matter via an escalating series of steps. Lamarck wasn't the only one to propose this however he was widely thought of as the first to provide the subject a comprehensive and general explanation. The most popular story is that Lamarckism became a rival to Charles Darwin's theory of evolution by natural selection, and both theories battled each other in the 19th century. Darwinism ultimately won, leading to what biologists call the Modern Synthesis. This theory denies acquired characteristics can be passed down and instead argues organisms evolve by the selective influence of environmental elements, like Natural Selection. Lamarck and his contemporaries supported the idea that acquired characters could be passed down to the next generation. However, this idea was never a central part of any of their evolutionary theories. This is largely due to the fact that it was never validated scientifically. However, it has been more than 200 years since Lamarck was born and in the age genomics there is a huge amount of evidence that supports the possibility of inheritance of acquired traits. This is sometimes referred to as “neo-Lamarckism” or, more frequently, epigenetic inheritance. This is a version that is just as valid as the popular neodarwinian model. Evolution through Adaptation One of the most popular misconceptions about evolution is that it is driven by a sort of struggle to survive. In reality, this notion is a misrepresentation of natural selection and ignores the other forces that are driving evolution. The fight for survival can be more effectively described as a struggle to survive within a specific environment, which could include not just other organisms, but also the physical environment. To understand how evolution functions it is important to consider what adaptation is. It is a feature that allows living organisms to live in its environment and reproduce. It can be a physical structure, like fur or feathers. It could also be a behavior trait, like moving towards shade during hot weather, or escaping the cold at night. The survival of an organism depends on its ability to obtain energy from the surrounding environment and interact with other living organisms and their physical surroundings. 에볼루션 슬롯 should possess the right genes to create offspring and be able find sufficient food and resources. The organism should also be able reproduce at an amount that is appropriate for its specific niche. These factors, together with mutation and gene flow result in a change in the proportion of alleles (different varieties of a particular gene) in the population's gene pool. Over time, this change in allele frequencies could lead to the emergence of new traits, and eventually new species. A lot of the traits we admire in animals and plants are adaptations, such as the lungs or gills that extract oxygen from the air, fur or feathers to protect themselves, long legs for running away from predators and camouflage to hide. To comprehend adaptation it is essential to differentiate between physiological and behavioral characteristics. Physiological adaptations, such as thick fur or gills are physical characteristics, whereas behavioral adaptations, such as the tendency to seek out companions or to retreat to the shade during hot weather, are not. It is important to keep in mind that lack of planning does not result in an adaptation. Failure to consider the implications of a choice even if it seems to be rational, could make it unadaptive.