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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 development of new species as well as the alteration of the appearance of existing ones. This is evident in numerous examples of stickleback fish species that can thrive in saltwater or fresh water and walking stick insect species that are apprehensive about particular host plants. These are mostly reversible traits, however, cannot be the reason for fundamental changes in body plans. Evolution by Natural Selection Scientists have been fascinated by the evolution of all the living creatures that inhabit our planet for centuries. Charles Darwin's natural selection theory is the most well-known explanation. This process occurs when those who are better adapted are able to reproduce faster and longer than those who are less well-adapted. As time passes, the number of well-adapted individuals grows and eventually develops into an entirely new species. Natural selection is an ongoing process and involves the interaction of three factors: variation, reproduction and inheritance. Variation is caused by mutations and sexual reproduction both of which enhance the genetic diversity of a species. Inheritance is the transfer of a person's genetic traits to his or her offspring, which includes both recessive and dominant alleles. Reproduction is the process of producing fertile, viable offspring. This can be achieved by both asexual or sexual methods. Natural selection can only occur when all the factors are in equilibrium. If, for instance, a dominant gene allele causes an organism reproduce and live longer than the recessive allele then the dominant allele will become more prevalent in a population. If the allele confers a negative advantage to survival or reduces the fertility of the population, it will disappear. The process is self-reinforced, meaning that a species with a beneficial trait will survive and reproduce more than one with an inadaptive trait. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the greater number of offspring it can produce. People with desirable traits, such as a longer neck in giraffes, or bright white color patterns in male peacocks are more likely be able to survive and create offspring, which means they will become the majority of the population in the future. Natural selection is an aspect of populations and not on individuals. 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 children will inherit this characteristic. The differences in neck size between generations will continue to increase until the giraffe is unable to breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when the alleles of the same gene are randomly distributed within a population. At some point, only one of them will be fixed (become common enough to no longer be eliminated through natural selection) and the other alleles will drop in frequency. In the extreme it can lead to a single 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 scenario is called the bottleneck effect and is typical of an evolution process that occurs when the number of individuals migrate to form a group. A phenotypic 'bottleneck' can also occur when survivors of a disaster like an outbreak or mass hunt event are confined to an area of a limited size. The survivors will have an dominant allele, and will share the same phenotype. This could be caused by a war, an earthquake, or even a plague. The genetically distinct population, if left susceptible to genetic drift. Walsh, Lewens, and Ariew use a “purely outcome-oriented” definition of drift as any departure from expected values for differences in fitness. They give a famous instance of twins who are genetically identical, share identical phenotypes but one is struck by lightening and dies while the other lives and reproduces. This kind of drift could be vital to the evolution of a species. 에볼루션 카지노 사이트 isn't the only method of evolution. Natural selection is the most common alternative, where mutations and migration keep phenotypic diversity within a population. Stephens claims that there is a vast distinction between treating drift as an actual cause or force, and treating other causes like migration and selection as forces and causes. Stephens claims that a causal process model of drift allows us to separate it from other forces, and this distinction is essential. He further argues that drift has a direction: that is, it tends to eliminate heterozygosity. It also has a size, which is determined by the size of population. Evolution through Lamarckism In 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 states that simple organisms develop into more complex organisms via the inheritance of characteristics that result from an organism's natural activities usage, use and disuse. Lamarckism is illustrated through the giraffe's neck being extended to reach higher levels of leaves in the trees. This could cause giraffes to pass on their longer necks to their offspring, which then grow even taller. 에볼루션코리아 was a French zoologist and, in his lecture to begin his course on invertebrate Zoology at the Museum of Natural History in Paris on 17 May 1802, he introduced an innovative concept that completely challenged previous thinking about organic transformation. In his view living things evolved from inanimate matter via the gradual progression of events. Lamarck was not the first to suggest that this might be the case, but he is widely seen as having given the subject its first general and thorough treatment. The most popular story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were rivals in the 19th century. Darwinism eventually triumphed and led to the development of what biologists refer to as the Modern Synthesis. This theory denies that acquired characteristics can be acquired through inheritance and instead argues that organisms evolve by the symbiosis of environmental factors, like natural selection. While Lamarck endorsed the idea of inheritance by acquired characters and his contemporaries paid lip-service to this notion, it was never an integral part of any of their evolutionary theorizing. This is largely due to the fact that it was never validated scientifically. It's been more than 200 years since the birth of Lamarck and in the field of genomics, there is an increasing body of evidence that supports the heritability acquired characteristics. This is often referred to as “neo-Lamarckism” or, more often epigenetic inheritance. This is a version that is just as valid as the popular Neodarwinian model. Evolution through Adaptation One of the most common misconceptions about evolution is being driven by a struggle for survival. In reality, this notion is inaccurate and overlooks the other forces that determine the rate of evolution. The fight for survival can be better described as a fight to survive in a certain environment. This may be a challenge for not just other living things, but also the physical environment itself. To understand how evolution works it is beneficial to think about what adaptation is. It is a feature that allows living organisms to live in its environment and reproduce. It could be a physiological feature, like feathers or fur, or a behavioral trait such as a tendency to move into the shade in the heat or leaving at night to avoid cold. The survival of an organism depends on its ability to draw energy from the environment and interact with other organisms and their physical environments. The organism needs to have the right genes to produce offspring, and it must be able to locate sufficient food and other resources. The organism must also be able to reproduce at the rate that is suitable for its specific niche. These elements, along with gene flow and mutations, can lead to a shift in the proportion of different alleles in a population’s gene pool. The change in frequency of alleles could lead to the development of new traits, and eventually new species in the course of time. Many of the features we appreciate in animals and plants are adaptations. For instance lung or gills that extract oxygen from air, fur and feathers as insulation, long legs to run away from predators and camouflage to conceal. To understand adaptation it is crucial to distinguish between behavioral and physiological traits. Physiological adaptations, like thick fur or gills are physical characteristics, whereas behavioral adaptations, such as the tendency to seek out companions or to move to the shade during hot weather, aren't. It is also important to remember that a lack of planning does not result in an adaptation. In fact, failing to consider the consequences of a choice can render it unadaptive, despite the fact that it may appear to be sensible or even necessary.