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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. 에볼루션 코리아 includes the appearance and development of new species. Numerous examples have been offered of this, including different kinds of stickleback fish that can live in either salt or fresh water, as well as walking stick insect varieties that are attracted to particular host plants. These mostly reversible trait permutations, however, cannot explain fundamental changes in basic body plans. Evolution by Natural Selection Scientists have been fascinated by the evolution of all living organisms that inhabit our planet for many centuries. Charles Darwin's natural selection theory is the best-established explanation. This process occurs when people who are more well-adapted survive and reproduce more than those who are less well-adapted. As time passes, the number of well-adapted individuals grows and eventually creates a new species. Natural selection is a cyclical process that is characterized by the interaction of three factors that are inheritance, variation and reproduction. Sexual reproduction and mutations increase genetic diversity in the species. Inheritance refers to the transmission of genetic traits, including recessive and dominant genes to their offspring. Reproduction is the process of creating viable, fertile offspring. This can be accomplished by both asexual or sexual methods. Natural selection is only possible when all these elements are in harmony. If, for instance the dominant gene allele allows an organism to reproduce and survive more than the recessive gene then the dominant allele is more prevalent in a population. However, if the allele confers a disadvantage in survival or reduces fertility, it will disappear from the population. The process is self-reinforced, which means that an organism that has a beneficial trait is more likely to survive and reproduce than an individual with an inadaptive trait. The more offspring an organism can produce, the greater its fitness, which is measured by its ability to reproduce itself and live. People with desirable traits, like having a longer neck in giraffes or bright white patterns of color in male peacocks, are more likely to survive and have offspring, so they will eventually make up the majority of the population in the future. Natural selection is only a force for populations, not individuals. This is a major distinction from the Lamarckian theory of evolution which argues that animals acquire traits by use or inactivity. For example, if a animal's neck is lengthened by reaching out to catch prey, its offspring will inherit a larger neck. The length difference between generations will continue until the giraffe's neck becomes too long to not breed with other giraffes. Evolution through Genetic Drift Genetic drift occurs when alleles of a gene are randomly distributed in a population. Eventually, one of them will attain fixation (become so widespread that it cannot be removed by natural selection), while the other alleles drop to lower frequencies. In extreme cases it can lead to a single allele dominance. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small population this could lead to the complete elimination of recessive gene. This scenario is called the bottleneck effect. It is typical of an evolution process that occurs when a large number individuals migrate to form a population. A phenotypic bottleneck may also occur when the survivors of a catastrophe such as an outbreak or mass hunting incident are concentrated in a small area. The survivors will share an allele that is dominant and will have the same phenotype. This can be caused by war, earthquakes or even a plague. The genetically distinct population, if it remains susceptible to genetic drift. Walsh, Lewens and Ariew define drift as a departure from the expected values due to differences in fitness. They give a famous instance of twins who are genetically identical, have identical phenotypes, and yet 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 for evolution. The main alternative is a process called natural selection, where the phenotypic variation of the population is maintained through mutation and migration. Stephens claims that there is a significant distinction between treating drift as a force, or an underlying cause, and treating other causes of evolution like selection, mutation and migration as causes or causes. Stephens claims that a causal process model of drift allows us to separate it from other forces and this distinction is essential. 에볼루션 바카라 무료체험 argues that drift is a directional force: that is it tends to reduce heterozygosity, and that it also has a magnitude, that is determined by the size of the population. Evolution through Lamarckism When students in high school study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution, commonly called “Lamarckism, states that simple organisms develop into more complex organisms by inheriting characteristics that result from the organism's use and misuse. Lamarckism is illustrated through a giraffe extending its neck to reach higher leaves in the trees. This could cause giraffes' longer necks to be passed on to their offspring who would grow taller. Lamarck, a French Zoologist, introduced an idea that was revolutionary 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 Lamarck, living creatures evolved from inanimate matter by a series of gradual steps. Lamarck was not the first to suggest that this could be the case but he is widely seen as being the one who gave the subject his first comprehensive and comprehensive analysis. The predominant story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were competing during the 19th century. Darwinism eventually prevailed and led to what biologists refer to as the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead argues organisms evolve by the selective action of environment factors, including Natural Selection. Although Lamarck endorsed the idea of inheritance through acquired characters, and his contemporaries also spoke of this idea but it was not an integral part of any of their evolutionary theorizing. This is due to the fact that it was never tested scientifically. But it is now more than 200 years since Lamarck was born and in the age of genomics there is a huge amount of evidence that supports the heritability of acquired characteristics. This is sometimes called “neo-Lamarckism” or, more commonly, epigenetic inheritance. It is a version of evolution that is as relevant as the more popular neo-Darwinian model. Evolution through the process of adaptation One of the most commonly-held misconceptions about evolution is that it is being driven by a fight for survival. This view is inaccurate and overlooks the other forces that drive evolution. The struggle for survival is more accurately described as a struggle to survive within a specific environment, which may include not just other organisms but as well the physical environment. Understanding adaptation is important to understand evolution. The term “adaptation” refers to any specific characteristic that allows an organism to survive and reproduce in its environment. It could be a physical feature, like fur or feathers. It could also be a trait of behavior, like moving into the shade during hot weather, or escaping the cold at night. The capacity of an organism to extract energy from its surroundings and interact with other organisms as well as their physical environment, is crucial to its survival. The organism must possess the right genes to create offspring, and be able to find sufficient food and resources. Furthermore, the organism needs to be capable of reproducing itself at an optimal rate within its environmental niche. These factors, in conjunction with gene flow and mutations, can lead to changes in the proportion of different alleles in a population’s gene pool. As time passes, this shift in allele frequencies could result in the emergence of new traits and ultimately new species. Many of the characteristics we appreciate in animals and plants are adaptations. For example, lungs or gills that extract oxygen from air feathers and fur for insulation and long legs to get away from predators and camouflage for hiding. To comprehend adaptation it is crucial to discern between physiological and behavioral characteristics. Physiological adaptations like thick fur or gills, are physical traits, while behavioral adaptations, such as the tendency to search for companions or to retreat to the shade during hot weather, aren't. It is important to keep in mind that insufficient planning does not make an adaptation. Inability to think about the implications of a choice even if it appears to be logical, can cause it to be unadaptive.