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What is Free Evolution? Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the appearance and development of new species. This has been demonstrated by numerous examples such as the stickleback fish species that can thrive in saltwater or fresh water and walking stick insect species that are apprehensive about particular host plants. These mostly reversible traits permutations cannot explain fundamental changes to basic body plans. Evolution through Natural Selection The development of the myriad of living creatures on Earth is an enigma that has fascinated scientists for many centuries. Charles Darwin's natural selection theory is the best-established explanation. This process occurs when those who are better adapted survive and reproduce more than those who are less well-adapted. Over time, a community of well-adapted individuals expands and eventually becomes a new species. Natural selection is an ongoing process that involves the interaction of three factors including inheritance, variation, and reproduction. Variation is caused by mutations and sexual reproduction, both of which increase the genetic diversity within an animal species. Inheritance is the transfer of a person's genetic characteristics to his or her offspring which includes both recessive and dominant 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 equilibrium. For instance the case where an allele that is dominant at the gene allows an organism to live and reproduce more frequently than the recessive one, the dominant allele will become more prevalent in the population. However, if the allele confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. The process is self-reinforcing, which means that an organism that has an adaptive trait will survive and reproduce more quickly than one with a maladaptive characteristic. The more fit an organism is, measured by its ability reproduce and survive, is the greater number of offspring it can produce. People with good traits, like longer necks in giraffes and bright white color patterns in male peacocks are more likely to survive and produce offspring, and thus will become the majority of the population over time. Natural selection is only a force for populations, not on individuals. This is a significant distinction from the Lamarckian theory of evolution, which argues that animals acquire characteristics through use or neglect. If a giraffe stretches its neck to reach prey and the neck grows longer, then its offspring will inherit this trait. The difference in neck size between generations will increase until the giraffe is no longer able to reproduce with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles from one gene are distributed randomly in a population. In the end, one will reach fixation (become so common that it cannot be eliminated through natural selection), while the other alleles drop to lower frequency. In the extreme it can lead to dominance of a single allele. The other alleles have been essentially eliminated and heterozygosity has been reduced to a minimum. In a small group it could result in the complete elimination of recessive gene. Such a scenario would be known as a bottleneck effect and it is typical of evolutionary process that takes place when a lot of individuals move to form a new group. A phenotypic bottleneck may also occur when the survivors of a catastrophe such as an outbreak or mass hunting incident are concentrated in an area of a limited size. The remaining individuals are likely to be homozygous for the dominant allele which means that they will all share the same phenotype and will consequently share the same fitness characteristics. This could be the result of a war, earthquake or even a disease. Regardless of the cause the genetically distinct group that remains is prone to genetic drift. Walsh Lewens and Ariew employ Lewens, Walsh and Ariew employ a “purely outcome-oriented” definition of drift as any deviation from expected values for different fitness levels. They provide the famous case of twins that are genetically identical and have exactly the same phenotype, but one is struck by lightning and dies, while the other continues to reproduce. This kind of drift could play a crucial role in the evolution of an organism. It's not the only method of evolution. Natural selection is the primary alternative, in which mutations and migration maintain the phenotypic diversity in a population. Stephens claims that there is a significant difference between treating the phenomenon of drift as an agent or cause and treating other causes such as selection mutation and migration as forces and causes. He claims that a causal-process explanation of drift lets us distinguish it from other forces and that this distinction is crucial. He also claims that drift has a direction, that is it tends to reduce heterozygosity, and that it also has a magnitude, which is determined by the size of the population. Evolution through Lamarckism Biology students in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution, often referred to as “Lamarckism which means that simple organisms evolve into more complex organisms adopting traits that result from an organism's use and disuse. Lamarckism is typically illustrated with a picture of a giraffe extending its neck longer to reach higher up in the trees. This would cause giraffes to pass on their longer necks to offspring, which then get taller. Lamarck, a French Zoologist from France, 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 through a series of gradual steps. Lamarck wasn't the first to propose this, but he was widely regarded as the first to offer the subject a thorough and general explanation. The dominant story is that Charles Darwin's theory on natural selection and Lamarckism were competing in the 19th century. Darwinism eventually prevailed and led to the creation of what biologists today call the Modern Synthesis. The theory argues the possibility that acquired traits can be inherited and instead argues that organisms evolve through the action of environmental factors, like natural selection. Lamarck and his contemporaries believed in the notion that acquired characters could be passed down to future generations. However, this idea was never a major part of any of their theories on evolution. This is largely due to the fact that it was never tested scientifically. It's been more than 200 years since Lamarck was born and, in the age of genomics there is a vast body of evidence supporting the possibility of inheritance of acquired traits. This is often called “neo-Lamarckism” or, more often epigenetic inheritance. This is a model that is just as valid as the popular neodarwinian model. Evolution by adaptation One of the most common misconceptions about evolution is that it is being driven by a struggle to survive. 에볼루션 게이밍 is not true and overlooks other forces that drive evolution. The fight for survival can be more accurately described as a struggle to survive in a specific environment. This may be a challenge for not just other living things as well as the physical environment. To understand how evolution operates, it is helpful to think about what adaptation is. It is a feature that allows living organisms to live in its environment and reproduce. It can be a physiological feature, such as feathers or fur or a behavioral characteristic like moving into shade in the heat or leaving at night to avoid the cold. The ability of an organism to extract energy from its surroundings and interact with other organisms as well as their physical environments is essential to its survival. The organism must possess the right genes to produce offspring and to be able to access sufficient food and resources. Moreover, the organism must be capable of reproducing itself at an optimal rate within its niche. These elements, along with mutations and gene flow can cause changes in the proportion of different alleles within the population's gene pool. The change in frequency of alleles can lead to the emergence of new traits, and eventually, new species over time. Many of the features that we admire about animals and plants are adaptations, for example, lungs or gills to extract oxygen from the air, fur or feathers to protect themselves and long legs for running away from predators, and camouflage to hide. However, a proper understanding of adaptation requires paying attention to the distinction between the physiological and behavioral traits. Physiological adaptations like the thick fur or gills are physical traits, while behavioral adaptations, such as the tendency to search for friends or to move into the shade in hot weather, are not. It is also important to keep in mind that insufficient planning does not make an adaptation. Inability to think about the consequences of a decision, even if it appears to be rational, could make it inflexible.