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What is Free Evolution? Free evolution is the notion that the natural processes of organisms can cause them to develop over time. This includes the evolution of new species as well as the transformation of the appearance of existing ones. A variety of examples have been provided of this, including various varieties of stickleback fish that can live in either salt or fresh water, and walking stick insect varieties that favor specific host plants. These reversible traits do not explain the fundamental changes in basic body plans. Evolution by Natural Selection Scientists have been fascinated by the development of all the living creatures that inhabit our planet for ages. The most well-known explanation is Charles Darwin's natural selection, a process that is triggered when more well-adapted individuals live longer and reproduce more successfully than those less well adapted. As time passes, the number of individuals who are well-adapted grows and eventually forms a new species. Natural selection is an ongoing process and involves the interaction of three factors that are: reproduction, variation and inheritance. Sexual reproduction and mutations increase the genetic diversity of the species. Inheritance refers the transmission of a person’s genetic traits, which include recessive and dominant genes and their offspring. Reproduction is the production of fertile, viable offspring, which includes both sexual and asexual methods. Natural selection can only occur when all these elements are in equilibrium. For instance when an allele that is dominant at a gene allows an organism to live and reproduce more often than the recessive allele, the dominant allele will be more common within the population. However, if the allele confers an unfavorable survival advantage or decreases fertility, it will disappear from the population. The process is self-reinforcing meaning that an organism that has an adaptive trait will survive and reproduce more quickly than those with a maladaptive trait. The more offspring an organism produces the better its fitness, which is measured by its capacity to reproduce itself and live. People with desirable traits, like the long neck of Giraffes, or the bright white patterns on male peacocks are more likely to others to live and reproduce and eventually lead to them becoming the majority. Natural selection is a factor in populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution, which states that animals acquire characteristics through use or neglect. If a giraffe expands its neck to reach prey and the neck grows longer, then its children will inherit this characteristic. The differences in neck length between generations will persist until the neck of the giraffe becomes too long that it can no longer breed with other giraffes. Evolution through Genetic Drift In the process of genetic drift, alleles within a gene can attain different frequencies within a population by chance events. Eventually, one of them will reach fixation (become so common that it is unable to be eliminated by natural selection), while other alleles fall to lower frequency. This can lead to a dominant allele in extreme. The other alleles are virtually eliminated and heterozygosity decreased to zero. In a small population it could lead to the total elimination of recessive allele. This is known as the bottleneck effect and is typical of an evolutionary process that occurs when a large number individuals migrate to form a population. A phenotypic bottleneck can also happen when the survivors of a catastrophe such as an epidemic or a massive hunting event, are concentrated in a limited area. The survivors will have an dominant allele, and will share the same phenotype. This could be caused by war, earthquakes, or even plagues. The genetically distinct population, if it is left, could be susceptible 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 for differences in fitness. They give a famous example of twins that are genetically identical, have identical phenotypes, and yet one is struck by lightning and dies, while the other lives and reproduces. This kind of drift could play a very important part in the evolution of an organism. But, it's not the only method to evolve. The main alternative is a process called natural selection, where the phenotypic variation of an individual is maintained through mutation and migration. Stephens asserts that there is a significant distinction between treating drift as a force or as a cause and considering other causes of evolution like mutation, selection and migration as causes or causes. Stephens claims that a causal process model of drift allows us to distinguish it from other forces, and this differentiation is crucial. He further argues that drift has a direction, i.e., it tends towards eliminating heterozygosity. It also has a size that is determined by the size of the population. Evolution through Lamarckism Students of biology in high school are frequently exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution, commonly referred to as “Lamarckism which means that simple organisms develop into more complex organisms taking on traits that result from an organism's use and disuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher branches in the trees. This process would cause giraffes to give their longer necks to their offspring, who would then become taller. Lamarck was a French zoologist and, in his inaugural lecture for his course on invertebrate zoology held at the Museum of Natural History in Paris on the 17th of May in 1802, he introduced an original idea that fundamentally challenged the conventional wisdom about organic transformation. According to Lamarck, living creatures evolved from inanimate matter by a series of gradual steps. Lamarck wasn't the first to suggest this however he was widely thought of as the first to offer the subject a thorough and general explanation. The most popular story is that Charles Darwin's theory of natural selection and Lamarckism were rivals in the 19th century. Darwinism ultimately prevailed and led to what biologists call the Modern Synthesis. The theory argues that acquired traits can be passed down and instead, it claims that organisms evolve through the influence of environment elements, like Natural Selection. Although Lamarck believed in the concept of inheritance through acquired characters, and his contemporaries also offered a few words about this idea, it was never a major feature in any of their evolutionary theories. This is largely due to the fact that it was never validated scientifically. It's been more than 200 years since Lamarck was born and in the age of genomics there is a huge body of evidence supporting the possibility of inheritance of acquired traits. This is referred to as “neo Lamarckism”, or more generally epigenetic inheritance. This is a version that is as reliable as the popular neodarwinian model. Evolution through adaptation One of the most popular misconceptions about evolution is its being driven by a struggle for survival. In fact, this view misrepresents natural selection and ignores the other forces that determine the rate of evolution. The fight for survival can be better described as a struggle to survive in a particular environment. This can include not just other organisms but also the physical environment. To understand how evolution works, it is helpful to understand what is adaptation. It refers to a specific feature that allows an organism to survive and reproduce in its environment. It can be a physical feature, such as feathers or fur. 무료 에볼루션 could also be a behavior trait such as moving into the shade during the heat, or escaping the cold at night. The survival of an organism is dependent on its ability to obtain energy from the environment and to interact with other living organisms and their physical surroundings. The organism must have the right genes to create offspring and be able find enough food and resources. The organism should be able to reproduce at the rate that is suitable for its niche. These elements, along with mutations and gene flow can result in an alteration in the ratio of different alleles within a population’s gene pool. As time passes, this shift in allele frequency can lead to the emergence of new traits and eventually new species. Many of the characteristics we appreciate in plants and animals are adaptations. For instance, lungs or gills that draw oxygen from air, fur and feathers as insulation long legs to run away from predators and camouflage for hiding. However, a proper understanding of adaptation requires attention to the distinction between physiological and behavioral traits. Physiological adaptations, such as thick fur or gills are physical traits, whereas behavioral adaptations, such as the tendency to seek out companions or to move into the shade in hot weather, are not. Additionally, it is important to note that a lack of thought is not a reason to make something an adaptation. Failure to consider the consequences of a decision, even if it appears to be rational, could make it unadaptive.