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What is Free Evolution? Free evolution is the notion that the natural processes that organisms go through can lead them to evolve over time. This includes the creation of new species and the transformation of the appearance of existing ones. Many examples have been given of this, such as different varieties of fish called sticklebacks that can live in either salt or fresh water, and walking stick insect varieties that favor particular host plants. These are mostly reversible traits, however, cannot explain fundamental changes in basic body plans. Evolution by Natural Selection The development of the myriad living organisms on Earth is an enigma that has intrigued scientists for centuries. Charles Darwin's natural selection is the most well-known explanation. This is because people who are more well-adapted survive and reproduce more than those who are less well-adapted. Over time, the population of individuals who are well-adapted grows and eventually forms a new species. Natural selection is a process that is cyclical 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 to the transmission of a person's genetic characteristics, which includes both dominant and recessive genes and their offspring. Reproduction is the process of producing fertile, viable offspring which includes both sexual and asexual methods. Natural selection only occurs when all these elements are in equilibrium. If, for instance, a dominant gene allele causes an organism reproduce and survive more than the recessive gene allele The dominant allele is more prevalent in a group. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will disappear. The process is self-reinforced, meaning that an organism with a beneficial characteristic will survive and reproduce more than an individual with an unadaptive characteristic. The greater an organism's fitness as measured by its capacity to reproduce and endure, is the higher number of offspring it will produce. Individuals with favorable traits, like a long neck in giraffes, or bright white color patterns on male peacocks are more likely to others to live and reproduce and eventually lead to them becoming the majority. Natural selection is only an element in the population and not on individuals. This is an important distinction from the Lamarckian theory of evolution, which argues that animals acquire characteristics through use or disuse. For instance, if the giraffe's neck gets longer through stretching to reach for prey, its offspring will inherit a longer neck. The difference in neck size between generations will continue to increase until the giraffe is no longer able to breed with other giraffes. Evolution by Genetic Drift In genetic drift, alleles of a gene could be at different frequencies in a group due to random events. Eventually, only one will be fixed (become common enough that it can no longer be eliminated through natural selection) and the other alleles decrease in frequency. In the extreme it can lead to one allele dominance. The other alleles have been essentially eliminated and heterozygosity has been reduced to a minimum. In a small group it could lead to the complete elimination of recessive allele. This scenario is called a bottleneck effect, and it is typical of the kind of evolutionary process that takes place when a lot of individuals migrate to form a new population. A phenotypic bottleneck could occur when survivors of a disaster such as an epidemic or a massive hunt, are confined into a small area. The survivors will carry an allele that is dominant and will have the same phenotype. This situation could be caused by war, earthquakes or even plagues. Whatever the reason, the genetically distinct population that remains could be prone to genetic drift. Walsh Lewens, Walsh and Ariew define drift as a departure from expected values due to differences in fitness. They give the famous example of twins who are genetically identical and share the same phenotype, but one is struck by lightning and dies, whereas the other lives to reproduce. This kind of drift could play a very important part in the evolution of an organism. But, it's not the only way to develop. The primary alternative is a process known as natural selection, in which phenotypic variation in a population is maintained by mutation and migration. Stephens argues there is a significant difference between treating the phenomenon of drift as an actual cause or force, and treating other causes such as migration and selection mutation as causes and forces. Stephens claims that a causal process explanation of drift permits us to differentiate it from the other forces, and this distinction is essential. He argues further that drift has direction, i.e., it tends to eliminate heterozygosity. It also has a size, which is determined based on population size. Evolution by Lamarckism In high school, students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution, also referred to as “Lamarckism”, states that simple organisms develop into more complex organisms through taking on traits that are a product of the use and abuse of an organism. Lamarckism is typically illustrated with an image of a giraffe extending its neck to reach leaves higher up in the trees. This process would cause giraffes to give their longer necks to their offspring, who would then grow even taller. Lamarck, a French Zoologist, introduced a revolutionary concept in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on 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 make this claim but he was thought of as the first to offer the subject a thorough and general treatment. The popular narrative is that Lamarckism grew into an opponent to Charles Darwin's theory of evolution by natural selection and that the two theories battled each other in the 19th century. Darwinism eventually triumphed and led to the development of what biologists call the Modern Synthesis. This theory denies 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 supported the notion that acquired characters could be passed on to future generations. However, this concept was never a key element of any of their theories on evolution. This is partly 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 amount of evidence to support the heritability of acquired characteristics. This is also known as “neo Lamarckism”, or more often epigenetic inheritance. This is a variant that is as reliable as the popular Neodarwinian model. Evolution through adaptation One of the most widespread misconceptions about evolution is that it is a result of a kind of struggle to survive. This view misrepresents natural selection and ignores the other forces that drive evolution. The struggle for survival is more precisely described as a fight to survive within a specific environment, which can include not just other organisms, but also the physical environment. Understanding adaptation is important to comprehend evolution. It refers to a specific feature that allows an organism to survive and reproduce within its environment. It can be a physical feature, such as feathers or fur. It could also be a trait of behavior such as moving to the shade during the heat, or coming out to avoid the cold at night. The ability of an organism to extract energy from its environment and interact with other organisms, as well as their physical environment, is crucial to its survival. The organism must possess the right genes to produce offspring, and must be able to access sufficient food and other resources. The organism should also be able to reproduce at a rate that is optimal for its specific niche. These factors, together with gene flow and mutation result in changes in the ratio of alleles (different types of a gene) in a population's gene pool. As time passes, this shift in allele frequencies could result in the emergence of new traits and eventually new species. Many of the characteristics we admire about animals and plants are adaptations, for example, the lungs or gills that extract oxygen from the air, feathers or fur to provide insulation, long legs for running away from predators, and camouflage to hide. However, a complete understanding of adaptation requires paying attention to the distinction between behavioral and physiological traits. Physiological adaptations like thick fur or gills, are physical traits, whereas behavioral adaptations, like the desire to find companions or to move to shade in hot weather, aren't. It is important to note that the absence of planning doesn't cause an adaptation. In 에볼루션 바카라사이트 , a failure to think about the consequences of a decision can render it unadaptive, despite the fact that it might appear sensible or even necessary.