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What is Free Evolution? Free evolution is the concept that natural processes can lead to the development of organisms over time. This includes the creation of new species and change in appearance of existing ones. A variety of examples have been provided of this, including different varieties of fish called sticklebacks that can be found in salt or fresh water, as well as walking stick insect varieties that are attracted to specific 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 development of all living creatures that inhabit our planet for centuries. Charles Darwin's natural selection is the most well-known explanation. This happens when individuals who are better-adapted survive and reproduce more than those who are less well-adapted. Over time, the population of well-adapted individuals becomes larger and eventually forms an entirely new species. Natural selection is an ongoing process that involves the interaction of three elements: variation, inheritance and reproduction. Sexual reproduction and mutation increase genetic diversity in the species. Inheritance refers to the passing of a person's genetic characteristics to his or her offspring that includes recessive and dominant alleles. Reproduction is the process of producing viable, fertile offspring, which includes both asexual and sexual methods. All of these variables have to be in equilibrium for natural selection to occur. If, for instance an allele of a dominant gene allows an organism to reproduce and survive more than the recessive allele then the dominant allele becomes more common in a population. However, if the gene confers an unfavorable survival advantage or reduces fertility, it will disappear from the population. The process is self-reinforcing, which means that an organism with a beneficial characteristic can reproduce and survive longer than one with an inadaptive trait. The more offspring an organism produces, the greater its fitness that is determined by its ability to reproduce itself and live. People with good traits, like having a long neck in the giraffe, or bright white patterns on male peacocks, are more likely than others to reproduce and survive, which will eventually lead to them becoming the majority. Natural selection is only a force for populations, not on individual organisms. This is a significant distinction from the Lamarckian evolution theory that states that animals acquire traits either through use or lack of use. For example, if a animal's neck is lengthened by stretching to reach for prey and its offspring will inherit a larger neck. The difference in neck size between generations will increase until the giraffe is no longer able to breed with other giraffes. Evolution through Genetic Drift In genetic drift, alleles within a gene can attain different frequencies in a group due to random events. At some point, one will reach fixation (become so widespread that it cannot be eliminated by natural selection) and the other alleles drop to lower frequency. In the extreme, this leads to dominance of a single allele. The other alleles are essentially eliminated and heterozygosity has diminished to zero. In a small group it could result in the complete elimination of recessive gene. This is known as a bottleneck effect and it is typical of the kind of evolutionary process that takes place when a large amount of individuals migrate to form a new group. A phenotypic bottleneck can also occur when survivors of a disaster like an outbreak or a mass hunting event are concentrated in an area of a limited size. The remaining individuals will be mostly homozygous for the dominant allele, which means that they will all have the same phenotype and therefore have the same fitness traits. This could be caused by war, earthquakes or even a plague. The genetically distinct population, if it remains, could be susceptible to genetic drift. Walsh Lewens, Walsh and Ariew define drift as a deviation from expected values due to differences in fitness. They cite a famous instance of twins who are genetically identical and have identical phenotypes but one is struck by lightning and dies, whereas the other lives and reproduces. This type of drift is vital to the evolution of an entire species. It is not the only method of evolution. Natural selection is the primary alternative, in which mutations and migration keep the phenotypic diversity in the population. Stephens argues that there is a significant distinction between treating drift as a force or a cause and treating other causes of evolution like mutation, selection and migration as forces or causes. Stephens claims that a causal process explanation of drift lets us distinguish it from other forces and this distinction is essential. He also claims that drift has a direction: that is, it tends to eliminate heterozygosity, and that it also has a magnitude, which is determined by population size. Evolution by 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 is generally known as “Lamarckism” and it states that simple organisms grow into more complex organisms by the inheritance of traits which result from the organism's natural actions usage, use and disuse. Lamarckism can be illustrated by a giraffe extending its neck to reach higher levels of leaves in the trees. This could cause giraffes' longer necks to be passed onto their offspring who would grow taller. Lamarck was a French zoologist and, in his inaugural lecture for his course on invertebrate zoology at the Museum of Natural History in Paris on the 17th of May in 1802, he presented an innovative concept that completely challenged the conventional wisdom about organic transformation. According to Lamarck, living creatures evolved from inanimate material through a series of gradual steps. Lamarck was not the only one to suggest that this might be the case, but his reputation is widely regarded as having given the subject his first comprehensive and comprehensive analysis. The prevailing story is that Lamarckism grew into a rival to Charles Darwin's theory of evolutionary natural selection and that the two theories battled each other in the 19th century. Darwinism eventually triumphed, leading to the development of what biologists refer to as the Modern Synthesis. The Modern Synthesis theory denies the possibility that acquired traits can be inherited, and instead suggests that organisms evolve through the action of environmental factors, such as natural selection. Although Lamarck believed in the concept of inheritance through acquired characters, and his contemporaries also spoke of this idea however, it was not a central element in any of their theories about evolution. This is partly because it was never scientifically validated. It's been more than 200 year since Lamarck's birth and in the field of genomics, there is an increasing body of evidence that supports the heritability-acquired characteristics. This is also referred to as “neo Lamarckism”, or more generally epigenetic inheritance. This is a version that is as reliable as the popular Neodarwinian model. Evolution by adaptation One of the most widespread misconceptions about evolution is that it is driven by a type of struggle to survive. In reality, this notion is a misrepresentation of natural selection and ignores the other forces that are driving evolution. The struggle for survival is more accurately described as a struggle to survive in a specific environment, which can be a struggle that involves not only other organisms, but also the physical environment itself. To understand how evolution works it is beneficial to understand what is adaptation. It refers to a specific characteristic that allows an organism to live and reproduce within its environment. 에볼루션바카라 can be a physical structure like feathers or fur. It could also be a trait of behavior that allows you to move to the shade during hot weather, or coming out to avoid the cold at night. The ability of an organism to draw energy from its surroundings and interact with other organisms, as well as their physical environments is essential to its survival. The organism must have the right genes to create offspring and to be able to access sufficient food and resources. Furthermore, the organism needs to be capable of reproducing itself at an optimal rate within its environment. These elements, along with gene flow and mutations can result in an alteration in the ratio of different alleles within a population’s gene pool. This change in allele frequency could lead to the development of new traits and eventually new species as time passes. please click for source of the traits we find appealing in animals and plants are adaptations. For example the lungs or gills which extract oxygen from air feathers and fur for insulation, long legs to run away from predators and camouflage to conceal. However, a complete understanding of adaptation requires attention to the distinction between behavioral and physiological traits. Physiological adaptations like the thick fur or gills are physical traits, whereas behavioral adaptations, like the desire to find companions or to retreat into the shade in hot weather, are not. It is important to keep in mind that the absence of planning doesn't cause an adaptation. In fact, failing to think about the consequences of a choice can render it ineffective despite the fact that it may appear to be reasonable or even essential.