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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. A variety of examples have been provided of this, including various varieties of fish called sticklebacks that can live in either fresh or salt water and walking stick insect varieties that prefer specific host plants. These mostly reversible trait permutations, however, cannot be the reason for fundamental changes in body plans. Evolution by Natural Selection The evolution of the myriad living creatures on Earth is a mystery that has intrigued scientists for decades. Charles Darwin's natural selectivity is the best-established explanation. This happens when people who are more well-adapted have more success in reproduction and survival than those who are less well-adapted. As time passes, the number of individuals who are well-adapted grows and eventually develops into a new species. Natural selection is a cyclical process that involves the interaction of three factors: variation, inheritance and reproduction. Sexual reproduction and mutation increase the genetic diversity of a species. Inheritance is the term used to describe the transmission of a person’s genetic traits, including recessive and dominant genes and their offspring. Reproduction is the production of fertile, viable offspring, which includes both sexual and asexual methods. Natural selection is only possible when all of these factors are in balance. For example when a dominant allele at the gene causes an organism to survive and reproduce more often than the recessive allele the dominant allele will become more prominent within 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 with an adaptive trait will live and reproduce more quickly than those with a maladaptive trait. The more offspring an organism produces the more fit it is which is measured by its ability to reproduce and survive. People with desirable traits, like having a longer neck in giraffes and bright white colors in male peacocks are more likely be able to survive and create offspring, and thus will eventually make up the majority of the population over time. Natural selection is only a factor in populations and not on individuals. This is a significant distinction from the Lamarckian evolution theory which holds that animals acquire traits due to use or lack of use. If a giraffe extends its neck to reach prey and the neck grows larger, then its children will inherit this characteristic. The difference in neck size between generations will continue to grow until the giraffe is unable to reproduce with other giraffes. Evolution through Genetic Drift In genetic drift, alleles within a gene can be at different frequencies within a population by chance events. In the end, only one will be fixed (become widespread enough to not longer be eliminated by natural selection), and the other alleles will decrease in frequency. In extreme cases this, it leads to a single allele dominance. The other alleles are eliminated, and heterozygosity falls to zero. In a small group this could lead to the complete elimination the recessive gene. This scenario is called the bottleneck effect. It is typical of an evolution process that occurs when the number of individuals migrate to form a population. A phenotypic bottleneck may also occur when the survivors of a catastrophe such as an outbreak or mass hunt incident are concentrated in the same area. The survivors will carry an allele that is dominant and will have the same phenotype. This could be caused by a conflict, earthquake or even a cholera outbreak. 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 the expected value due to differences in fitness. They provide the famous case of twins who are both genetically identical and have exactly the same phenotype. However one is struck by lightning and dies, whereas the other is able to reproduce. This kind of drift could play a crucial part in the evolution of an organism. However, it is not the only way to progress. The main alternative is a process known as natural selection, where phenotypic variation in an individual is maintained through mutation and migration. Stephens argues that there is a major difference between treating the phenomenon of drift as a force or an underlying cause, and considering other causes of evolution, such as 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 crucial. He argues further that drift has an orientation, i.e., it tends towards eliminating heterozygosity. It also has a size which is determined based on the size of the population. Evolution by Lamarckism When high school students take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution is commonly known as “Lamarckism” and it states that simple organisms develop into more complex organisms by the inheritance of traits which result from the natural activities of an organism use and misuse. Lamarckism is usually illustrated with the image of a giraffe stretching its neck longer to reach the higher branches in the trees. This would cause the necks of giraffes that are longer to be passed on to their offspring who would then grow even taller. Lamarck was a French Zoologist. In his lecture to begin his course on invertebrate Zoology at the Museum of Natural History in Paris on 17 May 1802, he introduced a groundbreaking concept that radically challenged the conventional wisdom about organic transformation. In 에볼루션카지노사이트 evolutionkr living things had evolved from inanimate matter via the gradual progression of events. Lamarck wasn't the first to propose this, but he was widely considered to be the first to give the subject a thorough and general treatment. The dominant story is that Charles Darwin's theory on natural selection and Lamarckism were competing in the 19th century. Darwinism ultimately prevailed, leading to what biologists call the Modern Synthesis. The theory argues that acquired traits are passed down from generation to generation and instead argues organisms evolve by the selective action of environment factors, such as Natural Selection. Lamarck and his contemporaries believed in the notion that acquired characters could be passed on to future generations. However, this concept was never a central part of any of their theories on evolution. This is due to the fact that it was never scientifically tested. It has been more than 200 year since Lamarck's birth, and in the age genomics, there is a growing evidence-based body of evidence to support the heritability-acquired characteristics. This is referred to as “neo Lamarckism”, or more often epigenetic inheritance. This is a model that is as valid as the popular neodarwinian model. Evolution by the process of adaptation One of the most widespread misconceptions about evolution is that it is driven by a sort of struggle to survive. In reality, this notion is a misrepresentation of natural selection and ignores the other forces that are driving evolution. The fight for survival is more accurately described as a struggle to survive in a specific environment. This could be a challenge for not just other living things but also the physical environment itself. Understanding the concept of adaptation is crucial to understand evolution. Adaptation refers to any particular feature that allows an organism to live and reproduce within its environment. It can be a physical feature, such as feathers or fur. It could also be a characteristic of behavior that allows you to move into the shade during the heat, or escaping the cold at night. An organism's survival depends on its ability to extract energy from the surrounding environment and interact with other living organisms and their physical surroundings. The organism should possess the right genes to produce offspring and to be able to access sufficient food and resources. Furthermore, the organism needs to be capable of reproducing at an optimal rate within its niche. These elements, in conjunction with mutation and gene flow, lead to an alteration in the percentage of alleles (different forms of a gene) in a population's gene pool. This change in allele frequency could lead to the development of novel traits and eventually new species as time passes. Many of the characteristics we appreciate in plants and animals are adaptations. For example, lungs or gills that extract oxygen from the air feathers and fur as insulation long legs to run away from predators and camouflage for hiding. However, a proper understanding of adaptation requires paying attention to the distinction between the physiological and behavioral characteristics. Physiological traits like large gills and thick fur are physical characteristics. The behavioral adaptations aren't like the tendency of animals to seek companionship or to retreat into the shade in hot weather. Furthermore it is important to remember that a lack of thought does not mean that something is an adaptation. Inability to think about the implications of a choice even if it appears to be rational, may make it inflexible.