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What is Free Evolution? Free evolution is the idea that the natural processes of living organisms can lead to their development over time. This includes the evolution of new species as well as the alteration of the appearance of existing ones. This is evident in many examples such as the stickleback fish species that can thrive in saltwater or fresh water and walking stick insect types that prefer particular host plants. These reversible traits, however, cannot be the reason for fundamental changes in body plans. Evolution through Natural Selection The evolution of the myriad living organisms on Earth is an enigma that has intrigued scientists for decades. Charles Darwin's natural selection theory is the most well-known explanation. This is because those who are better adapted survive and reproduce more than those who are less well-adapted. As time passes, a group of well adapted individuals grows and eventually becomes a new species. Natural selection is an ongoing process that involves the interaction of three factors: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within a species. Inheritance refers the transmission of a person’s genetic characteristics, which includes both dominant and recessive genes, to their offspring. Reproduction is the process of generating fertile, viable offspring. 에볼루션바카라 can be achieved via sexual or asexual methods. All of these variables must be in harmony to allow natural selection to take place. If, for instance the dominant gene allele allows an organism to reproduce and live longer than the recessive gene allele The dominant allele will become more prevalent in a population. If the allele confers a negative survival advantage or reduces the fertility of the population, it will go away. The process is self-reinforcing, which means that an organism that has a beneficial trait will survive and reproduce more than an individual with a maladaptive trait. 바카라 에볼루션 fit an organism is as measured by its capacity to reproduce and survive, is the greater number of offspring it will produce. People with desirable traits, like a longer neck in giraffes and bright white colors in male peacocks are more likely to survive and produce offspring, so they will eventually make up the majority of the population over time. Natural selection is a factor in populations and not on individuals. This is a significant distinction from the Lamarckian theory of evolution which argues that animals acquire traits through use or disuse. If a giraffe extends its neck in order to catch prey and the neck grows longer, then the offspring will inherit this trait. The differences in neck length between generations will persist until the neck of the giraffe becomes so long that it can no longer breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles of one gene are distributed randomly in a group. Eventually, one of them will reach fixation (become so widespread that it cannot be eliminated through natural selection) and the other alleles drop to lower frequency. In extreme cases, this leads to one allele dominance. Other alleles have been virtually eliminated and heterozygosity decreased to a minimum. In a small population this could result in the total elimination of recessive allele. This scenario is called the bottleneck effect and is typical of the evolution process that occurs when an enormous number of individuals move to form a population. A phenotypic bottleneck may also occur when the survivors of a disaster such as an outbreak or mass hunting event are confined to an area of a limited size. The survivors will have a dominant allele and thus will have the same phenotype. This could be caused by a war, earthquake or even a cholera outbreak. The genetically distinct population, if it remains, could be susceptible to genetic drift. Walsh, Lewens and Ariew define drift as a departure from expected values due to differences in fitness. They give the famous example of twins who are both genetically identical and share the same phenotype. However, one is struck by lightning and dies, whereas the other lives to reproduce. This kind of drift could be crucial in the evolution of an entire species. However, it's not the only way to evolve. 에볼루션 슬롯게임 is a process known as natural selection, where phenotypic variation in a population is maintained by mutation and migration. Stephens claims that there is a significant difference between treating drift as a force or an underlying cause, and considering other causes of evolution like mutation, selection, and migration as forces or causes. Stephens claims that a causal process account of drift allows us separate it from other forces, and this distinction is crucial. He argues further that drift is both direction, i.e., it tends to reduce heterozygosity. It also has a size which is determined by population size. Evolution through Lamarckism When high school students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution, commonly referred to as “Lamarckism, states that simple organisms develop into more complex organisms through taking on traits that are a product of the organism's use and misuse. Lamarckism is usually illustrated with an image of a giraffe extending its neck to reach higher up in the trees. This could cause giraffes to give their longer necks to their offspring, who then grow even taller. Lamarck the French zoologist, presented a revolutionary concept in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the previous thinking on organic transformation. In his view living things evolved from inanimate matter via a series of gradual steps. Lamarck wasn't the only one to suggest this, but he was widely considered to be the first to provide the subject a comprehensive and general overview. The dominant story is that Charles Darwin's theory of natural selection and Lamarckism were rivals during the 19th century. Darwinism eventually prevailed and led to the creation of what biologists refer to as the Modern Synthesis. The theory denies that acquired characteristics can be passed down and instead, it claims that organisms evolve through the selective action of environment factors, including Natural Selection. Lamarck and his contemporaries supported the idea that acquired characters could be passed on to the next generation. However, this notion was never a major part of any of their theories about evolution. This is partly because it was never scientifically tested. It's been more than 200 years since Lamarck was born and, in the age of genomics there is a huge amount of evidence to support the possibility of inheritance of acquired traits. This is also known as “neo Lamarckism”, or more generally epigenetic inheritance. This is a version that is as valid as the popular neodarwinian model. Evolution by the process of adaptation One of the most popular misconceptions about evolution is that it is being driven by a fight for survival. This notion is not true and ignores other forces driving evolution. The struggle for survival is more precisely described as a fight to survive within a particular environment, which can be a struggle that involves not only other organisms but as well the physical environment. Understanding adaptation is important to understand evolution. Adaptation is any feature that allows living organisms to live in its environment and reproduce. It can be a physical feature, like fur or feathers. Or it can be a characteristic of behavior such as moving to the shade during the heat, or escaping the cold at night. The capacity of a living thing to extract energy from its surroundings and interact with other organisms and their physical environments is essential to its survival. The organism should possess the right genes to create offspring and be able find sufficient food and resources. Furthermore, the organism needs to be capable of reproducing at a high rate within its niche. These factors, together with mutation and gene flow can result in a change in the proportion of alleles (different varieties of a particular gene) in the population's gene pool. This change in allele frequency can lead to the emergence of new traits, and eventually, new species as time passes. Many of the features we admire in animals and plants are adaptations. For example lung or gills that draw oxygen from air, fur and feathers as insulation and long legs to get away from predators and camouflage to conceal. However, a proper understanding of adaptation requires attention to the distinction between physiological and behavioral traits. Physical traits such as the thick fur and gills are physical characteristics. Behavioral adaptations are not, such as the tendency of animals to seek companionship or retreat into shade during hot temperatures. It is important to remember that a the absence of planning doesn't make an adaptation. A failure to consider the implications of a choice even if it appears to be rational, may make it unadaptive.