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What is Free Evolution? Free evolution is the notion that natural processes can cause organisms to evolve over time. This includes the creation of new species and change in appearance of existing ones. Many examples have been given of this, including various varieties of fish called sticklebacks that can live in either salt or fresh water, and walking stick insect varieties that are attracted to particular host plants. These are mostly reversible traits however, are not able to explain fundamental changes in basic body plans. Evolution by Natural Selection The development of the myriad living creatures on Earth is a mystery that has fascinated scientists for decades. The best-established explanation is that of Charles Darwin's natural selection, which occurs when individuals that are better adapted survive and reproduce more effectively than those less well adapted. As time passes, a group of well adapted individuals grows and eventually forms a whole new species. Natural selection is an ongoing process that involves the interaction of three factors: variation, inheritance and reproduction. Variation is caused by mutations and sexual reproduction both of which increase the genetic diversity within an animal species. Inheritance refers to the transmission of a person's genetic characteristics, which includes both dominant and recessive genes to their offspring. Reproduction is the process of creating fertile, viable offspring. This can be accomplished through sexual or asexual methods. All of these variables must be in harmony to allow natural selection to take place. For example the case where the dominant allele of a gene can cause an organism to live and reproduce more often than the recessive allele, the dominant allele will be more prevalent within the population. If the allele confers a negative advantage to survival or reduces the fertility of the population, it will go away. The process is self-reinforced, meaning that an organism with a beneficial trait can reproduce and survive longer than one with a maladaptive characteristic. The more offspring an organism produces the more fit it is that is determined by its capacity to reproduce and survive. Individuals with favorable traits, such as longer necks in giraffes, or bright white patterns of color in male peacocks, are more likely to survive and produce offspring, which means they will eventually make up the majority of the population in the future. Natural selection only affects populations, not on individual organisms. This is a significant distinction from the Lamarckian evolution theory which holds that animals acquire traits due to usage or inaction. For instance, if the animal's neck is lengthened by stretching to reach prey and its offspring will inherit a larger neck. The difference in neck length between generations will continue until the neck of the giraffe becomes too long that it can not breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles from one gene are distributed randomly within a population. At some point, one will attain fixation (become so common that it is unable to be removed through natural selection) and other alleles fall to lower frequencies. In the extreme it can lead to one allele dominance. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small group it could lead to the total elimination of the recessive allele. This is known as a bottleneck effect and it is typical of evolutionary process when a large number of individuals move to form a new group. A phenotypic bottleneck may also occur when the survivors of a catastrophe like an outbreak or mass hunt event are concentrated in the same area. The survivors will carry a dominant allele and thus will share the same phenotype. This situation could be caused by war, earthquakes or even plagues. Whatever the reason, the genetically distinct population that is left might be susceptible to genetic drift. Walsh, Lewens, and Ariew use a “purely outcome-oriented” definition of drift as any departure from the expected values for different fitness levels. They provide a well-known example of twins that are genetically identical and have the exact same phenotype and yet one is struck by lightening and dies while the other lives and reproduces. This kind of drift could play a crucial part in the evolution of an organism. However, it's not the only method to evolve. The primary alternative is a process known as natural selection, where phenotypic variation in the population is maintained through mutation and migration. Stephens claims that there is a significant difference between treating drift as a force or a cause and treating other causes of evolution like mutation, selection, and migration as forces or causes. He claims that a causal-process model of drift allows us to distinguish it from other forces and that this distinction is crucial. He argues further that drift has both an orientation, i.e., it tends to eliminate heterozygosity. It also has a size that is determined by the size of the population. Evolution by Lamarckism Biology students in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is commonly called “Lamarckism” and it states that simple organisms grow into more complex organisms via the inheritance of traits that result from the natural activities of an organism use and misuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher branches in the trees. This could cause the necks of giraffes that are longer to be passed onto their offspring who would then become taller. Lamarck Lamarck, a French zoologist, presented an idea that was revolutionary in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the previous thinking on organic transformation. According to Lamarck, living creatures evolved from inanimate matter by a series of gradual steps. Lamarck was not the first to suggest that this might be the case but the general consensus is that he was the one being the one who gave the subject his first comprehensive and thorough treatment. The predominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were competing in the 19th century. Darwinism eventually triumphed and led to the development of what biologists today refer to as the Modern Synthesis. The Modern Synthesis theory denies that acquired characteristics can be acquired through inheritance and instead argues that organisms evolve by the symbiosis of environmental factors, such as natural selection. Lamarck and his contemporaries believed in the notion that acquired characters could be passed down to future generations. However, this idea was never a central part of any of their theories about evolution. This is due in part to the fact that it was never validated scientifically. It's 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 also referred to as “neo Lamarckism”, or more generally epigenetic inheritance. This is a version that is just as valid as the popular Neodarwinian model. Evolution by adaptation One of the most common misconceptions about evolution is its being driven by a struggle to survive. In fact, this view is inaccurate and overlooks the other forces that drive evolution. The fight for survival can be better described as a struggle to survive in a particular environment. This can include not only other organisms but also the physical environment itself. Understanding the concept of adaptation is crucial to comprehend evolution. The term “adaptation” refers to any specific feature that allows an organism to live and reproduce in its environment. 에볼루션게이밍 could be a physical structure like fur or feathers. Or it can be a behavior trait that allows you to move into the shade during hot weather or moving out to avoid the cold at night. An organism's survival depends on its ability to extract energy from the environment and interact with other organisms and their physical environments. The organism must have the right genes for producing offspring and be able find sufficient food and resources. Furthermore, the organism needs to be capable of reproducing itself at a high rate within its environmental niche. These factors, along with gene flow and mutation, lead to an alteration in the percentage of alleles (different varieties of a particular gene) in the population's gene pool. Over time, this change in allele frequencies can result in the emergence of new traits, and eventually new species. Many of the features we appreciate in plants and animals are adaptations. For instance lung or gills that extract oxygen from the air, fur and feathers as insulation long legs to run away from predators and camouflage to conceal. To understand the concept of adaptation, it is important to discern between physiological and behavioral characteristics. Physiological adaptations, such as thick fur or gills are physical traits, whereas behavioral adaptations, such as the desire to find friends or to move to shade in hot weather, aren't. It is also important to remember that a lack of planning does not cause an adaptation. In fact, failure to think about the consequences of a decision can render it unadaptable despite the fact that it may appear to be sensible or even necessary.