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What is Free Evolution? Free evolution is the concept that the natural processes of living organisms can lead to their development over time. This includes the emergence and development of new species. Numerous examples have been offered of this, including various varieties of stickleback fish that can live in either fresh or salt water and walking stick insect varieties that favor specific host plants. These mostly reversible trait permutations can't, however, be the reason for fundamental changes in body plans. Evolution by Natural Selection The development of the myriad of living organisms on Earth is a mystery that has fascinated scientists for many centuries. Charles Darwin's natural selectivity is the best-established explanation. This happens when those who are better adapted are able to reproduce faster and longer than those who are less well-adapted. Over time, a population of well adapted individuals grows and eventually becomes a new species. Natural selection is an ongoing process that is characterized by the interaction of three factors that are inheritance, variation and reproduction. Variation is caused by mutation and sexual reproduction, both of which increase the genetic diversity of an animal species. Inheritance is the transfer of a person's genetic traits to their offspring which includes both recessive and dominant alleles. Reproduction is the generation of fertile, viable offspring which includes both sexual and asexual methods. Natural selection can only occur when all of these factors are in equilibrium. If, for instance the dominant gene allele causes an organism reproduce and live longer than the recessive allele, then the dominant allele becomes more prevalent in a population. If the allele confers a negative advantage to survival or reduces the fertility of the population, it will go away. This process is self-reinforcing meaning that an organism with a beneficial characteristic is more likely to survive and reproduce than one with an unadaptive characteristic. The more offspring that an organism has the more fit it is that is determined by its capacity to reproduce itself and survive. People with good characteristics, such as a long neck in Giraffes, or the bright white color patterns on male peacocks, are more likely than others to live and reproduce which eventually leads to them becoming the majority. Natural selection only affects populations, not individual organisms. This is a significant distinction from the Lamarckian evolution theory, which states that animals acquire traits through the use or absence of use. If a giraffe extends its neck in order to catch prey, and the neck becomes larger, then its offspring will inherit this trait. The differences in neck length between generations will persist until the neck of the giraffe becomes too long to no longer breed with other giraffes. Evolution by Genetic Drift In genetic drift, alleles at a gene may be at different frequencies in a population through random events. In the end, only one will be fixed (become common enough that it can no more be eliminated through natural selection), and the rest of the alleles will drop in frequency. In extreme cases this, it leads to dominance of a single allele. The other alleles are virtually eliminated and heterozygosity diminished to zero. In a small population this could result in the complete elimination of recessive alleles. Such a scenario would be called a bottleneck effect, and it is typical of the kind of evolutionary process when a large number of people migrate to form a new population. A phenotypic 'bottleneck' can also occur when the survivors of a catastrophe like an outbreak or a mass hunting incident are concentrated in a small area. The survivors will have an dominant allele, and will share the same phenotype. This may be the result of a war, an earthquake or even a disease. Whatever the reason, the genetically distinct population that is left might be prone to genetic drift. Walsh Lewens, Walsh and Ariew define drift as a deviation from the expected values due to differences in fitness. They provide the famous case of twins who are both genetically identical and share the same phenotype, but one is struck by lightning and dies, while the other is able to reproduce. This kind of drift can play a crucial part in the evolution of an organism. However, it is not the only method to develop. The most common 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 the phenomenon of drift as an actual cause or force, and treating other causes such as migration and selection as forces and causes. He argues that a causal-process explanation of drift lets us differentiate it from other forces and that this distinction is essential. He also argues that drift has a direction: that is it tends to eliminate heterozygosity, and that it also has a size, which is determined by the size of population. Evolution by Lamarckism In high school, students take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution, also referred to as “Lamarckism” is based on the idea that simple organisms evolve into more complex organisms inheriting characteristics that are a product of the organism's use and misuse. Lamarckism is typically illustrated with an image of a giraffe stretching its neck to reach higher up in the trees. This could cause the longer necks of giraffes to be passed to their offspring, who would grow taller. Lamarck the 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 previous thinking on organic transformation. According Lamarck, living organisms evolved from inanimate material through a series of gradual steps. Lamarck wasn't the only one to suggest this, but he was widely thought of as the first to provide the subject a comprehensive and general explanation. The predominant story is that Charles Darwin's theory on natural selection and Lamarckism fought during the 19th century. Darwinism eventually prevailed, leading to the development of what biologists refer to as the Modern Synthesis. The theory argues the possibility that acquired traits can be inherited, and instead argues that organisms evolve by the symbiosis of environmental factors, like natural selection. Lamarck and his contemporaries endorsed the idea that acquired characters could be passed down to the next generation. However, this concept was never a major part of any of their theories on evolution. This is due to the fact that it was never scientifically validated. It's been more than 200 years since Lamarck was born and in the age genomics there is a vast amount of evidence that supports the heritability of acquired characteristics. This is sometimes referred to as “neo-Lamarckism” or, more commonly, epigenetic inheritance. It is a version of evolution that is just as valid as the more popular neo-Darwinian model. Evolution through adaptation One of the most common misconceptions about evolution is that it is driven by a type of struggle to survive. This view is inaccurate and overlooks the other forces that drive evolution. The fight for survival can be more precisely described as a fight to survive in a specific environment, which could involve not only other organisms, but also the physical environment. To understand how evolution works, it is helpful to understand what is adaptation. Adaptation is any feature that allows living organisms to live in its environment and reproduce. It can be a physiological structure, like feathers or fur or a behavioral characteristic such as a tendency to move into the shade in hot weather or coming out at night to avoid cold. The capacity of an organism to extract energy from its environment and interact with other organisms as well as their physical environments is essential to its survival. The organism must possess the right genes for producing offspring and to be able to access sufficient food and resources. The organism must also be able reproduce itself at a rate that is optimal for its specific niche. These elements, along with gene flow and mutations can cause changes in the proportion of different alleles within the population's gene pool. As time passes, this shift in allele frequencies can result in the development of new traits and eventually new species. Many of the features that we admire in animals and plants are adaptations, for example, the lungs or gills that extract oxygen from the air, fur or feathers to provide insulation and long legs for running away from predators and camouflage for hiding. To understand adaptation it is essential to distinguish between behavioral and physiological characteristics. Physical characteristics like the thick fur and gills are physical traits. our homepage aren't like the tendency of animals to seek out companionship or retreat into shade in hot temperatures. It is also important to keep in mind that insufficient planning does not make an adaptation. Failure to consider the consequences of a decision even if it appears to be logical, can make it inflexible.