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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 development of new species and the alteration of the appearance of existing ones. This is evident in numerous examples of stickleback fish species that can thrive in salt or fresh water, and walking stick insect species that are apprehensive about particular host plants. These reversible traits do not explain the fundamental changes in basic body plans. Evolution through Natural Selection Scientists have been fascinated by the evolution of all the living creatures that inhabit our planet for centuries. The most widely accepted explanation is Darwin's natural selection, an evolutionary process that occurs when better-adapted individuals survive and reproduce more successfully than those less well-adapted. As time passes, the number of well-adapted individuals grows and eventually develops into a new species. Natural selection is a process that is cyclical and involves the interaction of 3 factors that are: reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within a species. Inheritance refers to the transmission of genetic traits, including both dominant and recessive genes, to their offspring. Reproduction is the generation of viable, fertile offspring, which includes both asexual and sexual methods. Natural selection is only possible when all these elements are in balance. If, for instance, a dominant gene allele causes an organism reproduce and last longer than the recessive allele The dominant allele is more prevalent in a group. If the allele confers a negative survival advantage or lowers the fertility of the population, it will go away. This process is self-reinforcing, which means that an organism that has an adaptive trait will live and reproduce far more effectively than one with a maladaptive characteristic. The higher the level of fitness an organism has as measured by its capacity to reproduce and survive, is the more offspring it will produce. People with good traits, like having a longer neck in giraffes or bright white colors in male peacocks are more likely to survive and have offspring, and thus will make up the majority of the population over time. Natural selection is only a force for populations, not on individuals. This is a significant distinction from the Lamarckian evolution theory that states that animals acquire traits through use or lack of use. If a giraffe expands its neck to catch prey and its neck gets longer, then the offspring will inherit this trait. The differences in neck length between generations will continue until the giraffe's neck gets too long that it can not breed with other giraffes. Evolution by Genetic Drift In genetic drift, the alleles at a gene may be at different frequencies within a population by chance 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 it can lead to a single allele dominance. The other alleles are eliminated, and heterozygosity decreases to zero. In a small population 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 occurs when a large number of individuals move to form a new population. A phenotypic bottleneck may occur when survivors of a catastrophe, such as an epidemic or a massive hunt, are confined within a narrow area. The survivors will be largely homozygous for the dominant allele, which means they will all have the same phenotype and will consequently have the same fitness traits. This may be caused by war, earthquake or even a cholera outbreak. The genetically distinct population, if it is left, could be susceptible to genetic drift. Walsh Lewens, Lewens, and Ariew utilize Lewens, Walsh, and Ariew use a “purely outcome-oriented” definition of drift as any deviation from the expected values for different fitness levels. 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 is able to reproduce. This kind of drift could be vital to the evolution of the species. It's not the only method of evolution. The primary alternative is to use a process known as natural selection, in which the phenotypic diversity of the population is maintained through mutation and migration. Stephens claims that there is a major distinction between treating drift as a force, or an underlying cause, and considering other causes of evolution such as selection, mutation, and migration as forces or causes. He claims that a causal process account of drift allows us to distinguish it from other forces, and that this distinction is vital. He argues further that drift has a direction, i.e., it tends to reduce heterozygosity. It also has a size, which is determined by the size of the population. Evolution through Lamarckism Biology students in high school are often exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution is generally known as “Lamarckism” and it asserts that simple organisms evolve into more complex organisms by the inheritance of traits that result from the natural activities of an organism, use and disuse. Lamarckism is usually illustrated with a picture of a giraffe extending its neck to reach higher up in the trees. This would cause giraffes to pass on their longer necks to offspring, which then grow even taller. Lamarck Lamarck, a French Zoologist, introduced 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. In his opinion living things evolved from inanimate matter through an escalating series of steps. click through the up coming website page 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 its first broad and comprehensive treatment. The prevailing story is that Lamarckism was a rival to Charles Darwin's theory of evolutionary natural selection, and that the two theories fought it out in the 19th century. Darwinism eventually triumphed and led to the development of what biologists now refer to as the Modern Synthesis. The theory argues that acquired characteristics can be inherited and instead suggests that organisms evolve through the action of environmental factors, such as natural selection. Lamarck and his contemporaries endorsed the idea that acquired characters could be passed down to the next generation. However, this notion was never a key element of any of their evolutionary theories. This is due in part to the fact that it was never tested scientifically. However, it has been more than 200 years since Lamarck was born and, in the age of genomics, there is a large body of evidence supporting the heritability of acquired characteristics. This is also known as “neo Lamarckism”, or more generally epigenetic inheritance. It is a form of evolution that is as valid as the more popular Neo-Darwinian theory. Evolution through the process of 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 certain environment. This can include not only other organisms but also the physical environment itself. Understanding adaptation is important to understand evolution. It refers to a specific characteristic that allows an organism to live and reproduce within its environment. It could be a physical structure such as feathers or fur. It could also be a behavior trait, like moving to the shade during hot weather or coming out to avoid the cold at night. The survival of an organism depends on its ability to draw energy from the environment and interact with other organisms and their physical environments. The organism must have the right genes to create offspring, and it should be able to find enough food and other resources. Furthermore, the organism needs to be capable of reproducing itself in a way that is optimally within its niche. These elements, in conjunction with gene flow and mutation can result in a change in the proportion of alleles (different types of a gene) in the population's gene pool. This change in allele frequency could lead to the development of new traits, and eventually new species over time. Many of the features that we admire in animals and plants are adaptations, such as the lungs or gills that extract oxygen from the air, feathers or fur to protect themselves, long legs for running away from predators, and camouflage for hiding. To understand adaptation it is crucial to distinguish between behavioral and physiological traits. Physical characteristics like the thick fur and gills 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. Additionally, it is important to understand that lack of planning is not a reason to make something an adaptation. In fact, failure to think about the consequences of a choice can render it ineffective even though it might appear sensible or even necessary.