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What is Free Evolution? Free evolution is the idea that the natural processes that organisms go through can cause them to develop over time. This includes the development of new species as well as the alteration of the appearance of existing species. This has been demonstrated by numerous examples, including stickleback fish varieties that can live in fresh or saltwater and walking stick insect types that prefer specific host plants. These reversible traits do not explain the fundamental changes in basic body plans. Evolution by Natural Selection The evolution of the myriad living organisms on Earth is a mystery that has fascinated scientists for many centuries. The best-established explanation is Charles Darwin's natural selection process, which is triggered when more well-adapted individuals live longer and reproduce more effectively than those who are less well adapted. As time passes, a group of well-adapted individuals expands and eventually becomes a new species. Natural selection is a process that is cyclical and involves the interaction of 3 factors including reproduction, variation and inheritance. Mutation and sexual reproduction increase genetic diversity in the species. Inheritance refers to the transmission of a person’s genetic characteristics, which includes recessive and dominant genes to their offspring. Reproduction is the process of producing fertile, viable offspring. This can be done through sexual or asexual methods. Natural selection only occurs when all of these factors are in balance. If, for example, a dominant gene allele causes an organism reproduce and last longer than the recessive allele then the dominant allele becomes more prevalent in a population. But if the allele confers a disadvantage in survival or reduces fertility, it will disappear from the population. The process is self reinforcing meaning that an organism with an adaptive characteristic will live and reproduce far more effectively than those with a maladaptive feature. The higher the level of fitness an organism has as measured by its capacity to reproduce and endure, is the higher number of offspring it can produce. People with desirable traits, like having a long neck in giraffes, or bright white patterns on male peacocks are more likely than others to live and reproduce and eventually lead to them becoming the majority. Natural selection only acts on populations, not on individual organisms. This is a major distinction from the Lamarckian evolution theory, which states that animals acquire traits through the use or absence of use. For instance, if a Giraffe's neck grows longer due to stretching to reach prey its offspring will inherit a larger neck. The difference in neck length between generations will continue until the giraffe's neck becomes too long that it can no longer breed with other giraffes. Evolution through Genetic Drift In genetic drift, alleles within a gene can be at different frequencies in a population through random events. At some point, only one of them 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 essentially eliminated, and heterozygosity decreases to zero. In a small group this could lead to the complete elimination of the recessive gene. Such a scenario would be called a bottleneck effect, and it is typical of evolutionary process that takes place when a large amount 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 confined to a small area. The survivors will share an dominant allele, and will share the same phenotype. This can be caused by war, earthquakes, or even plagues. The genetically distinct population, if it remains susceptible to genetic drift. Walsh Lewens and Ariew employ Lewens, Walsh, and Ariew use a “purely outcome-oriented” definition of drift as any deviation from expected values for different fitness levels. They give the famous example of twins that are genetically identical and have exactly the same phenotype, but one is struck by lightning and dies, but the other continues to reproduce. This kind of drift could play a very important part in the evolution of an organism. It is not the only method for evolution. The main alternative is to use a process known as natural selection, in which the phenotypic diversity of a population is maintained by mutation and migration. Stephens asserts that there is a major difference between treating the phenomenon of drift as a force or a cause and considering other causes of evolution like mutation, selection and migration as causes or causes. Stephens claims that a causal process explanation of drift permits us to differentiate it from other forces, and this distinction is crucial. He also claims that drift has a direction: that is it tends to reduce heterozygosity. He also claims that it also has a specific magnitude that is determined by the size of the 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, commonly referred to as “Lamarckism” is based on the idea that simple organisms evolve into more complex organisms by inheriting characteristics that result from the organism's use and misuse. Read Significantly more can be illustrated by the giraffe's neck being extended to reach higher levels of leaves in the trees. This process would cause giraffes to give their longer necks to their offspring, which then get taller. Lamarck the French Zoologist from France, presented an innovative idea 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 had evolved from inanimate matter through the gradual progression of events. Lamarck was not the first to propose this but he was regarded as the first to offer the subject a thorough and general overview. The dominant story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were rivals in the 19th Century. Darwinism eventually prevailed and led to the creation of what biologists now 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 influence of environmental factors, including Natural Selection. Although Lamarck believed in the concept of inheritance by acquired characters and his contemporaries spoke of this idea however, it was not a major feature in 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 years since Lamarck was born and, in the age of genomics, there is a large amount of evidence to support the heritability of acquired characteristics. This is referred to as “neo Lamarckism”, or more generally epigenetic inheritance. This is a variant that is as valid as the popular Neodarwinian model. Evolution through adaptation One of the most popular misconceptions about evolution is that it is a result of a kind of struggle for survival. In reality, this notion is inaccurate and overlooks the other forces that drive evolution. The fight for survival can be more accurately described as a struggle to survive within a specific environment, which can include not just other organisms, but also the physical environment. To understand how evolution works, it is helpful to consider what adaptation is. The term “adaptation” refers to any characteristic that allows a living thing to survive in its environment and reproduce. It can be a physiological structure, like feathers or fur, or a behavioral trait like moving to the shade during hot weather or stepping out at night to avoid the cold. The survival of an organism is dependent on its ability to draw energy from the surrounding environment and interact with other organisms and their physical environments. The organism should possess the right genes to create offspring, and be able to find enough food and resources. Moreover, the organism must be capable of reproducing at an optimal rate within its environment. These elements, in conjunction 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. 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 animals and plants are adaptations. For instance, lungs or gills that draw oxygen from air feathers and fur as insulation long legs to run away from predators and camouflage for hiding. However, a proper understanding of adaptation requires a keen eye to the distinction between physiological and behavioral characteristics. Physical traits such as the thick fur and gills are physical characteristics. The behavioral adaptations aren't an exception, for instance, the tendency of animals to seek out companionship or retreat into shade in hot weather. It is also important to note that insufficient planning does not cause an adaptation. In fact, failing to think about the implications of a choice can render it unadaptable, despite the fact that it might appear sensible or even necessary.