bongooil00

What is Free Evolution? Free evolution is the notion that natural processes can cause organisms to develop over time. This includes the appearance and development of new species. This has been proven by numerous examples of stickleback fish species that can thrive in fresh or saltwater and walking stick insect varieties that have a preference for particular host plants. click through the up coming website page cannot explain fundamental changes to basic body plans. Evolution through Natural Selection The evolution of the myriad living organisms on Earth is an enigma that has intrigued scientists for many centuries. The most well-known explanation is that of Charles Darwin's natural selection process, a process that occurs when better-adapted individuals survive and reproduce more effectively than those less well adapted. As time passes, the number of individuals who are well-adapted grows and eventually creates a new species. Natural selection is a process that is cyclical and involves the interaction of three factors: variation, reproduction and inheritance. Variation is caused by mutations and sexual reproduction both of which increase the genetic diversity within a species. Inheritance refers the transmission of a person's genetic traits, which include recessive and dominant genes, to their offspring. Reproduction is the process of producing fertile, viable offspring, which includes both asexual and sexual methods. Natural selection can only occur when all these elements are in equilibrium. For instance, if an allele that is dominant at a gene allows an organism to live and reproduce more often than the recessive allele, the dominant allele will become more prevalent within the population. But if the allele confers a disadvantage in survival or decreases fertility, it will disappear from the population. The process is self reinforcing, which means that an organism that has an adaptive characteristic will live and reproduce more quickly than one with a maladaptive characteristic. The greater an organism's fitness which is measured by its ability to reproduce and survive, is the greater number of offspring it will produce. Individuals with favorable traits, like having a long neck in Giraffes, or the bright white color patterns on male peacocks, are more likely than others to reproduce and survive and eventually lead to them becoming the majority. Natural selection is only an element in the population and not on individuals. This is a major distinction from the Lamarckian theory of evolution, which argues that animals acquire characteristics through use or neglect. For instance, if the Giraffe's neck grows longer due to stretching to reach prey, its offspring will inherit a larger neck. The length difference between generations will persist until the giraffe's neck becomes too long that it can no longer breed with other giraffes. Evolution through Genetic Drift Genetic drift occurs when the alleles of the same gene are randomly distributed in a group. At some point, only one of them will be fixed (become common enough that it can no longer be eliminated through natural selection) and the other alleles will drop in frequency. In extreme cases this, it leads to a single allele dominance. Other alleles have been virtually eliminated and heterozygosity diminished to zero. In a small population this could result in the complete elimination of recessive alleles. This is known as the bottleneck effect. It is typical of the evolution process that occurs when a large number individuals migrate to form a group. A phenotypic bottleneck could happen when the survivors of a disaster such as an epidemic or a mass hunting event, are condensed within a narrow area. The survivors will be mostly homozygous for the dominant allele which means they will all have the same phenotype and will consequently share the same fitness characteristics. This situation might be the result of a war, earthquake, or even a plague. The genetically distinct population, if left susceptible to genetic drift. Walsh, Lewens and Ariew define drift as a departure from expected values due to differences in fitness. They give a famous example of twins that are genetically identical and have identical phenotypes, and yet one is struck by lightning 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 is not the only method to develop. Natural selection is the main alternative, in which mutations and migration keep the phenotypic diversity in a population. Stephens claims that there is a major difference between treating the phenomenon of drift as a force or as a cause and considering other causes of evolution such as mutation, selection and migration as forces or causes. Stephens claims that a causal process explanation of drift permits us to differentiate it from other forces, and that this distinction is essential. He argues further that drift is both a direction, i.e., it tends to eliminate heterozygosity. It also has a size, which is determined by population size. Evolution by Lamarckism In high school, students study biology they are often introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution is commonly known as “Lamarckism” and it asserts that simple organisms evolve into more complex organisms through the inheritance of traits that result from an organism's natural activities, use and disuse. click through the up coming website is typically illustrated by the image of a giraffe stretching its neck further to reach the higher branches in the trees. This would result in giraffes passing on their longer necks to offspring, who would then grow even taller. Lamarck, a French Zoologist from France, presented an innovative idea in his opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on organic transformation. According to Lamarck, living things evolved from inanimate matter through a series gradual steps. Lamarck was not the first to propose this but he was thought of as the first to provide the subject a comprehensive and general explanation. The most popular story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were competing during the 19th century. Darwinism ultimately prevailed and led to what biologists call the Modern Synthesis. The theory argues that acquired traits are passed down from generation to generation and instead, it claims that organisms evolve through the selective influence of environmental factors, such as Natural Selection. Although Lamarck supported the notion of inheritance by acquired characters and his contemporaries spoke of this idea but it was not an integral part of any of their evolutionary theories. This is partly due to the fact that it was never validated scientifically. It's been over 200 years since the birth of Lamarck and in the field of 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. It is a version of evolution that is as relevant as the more popular Neo-Darwinian theory. Evolution by Adaptation One of the most popular misconceptions about evolution is that it is driven by a type of struggle to survive. In reality, this notion misrepresents natural selection and ignores the other forces that determine the rate of evolution. The struggle for survival is more precisely described as a fight to survive within a particular environment, which may be a struggle that involves not only other organisms, but as well the physical environment. Understanding adaptation is important to comprehend evolution. The term “adaptation” refers to any specific characteristic that allows an organism to survive and reproduce in its environment. It can be a physical structure, like fur or feathers. It could also be a trait of behavior that allows you to move into the shade during the heat, or moving out to avoid the cold at night. The ability of a living thing to extract energy from its environment and interact with other organisms and their physical environments is essential to its survival. The organism must have the right genes to generate offspring, and it must be able to access sufficient food and other resources. The organism should be able to reproduce itself at the rate that is suitable for its particular niche. These factors, together with mutations and gene flow can cause an alteration in the ratio of different alleles in the gene pool of a population. As time passes, this shift in allele frequency can result in the development of new traits, and eventually new species. A lot of the traits we admire about animals and plants are adaptations, like the lungs or gills that extract oxygen from the air, fur or feathers to protect themselves, long legs for running away from predators and camouflage to hide. To comprehend adaptation it is crucial to distinguish between behavioral and physiological characteristics. Physiological adaptations like the thick fur or gills are physical traits, while behavioral adaptations, like the tendency to seek out companions or to move into the shade in hot weather, aren't. Furthermore it is important to remember that a lack of forethought is not a reason to make something an adaptation. In fact, a failure to consider the consequences of a decision can render it unadaptive, despite the fact that it appears to be sensible or even necessary.