What is Free Evolution?
Free evolution is the idea that the natural processes of living organisms can lead them to evolve over time. This includes the emergence and development of new species.
This has been proven by many examples of stickleback fish species that can thrive in salt or fresh water, and walking stick insect species that are apprehensive about specific host plants. These typically reversible traits do not explain the fundamental changes in the body's basic plans.
Evolution by Natural Selection
Scientists have been fascinated by the evolution of all living creatures that inhabit our planet for centuries. The most well-known explanation is that of 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. Over time, the population of well-adapted individuals becomes larger and eventually forms a new species.
Natural selection is a cyclical process that involves the interaction of three elements including inheritance, variation, and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within the species. Inheritance is the passing of a person's genetic traits to their offspring that includes dominant and recessive alleles. Reproduction is the production of fertile, viable offspring, which includes both asexual and sexual methods.
Natural selection can only occur when all of these factors are in balance. If, for example the dominant gene allele allows an organism to reproduce and survive more than the recessive gene The dominant allele is more common in a population. However, if the gene confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. This process is self-reinforcing which means that an organism that has a beneficial trait can reproduce and survive longer than one with an unadaptive trait. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the greater number of offspring it will produce. Individuals with favorable traits, like the long neck of Giraffes, or the bright white color patterns on male peacocks are more likely than others to reproduce and survive, which will eventually lead to them becoming the majority.
Natural selection only affects populations, not individual organisms. This is a major distinction from the Lamarckian theory of evolution which states that animals acquire traits through use or disuse. For example, if a Giraffe's neck grows longer due to reaching out to catch prey and its offspring will inherit a larger neck. The difference in neck size between generations will continue to increase until the giraffe is no longer able to reproduce with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when alleles of the same gene are randomly distributed in a population. Eventually, only one will be fixed (become common enough to no longer be eliminated through natural selection) and the other alleles diminish in frequency. This can lead to a dominant allele in the extreme. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small number of people it could result in the complete elimination of the recessive gene. This is known as the bottleneck effect. It is typical of an evolution process that occurs when a large number individuals migrate to form a population.
A phenotypic 'bottleneck' can also occur when the survivors of a catastrophe such as an outbreak or mass hunting event are confined to an area of a limited size. The survivors will have a dominant allele and thus will share the same phenotype. This situation could be caused by earthquakes, war, or even plagues. Whatever the reason, the genetically distinct population that remains is prone to genetic drift.
Walsh Lewens, Walsh and Ariew define drift as a deviation from expected values due to differences in fitness. They give the famous example of twins that are genetically identical and have exactly the same phenotype. However, one is struck by lightning and dies, but the other lives to reproduce.
This kind of drift can play a crucial role in the evolution of an organism. But, it's not the only way to progress. The most common alternative is to use a process known as natural selection, in which the phenotypic variation of an individual is maintained through mutation and migration.
Stephens asserts that there is a major difference between treating the phenomenon of drift as a force or a cause and treating other causes of evolution such as selection, mutation and migration as forces or causes. He argues that a causal-process model of drift allows us to distinguish it from other forces and that this differentiation is crucial. He further argues that drift has an orientation, i.e., it tends towards eliminating heterozygosity. It also has a size, which is determined by the size of the population.
Evolution by Lamarckism
When students in high school study biology they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, often called "Lamarckism which means 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 the image of a giraffe that extends its neck further to reach higher up in the trees. This process would cause giraffes to pass on their longer necks to their offspring, who then grow even taller.
Lamarck Lamarck, a French Zoologist from France, presented a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. According to 에볼루션카지노 , living things evolved from inanimate material through a series gradual steps. Lamarck was not the first to make this claim but he was thought of as the first to provide the subject a comprehensive and general overview.
The predominant story is that Charles Darwin's theory on natural selection and Lamarckism were competing in the 19th Century. Darwinism eventually prevailed and led to the development of what biologists refer to as the Modern Synthesis. The theory argues that traits acquired through evolution can be acquired through inheritance and instead, it argues that organisms develop through the action of environmental factors, like natural selection.
While Lamarck believed in the concept of inheritance through 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 largely due 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 that supports the possibility of inheritance of acquired traits. This is referred to as "neo Lamarckism", or more generally epigenetic inheritance. It is a version of evolution that is just as relevant as the more popular Neo-Darwinian model.
Evolution by the process of adaptation
One of the most commonly-held misconceptions about evolution is that it is being driven by a struggle for survival. This is a false assumption and overlooks other forces that drive evolution. The struggle for survival is more accurately described as a struggle to survive within a specific environment, which could involve not only other organisms, but as well the physical environment.
Understanding the concept of adaptation is crucial to comprehend evolution. The term "adaptation" refers to any characteristic that allows a living thing to live in its environment and reproduce. It could be a physical structure, such as feathers or fur. Or it can be a trait of behavior that allows you to move towards shade during the heat, or escaping the cold at night.
The survival of an organism depends on its ability to obtain energy from the environment and interact with other organisms and their physical environments. The organism needs to have the right genes to produce offspring, and it should be able to access sufficient food and other resources. The organism must also be able to reproduce itself at an amount that is appropriate for its specific niche.
These elements, in conjunction with mutation and gene flow can result in a change in the proportion of alleles (different varieties of a particular gene) in a population's gene pool. Over time, this change in allele frequencies could result in the emergence of new traits, and eventually new species.
A lot of the traits 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 comprehend adaptation, it is important to discern between physiological and behavioral traits.
Physical traits such as thick fur and gills are physical traits. Behavioral adaptations are not 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. Inability to think about the implications of a choice even if it appears to be logical, can cause it to be unadaptive.