What is Free Evolution?
Free evolution is the concept that natural processes can cause organisms to develop over time. This includes the evolution of new species and the transformation of the appearance of existing ones.
Numerous examples have been offered of this, including various varieties of fish called sticklebacks that can be found in salt or fresh water, as well as walking stick insect varieties that are attracted to particular host plants. These mostly reversible traits permutations do not explain the fundamental changes in the basic body plan.
Evolution through Natural Selection
The development of the myriad of living creatures on Earth is a mystery that has intrigued scientists for centuries. The best-established explanation is Darwin's natural selection process, which occurs when individuals that are better adapted survive and reproduce more successfully than those that are less well-adapted. Over time, a community of well adapted individuals grows and eventually creates a new species.
Natural selection is an ongoing process and involves the interaction of three factors that are: reproduction, variation and inheritance. Sexual reproduction and mutation increase the genetic diversity of the species. Inheritance refers to the passing of a person's genetic traits to the offspring of that person, which includes both recessive and dominant alleles. Reproduction is the process of producing viable, fertile offspring, which includes both asexual and sexual methods.
Natural selection can only occur when all of these factors are in equilibrium. For instance, if a dominant allele at one gene causes an organism to survive and reproduce more frequently than the recessive one, the dominant allele will be more common in the population. If the allele confers a negative survival advantage or lowers the fertility of the population, it will be eliminated. This process is self-reinforcing meaning that the organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive feature. The more fit an organism is as measured by its capacity to reproduce and survive, is the more offspring it can produce. People with good characteristics, such as a long neck in the giraffe, or bright white patterns on male peacocks are more likely to others to survive and reproduce, which will eventually lead to them becoming the majority.
Natural selection is only a force for populations, not individuals. This is an important distinction from the Lamarckian theory of evolution, which claims that animals acquire traits through use or neglect. For instance, if the animal's neck is lengthened by reaching out to catch prey and its offspring will inherit a longer neck. The difference in neck size between generations will continue to grow until the giraffe becomes unable to breed with other giraffes.
Evolution through Genetic Drift
In the process of genetic drift, alleles within a gene can reach different frequencies within a population by chance events. At some point, one will reach fixation (become so common that it can no longer be eliminated through natural selection) and other alleles will fall to lower frequency. This can result in a dominant allele at the extreme. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small population, this could lead to the complete elimination of recessive alleles. This scenario is called the bottleneck effect and is typical of the evolution process that occurs when a large number individuals migrate to form a group.
A phenotypic bottleneck could occur when survivors of a catastrophe, such as an epidemic or a massive hunting event, are condensed within a narrow area. The survivors will share a dominant allele and thus will have the same phenotype. This may be caused by war, earthquake or even a disease. The genetically distinct population, if it is left, could be susceptible to genetic drift.
Walsh Lewens, Lewens, and Ariew utilize a "purely outcome-oriented" definition of drift as any deviation from the expected values for differences in fitness. They give a famous example of twins that are genetically identical, have the exact same phenotype but 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's not the only way to evolve. Natural selection is the main alternative, in which mutations and migration keep the phenotypic diversity of a population.
Stephens argues that there is a significant difference between treating drift as a force or a cause and treating other causes of evolution such as mutation, selection and migration as forces or causes. He argues that a causal-process model of drift allows us to separate it from other forces, and this distinction is crucial. He argues further that drift has direction, i.e., it tends to eliminate heterozygosity. It also has a size, which is determined by population size.
Evolution through Lamarckism
Students of biology in high school are often introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution, also referred to as "Lamarckism, states that simple organisms transform into more complex organisms taking on traits that result from an organism's use and disuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher leaves in the trees. This process would cause giraffes to give their longer necks to their offspring, who would then become taller.
Lamarck the French zoologist, presented an idea that was revolutionary in his opening lecture at the Museum of Natural History of Paris. 에볼루션게이밍 challenged the previous thinking on organic transformation. According to him living things had evolved from inanimate matter via an escalating series of steps. Lamarck was not the first to propose this, but he was widely regarded as the first to offer the subject a thorough and general explanation.
The most popular story is that Charles Darwin's theory of natural selection and Lamarckism were competing in the 19th Century. Darwinism ultimately prevailed and led to what biologists call the Modern Synthesis. This theory denies acquired characteristics can be passed down and instead argues organisms evolve by the influence of environment factors, such as Natural Selection.
Lamarck and his contemporaries endorsed the idea that acquired characters could be passed on to future generations. However, this concept was never a key element of any of their theories on evolution. This is partly because it was never scientifically validated.
It's been over 200 year since Lamarck's birth and in the field of age genomics, there is a growing evidence base that supports the heritability of acquired traits. This is often called "neo-Lamarckism" or more commonly, epigenetic inheritance. This is a variant that is as valid as the popular neodarwinian model.
Evolution through adaptation
One of the most widespread misconceptions about evolution is that it is a result of a kind of struggle to survive. This notion is not true and overlooks other forces that drive evolution. The struggle for survival is more effectively described as a struggle to survive in a specific environment, which could be a struggle that involves not only other organisms, but as well the physical environment.
Understanding adaptation is important to understand evolution. Adaptation refers to any particular feature that allows an organism to survive and reproduce in its environment. It could be a physical feature, such as feathers or fur. It could also be a behavior trait that allows you to move to the shade during hot weather or escaping the cold at night.
The capacity of a living thing 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 have the right genes to generate offspring, and it must be able to locate enough food and other resources. The organism should also be able reproduce itself at a rate that is optimal for its particular niche.
These elements, along with gene flow and mutations can cause an alteration in the ratio of different alleles in a population’s gene pool. As time passes, this shift in allele frequencies could result in the emergence of new traits and ultimately new species.
Many of the characteristics we admire in animals and plants are adaptations, for example, lung or gills for removing oxygen from the air, fur or feathers for insulation and long legs for running away from predators and camouflage to hide. However, a thorough understanding of adaptation requires a keen eye to the distinction between physiological and behavioral characteristics.
Physiological adaptations like thick fur or gills, are physical characteristics, whereas behavioral adaptations, like the tendency to search for friends or to move to shade in hot weather, aren't. In 에볼루션 블랙잭 , it is important to remember that a lack of forethought does not make something an adaptation. In fact, a failure to consider the consequences of a choice can render it ineffective, despite the fact that it may appear to be sensible or even necessary.