What is Free Evolution?
Free evolution is the idea that the natural processes that organisms go through can lead to their development over time. This includes the appearance and growth of new species.
This is evident in numerous examples, including stickleback fish varieties that can live in fresh or saltwater and walking stick insect varieties that have a preference for particular host plants. These reversible traits do not explain the fundamental changes in the basic body plan.
Evolution by Natural Selection
Scientists have been fascinated by the development of all the living creatures that inhabit our planet for many centuries. Charles Darwin's natural selectivity is the most well-known explanation. This process occurs when those who are better adapted have more success in reproduction and
에볼루션 무료체험 survival than those who are less well-adapted. Over time, a community of well-adapted individuals increases and eventually forms a whole new species.
Natural selection is a cyclical process that is characterized by the interaction of three factors: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction, both of which increase the genetic diversity within the species. Inheritance refers to the transmission of genetic characteristics, which includes both dominant and recessive genes and their offspring. Reproduction is the process of generating viable, fertile offspring. This can be done via sexual or asexual methods.
Natural selection is only possible when all these elements are in harmony. If, for example, a dominant gene allele causes an organism reproduce and survive more than the recessive gene allele then the dominant allele is more common in a population. But if the allele confers a disadvantage in survival or decreases fertility, it will disappear from the population. This process is self-reinforcing meaning that an organism with a beneficial trait is more likely to survive and reproduce than an individual with an unadaptive characteristic. The more offspring that an organism has, the greater its fitness which is measured by its capacity to reproduce and survive. Individuals with favorable characteristics, such as the long neck of Giraffes, or the bright white patterns on male peacocks are more likely to others to reproduce and survive which eventually leads to them becoming the majority.
Natural selection only affects populations, not on individuals. This is an important distinction from the Lamarckian theory of evolution, which claims that animals acquire characteristics through use or neglect. If a giraffe expands its neck in order to catch prey and the neck grows longer, then its offspring will inherit this trait. The difference in neck size between generations will increase until the giraffe becomes unable to breed with other giraffes.
Evolution by Genetic Drift
Genetic drift occurs when the alleles of a gene are randomly distributed within a population. In the end, only one will be fixed (become common enough that it can no longer be eliminated by natural selection) and the other alleles diminish in frequency. This could lead to an allele that is dominant at the extreme. The other alleles are essentially eliminated, and heterozygosity is reduced to zero. In a small group this could lead to the complete elimination of recessive gene. This is known as a bottleneck effect and it is typical of evolutionary process that takes place when a lot of people migrate to form a new population.
A phenotypic bottleneck may happen when the survivors of a disaster like an epidemic or a massive hunting event, are concentrated into a small area. The remaining individuals are likely to be homozygous for the dominant allele which means they will all share the same phenotype and will therefore share the same fitness characteristics. This could be caused by war, earthquake or even a disease. Regardless of the cause the genetically distinct group that is left might be susceptible to genetic drift.
Walsh, Lewens,
에볼루션사이트 and
에볼루션 바카라 체험 Ariew use Lewens, Walsh and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values for different fitness levels. They cite the famous example of twins who are both genetically identical and share the same phenotype. However, one is struck by lightning and dies, but the other is able to reproduce.
This type of drift is crucial in the evolution of an entire species. However, it is not the only method to progress. The most common alternative is to use a process known as natural selection, in which the phenotypic diversity of an individual is maintained through mutation and migration.
Stephens argues there is a vast difference between treating the phenomenon of drift as an actual cause or force, and treating other causes like migration and selection mutation as causes and forces. Stephens claims that a causal process account of drift allows us differentiate it from other forces and that this differentiation is crucial. He further argues that drift has an orientation, i.e.,
에볼루션 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 is often called "Lamarckism" and it asserts that simple organisms evolve into more complex organisms through the inheritance of characteristics that are a result of the natural activities of an organism usage, use and disuse. Lamarckism is typically illustrated by the image of a giraffe stretching its neck longer to reach leaves higher up in the trees. This could cause the longer necks of giraffes to be passed to their offspring, who would then grow even taller.
Lamarck was a French zoologist and, in his opening lecture for his course on invertebrate zoology at the Museum of Natural History in Paris on the 17th May 1802, he presented a groundbreaking concept that radically challenged the conventional wisdom about organic transformation. According to him, living things had evolved from inanimate matter via the gradual progression of events. Lamarck was not the first to suggest that this could be the case but his reputation is widely regarded as having given the subject his first comprehensive and comprehensive treatment.
The most popular story is that Charles Darwin's theory on evolution by natural selection and Lamarckism fought during the 19th century. Darwinism eventually won, leading to the development of what biologists call the Modern Synthesis. The theory argues that acquired traits can be passed down through generations and instead argues organisms evolve by the influence of environment factors, including Natural Selection.
Lamarck and his contemporaries endorsed the idea that acquired characters could be passed down to future generations. However, this notion was never a major part of any of their evolutionary theories. This is largely due to the fact that it was never tested scientifically.
But it is now more than 200 years since Lamarck was born and,
에볼루션 무료 바카라 in the age of genomics there is a vast amount of evidence that supports the possibility of inheritance of acquired traits. This is also known as "neo Lamarckism", or more often epigenetic inheritance. It is a variant of evolution that is as valid as the more popular neo-Darwinian model.
Evolution through the process of adaptation
One of the most popular misconceptions about evolution is that it is driven by a sort of struggle for survival. This notion is not true and overlooks other forces that drive evolution.
