• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

What is Free Evolution?

Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the creation of new species and the transformation of the appearance of existing species.

This has been proven by numerous examples such as the stickleback fish species that can thrive in fresh or saltwater and walking stick insect types that prefer specific host plants. These are mostly reversible traits, however, cannot explain fundamental changes in body plans.

Evolution through Natural Selection

The evolution of the myriad living creatures on Earth is an enigma that has fascinated scientists for decades. Charles Darwin's natural selection theory is the best-established explanation. This happens when people who are more well-adapted have more success in reproduction and survival than those who are less well-adapted. Over time, the population of well-adapted individuals 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 of an animal species. Inheritance is the passing of a person's genetic characteristics to the offspring of that person which includes both recessive and dominant alleles. Reproduction is the process of creating viable, fertile offspring. This can be accomplished by both asexual or sexual methods.

All of these variables have to be in equilibrium to allow natural selection to take place. If, for example an allele of a dominant gene causes an organism reproduce and survive more than the recessive gene, then the dominant allele becomes more common in a population. However, if the allele confers an unfavorable survival advantage or reduces fertility, it will disappear from the population. The process is self-reinforcing, meaning that an organism with a beneficial trait will survive and reproduce more than one with an unadaptive characteristic. The higher the level of fitness an organism has which is measured by its ability to reproduce and survive, is the more offspring it can produce. People with good characteristics, such as having a long neck in Giraffes, or the bright white color patterns on male peacocks are more likely to others to live and reproduce and eventually lead to them becoming the majority.

Natural selection is only an element in the population and not on individuals. This is a significant distinction from the Lamarckian theory of evolution which holds that animals acquire traits due to the use or absence of use. For instance, if the animal's neck is lengthened by reaching out to catch prey, its offspring will inherit a longer 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, one of them will attain fixation (become so widespread that it is unable to be removed by natural selection) and other alleles will fall to lower frequency. In the extreme it can lead to dominance of a single allele. The other alleles are essentially eliminated, and heterozygosity decreases to zero. In a small number of people, this could result in the complete elimination the recessive gene. Such a scenario would be called a bottleneck effect, and it is typical of the kind of evolutionary process when a lot of individuals move to form a new population.

A phenotypic bottleneck may occur when survivors of a disaster like an epidemic or a massive hunting event, are concentrated within a narrow area. The surviving individuals will be mostly homozygous for the dominant allele meaning that they all share the same phenotype, and thus share the same fitness characteristics. This situation might be the result of a war, an earthquake or 에볼루션 블랙잭 even a cholera outbreak. Whatever the reason, the genetically distinct population that remains is prone to genetic drift.

Walsh Lewens, 에볼루션 룰렛게이밍 (Dokuwiki write an article) Walsh, and Ariew define drift as a deviation from the expected values due to differences in fitness. They cite a famous example of twins that are genetically identical, have identical phenotypes, but one is struck by lightning and dies, whereas the other lives and reproduces.

This type of drift can play a significant part in the evolution of an organism. But, it's not the only method to progress. Natural selection is the main alternative, in which mutations and migrations maintain phenotypic diversity within the population.

Stephens asserts that there is a big difference between treating the phenomenon of drift as a force or a cause and considering other causes of evolution such as selection, mutation 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 also argues that drift is a directional force: that is it tends to reduce heterozygosity, and that it also has a specific magnitude that is determined by population size.

Evolution through Lamarckism

Biology students in high school are often introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution, commonly referred to as "Lamarckism" which means that simple organisms evolve into more complex organisms through taking on traits that result from the organism's use and misuse. Lamarckism is typically illustrated with an image of a giraffe that extends its neck longer to reach higher up in the trees. This would cause the necks of giraffes that are longer to be passed onto their offspring who would then grow even taller.

Lamarck, a French Zoologist, introduced an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. According Lamarck, living organisms evolved from inanimate matter through a series of gradual steps. Lamarck was not the first to make this claim however he was widely regarded as the first to offer the subject a comprehensive and general explanation.

The popular narrative is that Lamarckism grew into an opponent to Charles Darwin's theory of evolution through natural selection, and that the two theories battled each other in the 19th century. Darwinism eventually prevailed, leading to the development of what biologists today refer to as the Modern Synthesis. The Modern Synthesis theory denies that traits acquired through evolution can be inherited, and instead suggests that organisms evolve by the symbiosis of environmental factors, like natural selection.

While Lamarck supported the notion of inheritance through acquired characters and his contemporaries paid lip-service to this notion however, it was not a central element in any of their evolutionary theorizing. This is partly because it was never scientifically tested.

It has been more than 200 years since the birth of Lamarck and in the field of genomics there is a growing evidence base that supports the heritability of acquired traits. It is sometimes referred to as "neo-Lamarckism" or more often epigenetic inheritance. This is a version that is just as valid as the popular neodarwinian model.

Evolution by Adaptation

One of the most popular misconceptions about evolution is that it is driven by a sort of struggle to survive. In fact, this view is a misrepresentation of natural selection and ignores the other forces that determine the rate of evolution. The fight for survival can be more precisely described as a fight to survive within a particular environment, which could be a struggle that involves not only other organisms, but also the physical environment.

To understand how evolution operates it is beneficial to consider what adaptation is. It is a feature that allows a living organism to live in its environment and reproduce. It could be a physical structure, like feathers or fur. It could also be a characteristic of behavior that allows you to move into the shade during the heat, 에볼루션 바카라 사이트 or coming out to avoid the cold at night.

The capacity of an organism to extract energy from its environment and interact with other organisms, as well as their physical environment, is crucial to its survival. The organism should possess the right genes for producing offspring, and be able to find sufficient food and resources. Moreover, the organism must be capable of reproducing in a way that is optimally within its environmental niche.

These elements, in conjunction with mutation and gene flow result in an alteration in the percentage of alleles (different varieties of a particular gene) in the gene pool of a population. As time passes, this shift in allele frequencies could result in the emergence of new traits and ultimately new species.

A lot of the traits we admire in plants and animals are adaptations. For example the lungs or gills which draw oxygen from air feathers and fur as insulation, long legs to run away from predators and camouflage for hiding. However, a complete understanding of adaptation requires a keen eye to the distinction between the physiological and behavioral characteristics.

Physical traits such as large gills and thick fur are physical characteristics. Behavioral adaptations are not like the tendency of animals to seek out companionship or retreat into shade in hot weather. In addition it is important to remember that lack of planning does not make something an adaptation. In fact, failure to consider the consequences of a decision can render it ineffective despite the fact that it appears to be sensible or even necessary.