What is Free Evolution?
Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the emergence and development of new species.
Many examples have been given of this, such as different kinds of stickleback fish that can live in either salt or fresh water, as well as walking stick insect varieties that favor specific host plants. These typically reversible traits cannot explain fundamental changes to basic body plans.
Evolution by Natural Selection
The evolution of the myriad living creatures on Earth is a mystery that has fascinated scientists for centuries. Charles Darwin's natural selection 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. As time passes, the number of well-adapted individuals grows and eventually forms an entirely new species.
Natural selection is an ongoing process and involves the interaction of three factors that are: reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within an animal species. Inheritance refers to the transmission of a person's genetic traits, including both dominant and recessive genes and their offspring. Reproduction is the production of viable, fertile offspring, which includes both sexual and asexual methods.
Natural selection is only possible when all these elements are in harmony. If, for 에볼루션 블랙잭 , a dominant gene allele causes an organism reproduce and last longer than the recessive gene The dominant allele will become more prevalent in a group. However, 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 trait will survive and reproduce more quickly than those with a maladaptive trait. The more offspring an organism can produce, the greater its fitness, which is measured by its ability to reproduce itself and survive. People with desirable characteristics, such as the long neck of giraffes, or 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 acts on populations, not on individual organisms. This is a crucial distinction from the Lamarckian theory of evolution that states that animals acquire traits either through use or lack of use. If a giraffe stretches its neck to reach prey and its neck gets longer, then its children will inherit this characteristic. The difference in neck length between generations will continue until the giraffe's neck gets so long that it can no longer breed with other giraffes.
에볼루션 블랙잭 by Genetic Drift
Genetic drift occurs when alleles of one gene are distributed randomly within a population. In the end, one will attain fixation (become so common that it can no longer be eliminated by natural selection) and the other alleles drop to lower frequency. This could lead to an allele that is dominant in the extreme. The other alleles have been essentially eliminated and heterozygosity has decreased to a minimum. In a small population this could lead to the complete elimination of the recessive gene. This scenario is called the bottleneck effect and is typical of the evolutionary process that occurs whenever a large number individuals migrate to form a group.
A phenotypic 'bottleneck' can also occur when the survivors of a disaster such as an outbreak or mass hunt event are confined to the same area. The remaining individuals are likely to be homozygous for the dominant allele which means that they will all share the same phenotype and will therefore have the same fitness characteristics. This could be caused by war, earthquakes or even plagues. Whatever the reason the genetically distinct population that remains is prone to genetic drift.
Walsh Lewens, Lewens, and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values of differences in fitness. They give the famous example of twins who are genetically identical and share the same phenotype. However, one is struck by lightning and dies, but the other lives to reproduce.
This type of drift can play a crucial part in the evolution of an organism. It is not the only method of evolution. Natural selection is the most common alternative, in which mutations and migrations maintain the phenotypic diversity of a population.
Stephens asserts that there is a major difference between treating drift as a force or as a cause and considering other causes of evolution such as mutation, selection and migration as causes or causes. Stephens claims that a causal process model of drift allows us to distinguish it from other forces and that this differentiation is crucial. He also argues that drift has a direction, that is it tends to eliminate heterozygosity, and that it also has a size, that is determined by the size of population.
Evolution by Lamarckism
Students of biology in high school are often introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution is commonly known as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inheritance of characteristics that result from an organism's natural activities usage, use and disuse. Lamarckism is typically illustrated with the image of a giraffe extending its neck further to reach the higher branches in the trees. This would cause giraffes' longer necks to be passed onto their offspring who would then become taller.
Lamarck the French Zoologist from France, presented an idea that was revolutionary in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged conventional wisdom on organic transformation. In his view, living things had evolved from inanimate matter via the gradual progression of events. Lamarck was not the first to suggest that this might be the case, but the general consensus is that he was the one having given the subject its first broad and comprehensive treatment.
The predominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were rivals during the 19th century. Darwinism eventually prevailed and led to what biologists call the Modern Synthesis. The theory argues that acquired traits can be passed down and instead argues that organisms evolve through the influence of environment factors, including Natural Selection.
Lamarck and his contemporaries endorsed the notion that acquired characters could be passed down to future generations. However, this notion was never a central part of any of their theories about evolution. This is partly due to the fact that it was never validated scientifically.
It's been over 200 year since Lamarck's birth and in the field of age genomics there is a growing body of evidence that supports the heritability-acquired characteristics. 에볼루션게이밍 is also known as "neo Lamarckism", or more generally epigenetic inheritance. It is a version of evolution that is as valid as the more well-known Neo-Darwinian theory.
Evolution through the process of adaptation
One of the most popular misconceptions about evolution is its being driven by a struggle for survival. This view misrepresents natural selection and ignores the other forces that determine the rate of evolution. The struggle for existence is better described as a struggle to survive in a particular environment. This can include not just other organisms as well as the physical environment.
To understand how evolution works it is important to consider what adaptation is. It refers to a specific feature that allows an organism to survive and reproduce within its environment. It can be a physical structure, like fur or feathers. Or it can be a behavior trait such as moving into the shade during hot weather, or escaping the cold at night.
The capacity of an organism to draw energy from its surroundings and interact with other organisms, as well as their physical environment is essential to its survival. The organism needs to have the right genes to produce offspring, and it must be able to access enough food and other resources. In addition, the organism should be capable of reproducing itself at a high rate within its niche.
These elements, along with gene flow and mutations, can lead to an alteration in the ratio of different alleles in the population's gene pool. This shift in the frequency of alleles can result in the emergence of new traits, and eventually, new species as time passes.
Many of the features we find appealing in animals and plants are adaptations. For example the lungs or gills which extract oxygen from air feathers and fur as insulation, long legs to run away from predators and camouflage to conceal. However, a proper understanding of adaptation requires paying attention to the distinction between physiological and behavioral characteristics.
Physical traits such as the thick fur and gills are physical traits. Behavior adaptations aren't, such as the tendency of animals to seek companionship or retreat into shade during hot weather. It is important to remember that a insufficient planning does not result in an adaptation. Inability to think about the effects of a behavior even if it appears to be rational, could make it inflexible.