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What is Free Evolution?

Free evolution is the idea that natural processes can cause organisms to develop over time. This includes the appearance and growth of new species.

This is evident in numerous examples such as the stickleback fish species that can live in salt or fresh water, and walking stick insect species that are apprehensive about specific host plants. These mostly reversible trait permutations however, are not able to explain fundamental changes in body plans.

Evolution by Natural Selection

Scientists have been fascinated by the development of all living creatures that inhabit our planet for ages. Charles Darwin's natural selection is the most well-known explanation. This is because those who are better adapted have more success in reproduction and survival than those who are less well-adapted. Over time, a population of well adapted individuals grows and eventually becomes a new species.

Natural selection is a process that is cyclical and involves the interaction of 3 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 refers the transmission of genetic characteristics, which includes recessive and 에볼루션 바카라 dominant genes and their offspring. Reproduction is the process of producing viable, fertile offspring. This can be achieved through sexual or asexual methods.

All of these elements have to be in equilibrium for natural selection to occur. For instance when a dominant allele at one gene can cause an organism to live and reproduce more often than the recessive one, the dominant allele will become more prevalent in the population. If the allele confers a negative survival advantage or lowers the fertility of the population, it will be eliminated. The process is self-reinforcing, meaning that a species with a beneficial trait can reproduce and survive longer than an individual with an inadaptive trait. The more offspring an organism produces the more fit it is that is determined by its capacity to reproduce itself and survive. Individuals with favorable traits, like a longer neck in giraffes and bright white color patterns in male peacocks are more likely to survive and produce offspring, so they will become the majority of the population over time.

Natural selection only affects populations, not on individuals. This is a major distinction from the Lamarckian theory of evolution which states that animals acquire traits through use or neglect. For instance, if the Giraffe's neck grows longer due to stretching to reach prey its offspring will inherit a longer neck. The differences in neck length between generations will continue until the neck of the giraffe becomes so long that it can no longer breed with other giraffes.

Evolution by Genetic Drift

In genetic drift, the alleles at a gene may attain different frequencies in a population through random events. At some point, only one of them will be fixed (become common enough that it can no longer be eliminated through natural selection), and the rest of the alleles will decrease in frequency. This can lead to dominance at the extreme. The other alleles are eliminated, and heterozygosity decreases to zero. In a small group it could lead to the complete elimination of recessive allele. This is known as the bottleneck effect. It is typical of the evolution process that occurs when a large number individuals migrate to form a population.

A phenotypic bottleneck may occur when the survivors of a disaster like an epidemic or a massive hunting event, are condensed into a small area. The survivors will have a dominant allele and thus will share the same phenotype. This situation could be caused by war, earthquakes or even a plague. The genetically distinct population, if it is left susceptible to genetic drift.

Walsh, Lewens and Ariew define drift as a deviation from the expected value due to differences in fitness. They give a famous instance of twins who are genetically identical, share identical phenotypes, but one is struck by lightning and dies, whereas the other lives and reproduces.

This kind of drift could be crucial in the evolution of a species. But, it's not the only way to develop. Natural selection is the primary alternative, where mutations and migration keep phenotypic diversity within a population.

Stephens claims that there is a significant distinction between treating drift as a force or cause, and treating other causes like migration and selection as forces and causes. He argues that a causal-process explanation of drift lets us differentiate it from other forces and this differentiation is crucial. He further argues that drift has a direction: that is, it tends to eliminate heterozygosity, and that it also has a magnitude, that is determined by the size of the population.

Evolution by Lamarckism

Biology students in high school are frequently exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution is often known as "Lamarckism" and it states that simple organisms grow into more complex organisms by the inherited characteristics that are a result of the organism's natural actions usage, use and disuse. Lamarckism is typically illustrated by the image of a giraffe stretching its neck longer to reach the higher branches in the trees. This could result in giraffes passing on their longer necks to their offspring, who would then grow even taller.

Lamarck, a French zoologist, 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. According to Lamarck, living things evolved from inanimate material by a series of gradual steps. Lamarck was not the first to make this claim, but he was widely regarded as the first to provide the subject a comprehensive and general 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 prevailed and led to the development of what biologists now refer to as the Modern Synthesis. The theory denies that acquired characteristics can be passed down and instead, 에볼루션 블랙잭 바카라 무료 (article source) it claims that organisms evolve through the influence of environment factors, including Natural Selection.

Lamarck and his contemporaries supported the notion that acquired characters could be passed on to the next generation. However, this idea was never a central part of any of their theories on evolution. This is partly because it was never tested scientifically.

It's been over 200 year since Lamarck's birth and in the field of age genomics, there is an increasing evidence base that supports the heritability of acquired traits. This is referred to as "neo Lamarckism", or more generally epigenetic inheritance. This is a variant that is as valid as the popular neodarwinian model.

Evolution by the process of 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 accurately described as a struggle to survive within a particular environment, which may include not just other organisms, but also the physical environment itself.

To understand how evolution functions it is beneficial to understand what is adaptation. The term "adaptation" refers to any characteristic that allows living organisms to live in its environment and reproduce. It could be a physiological structure like feathers or fur, or a behavioral trait, such as moving into shade in the heat or leaving at night to avoid the cold.

The capacity of an organism to draw energy from its surroundings and 에볼루션코리아 interact with other organisms and their physical environments is essential to its survival. The organism must possess the right genes to generate offspring, and it should be able to locate enough food and other resources. The organism must be able to reproduce itself at an amount that is appropriate for its particular niche.

These factors, together with gene flow and mutations can cause an alteration in the ratio of different alleles in the gene pool of a population. The change in frequency of alleles could lead to the development of novel traits and 에볼루션코리아 eventually new species over time.

Many of the features we find appealing in animals and plants are adaptations. For instance, lungs or gills that extract oxygen from the air, fur and feathers as insulation, long legs to run away from predators, and camouflage to hide. However, a thorough understanding of adaptation requires a keen eye to the distinction between physiological and behavioral traits.

Physical characteristics like the thick fur and gills are physical characteristics. Behavior adaptations aren't, such as the tendency of animals to seek out companionship or move into the shade in hot temperatures. It is also important to keep in mind that the absence of planning doesn't cause an adaptation. Inability to think about the implications of a choice, even if it appears to be rational, may cause it to be unadaptive.