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What is Free Evolution?

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

This has been proven by numerous examples of stickleback fish species that can thrive in salt or fresh water, and walking stick insect types that prefer particular host plants. These reversible traits however, are not able to be the reason for fundamental changes in body plans.

Evolution through Natural Selection

Scientists have been fascinated by the evolution of all living creatures that live on our planet for centuries. Charles Darwin's natural selectivity is the best-established explanation. This is because those who are better adapted are able to reproduce faster and 에볼루션 사이트 바카라사이트 (Trade-britanica.trade) longer than those who are less well-adapted. Over time, the population of well-adapted individuals grows and eventually creates an entirely 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 mutation and sexual reproduction both of which increase the genetic diversity within a species. Inheritance is the term used to describe the transmission of a person’s genetic traits, including recessive and dominant genes, to their offspring. Reproduction is the process of producing viable, fertile offspring, which includes both sexual and asexual methods.

All of these variables have to be in equilibrium to allow natural selection to take place. For instance when a dominant allele at a gene allows an organism to live and reproduce more frequently than the recessive allele the dominant allele will become more prevalent within the population. But if the allele confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. The process is self-reinforcing which means that an organism with an adaptive trait will survive and reproduce far more effectively than those with a maladaptive trait. The more offspring that an organism has the more fit it is that is determined by its capacity to reproduce itself and survive. Individuals with favorable characteristics, like having a longer neck in giraffes and bright white patterns of color in male peacocks are more likely to survive and have offspring, so they will make up the majority of the population over time.

Natural selection only affects populations, not individual organisms. This is a major distinction from the Lamarckian theory of evolution, which argues that animals acquire characteristics through use or neglect. If a giraffe extends its neck to reach prey, and the neck becomes longer, then the offspring will inherit this trait. The difference 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, alleles of a gene could reach different frequencies in a group due to random events. In the end, only one will be fixed (become common enough that it can no longer be eliminated by natural selection), and the rest of the alleles will diminish in frequency. This can lead to a dominant allele in extreme. The other alleles are basically eliminated and heterozygosity has decreased to a minimum. In a small population, this could result in the complete elimination of the recessive gene. This is known as the bottleneck effect. It is typical of the evolutionary process that occurs when a large number individuals migrate to form a group.

A phenotypic bottleneck may occur when survivors of a catastrophe, such as an epidemic or mass hunt, are confined in a limited area. The remaining individuals are likely to be homozygous for the dominant allele which means they will all have the same phenotype and will therefore share the same fitness characteristics. This could be caused by war, an earthquake or even a disease. Whatever the reason, the genetically distinct population that remains is susceptible to genetic drift.

Walsh Lewens, Walsh and Ariew define drift as a departure from expected values due to 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, whereas the other lives to reproduce.

This type of drift can play a crucial part in the evolution of an organism. This isn't the only method for evolution. The most common alternative is to use a process known as natural selection, in which the phenotypic diversity of the population is maintained through mutation and migration.

Stephens claims that there is a major distinction between treating drift as a force, or a cause and considering other causes of evolution, such as mutation, selection, and migration as forces or causes. He claims that a causal process explanation of drift allows us to distinguish it from these other forces, and this distinction is essential. He also argues that drift has a direction, that is it tends to reduce heterozygosity. He also claims that it also has a size, that is determined by the size of the population.

Evolution by Lamarckism

When high school students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is often known as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inheritance of traits that are a result of the natural activities of an organism, use and disuse. Lamarckism is illustrated through an giraffe's neck stretching to reach higher branches in the trees. This would result in giraffes passing on their longer necks to offspring, 에볼루션카지노 who then get taller.

Lamarck, a 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 the previous thinking on organic transformation. In his opinion living things had evolved from inanimate matter through an escalating series of steps. Lamarck wasn't the first to suggest this but he was considered to be the first to provide the subject a thorough and general overview.

The prevailing story is that Lamarckism became an opponent to Charles Darwin's theory of evolutionary natural selection, and that the two theories battled it out in the 19th century. Darwinism eventually won, leading to the development of what biologists now refer to as the Modern Synthesis. The theory argues that acquired traits can be passed down through generations and 에볼루션 사이트 바카라 (blaabjerg-rich-2.Technetbloggers.de) instead, it claims that organisms evolve through the selective action of environment factors, including Natural Selection.

While Lamarck supported the notion of inheritance through acquired characters and his contemporaries offered a few words about this idea, it was never a central element in any of their evolutionary theories. This is due in part to the fact that it was never tested scientifically.

It's been more than 200 years since Lamarck was born and in the age of genomics there is a huge body of evidence supporting the possibility of inheritance of acquired traits. This is referred to as "neo Lamarckism", or more commonly epigenetic inheritance. This is a model that is as reliable as the popular Neodarwinian model.

Evolution through Adaptation

One of the most commonly-held misconceptions about evolution is being driven by a fight for survival. This view is a misrepresentation of natural selection and ignores the other forces that drive evolution. The struggle for survival is more precisely described as a fight to survive within a specific environment, which can involve not only other organisms but as well the physical environment.

Understanding the concept of adaptation is crucial to understand evolution. It refers to a specific characteristic that allows an organism to live and reproduce within its environment. It can be a physiological structure like feathers or fur or a behavior such as a tendency to move to the shade during hot weather or coming out at night to avoid the cold.

The survival of an organism is dependent on its ability to extract energy from the environment and interact with other living organisms and their physical surroundings. The organism must have the right genes to generate offspring, and it should be able to locate sufficient food and other resources. The organism must also be able reproduce itself at the rate that is suitable for its particular niche.

These factors, together with gene flow and mutations can result in an alteration in the ratio of different alleles in the population's gene pool. Over time, this change in allele frequencies can lead to the emergence of new traits and eventually new species.

Many of the characteristics we admire about animals and plants are adaptations, for example, the lungs or gills that extract oxygen from the air, fur or feathers to protect themselves long legs to run away from predators and camouflage to hide. To comprehend adaptation it is crucial to distinguish between behavioral and physiological characteristics.

Physiological adaptations like the thick fur or gills are physical characteristics, whereas behavioral adaptations, like the desire to find friends or to move to the shade during hot weather, aren't. Furthermore it is important to remember that a lack of forethought is not a reason to make something an adaptation. A failure to consider the implications of a choice even if it appears to be rational, could make it inflexible.