This Is The Good And Bad About Free Evolution

What is Free Evolution?

Free evolution is the notion that the natural processes of living organisms can lead to their development over time. This includes the creation of new species as well as the alteration of the appearance of existing ones.

Numerous examples have been offered of this, such as different varieties of fish called sticklebacks that can live in either fresh or salt water and walking stick insect varieties that are attracted to particular host plants. These mostly reversible trait permutations can't, however, explain fundamental changes in basic body plans.

Evolution by Natural Selection

Scientists have been fascinated by the evolution of all the living organisms that inhabit our planet for centuries. Charles Darwin's natural selection is the best-established explanation. This process occurs when individuals who are better-adapted are able to reproduce faster and 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 cyclical process that involves the interaction of three elements: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which increase the genetic diversity of a species. Inheritance is the transfer of a person's genetic traits to the offspring of that person which includes both recessive and dominant alleles. Reproduction is the process of producing fertile, viable offspring, which includes both asexual and sexual methods.

All of these elements must be in harmony for natural selection to occur. If, for example the dominant gene allele makes an organism reproduce and survive more than the recessive gene allele, then the dominant allele will become more prevalent in a population. If the allele confers a negative advantage to survival or lowers the fertility of the population, it will be eliminated. This process is self-reinforcing which means that an organism with an adaptive trait will survive and reproduce much more than those with a maladaptive trait. The more offspring an organism produces the more fit it is, which is measured by its capacity to reproduce itself and survive. People with desirable traits, like a longer neck in giraffes or bright white patterns of color in male peacocks, are more likely to survive and produce offspring, and thus will eventually make up the majority of the population in the future.

Natural selection is an element in the population and not on individuals. This is an important distinction from the Lamarckian theory of evolution which argues that animals acquire traits through use or disuse. For instance, if a giraffe's neck gets longer through stretching to reach for prey and its offspring will inherit a larger 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

Genetic drift occurs when alleles from a gene are randomly distributed within a population. At some point, one will attain fixation (become so common that it can no longer be eliminated through natural selection), while other alleles will fall to lower frequencies. This can result in an allele that is dominant at the extreme. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small group, this could lead to the complete elimination of recessive allele. This scenario is called the bottleneck effect. It is typical of an evolutionary process that occurs whenever an enormous number of individuals move to form a population.

A phenotypic bottleneck may happen when the survivors of a disaster like an epidemic or a mass hunting event, are concentrated in a limited area. The survivors will carry a dominant allele and thus will have the same phenotype. This can be caused by earthquakes, war or even plagues. Regardless of the cause the genetically distinct population that remains is prone to genetic drift.

Walsh, Lewens and Ariew define drift as a deviation from the expected values due to differences in fitness. They provide the famous case of twins who are genetically identical and share the same phenotype, but one is struck by lightning and dies, whereas the other lives to reproduce.

This type of drift can play a crucial role in the evolution of an organism. However, it's not the only way to progress. The main alternative is to use a process known as natural selection, in which the phenotypic variation of a population is maintained by mutation and migration.

Stephens asserts that there is a significant difference 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 account of drift allows us differentiate it from other forces and this distinction is crucial. He further argues that drift is a directional force: that is, it tends to eliminate heterozygosity. He also claims that it also has a specific magnitude which is determined by population size.

Evolution by Lamarckism

Students of biology in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution, often called "Lamarckism which means that simple organisms transform into more complex organisms taking on traits that are a product of an organism's use and disuse. Lamarckism is illustrated through the giraffe's neck being extended to reach higher levels of leaves in the trees. This could result in giraffes passing on their longer necks to offspring, who then get taller.

Lamarck the French zoologist, presented a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged the traditional thinking about organic transformation. In his opinion living things had evolved from inanimate matter via a series of gradual steps. Lamarck wasn't the first to suggest this but he was thought of as the first to provide the subject a comprehensive and general overview.

The predominant story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were competing during the 19th century. Darwinism ultimately prevailed which led to what biologists refer to as the Modern Synthesis. The theory argues that traits acquired through evolution can be acquired through inheritance and instead argues that organisms evolve through the action of environmental factors, such as natural selection.

While Lamarck believed in the concept of inheritance by acquired characters and his contemporaries also paid lip-service to this notion but it was not a major feature in any of their evolutionary theories. This is due to the fact that it was never scientifically tested.

However, it has been more than 200 years since Lamarck was born and in the age of genomics there is a vast body of evidence supporting the heritability of acquired characteristics. It is sometimes referred to as "neo-Lamarckism" or, more commonly epigenetic inheritance. This is a version that is as valid as the popular neodarwinian model.

Evolution through the process of adaptation

One of the most popular misconceptions about evolution is that it is being driven by a struggle to survive. This is a false assumption and ignores other forces driving evolution. The struggle for survival is more accurately described as a struggle to survive in a specific environment, which could involve not only other organisms, but also the physical environment itself.

Understanding adaptation is important to comprehend evolution. The term "adaptation" refers to any specific characteristic that allows an organism to survive and reproduce in its environment. It could be a physiological feature, such as fur or feathers or a behavioral characteristic, such as moving into shade in hot weather or stepping out at night to avoid cold.

The capacity of an organism to draw energy from its environment and interact with other organisms, as well as their physical environment, is crucial to its survival. The organism needs to have the right genes to generate offspring, and must be able to find sufficient food and other resources. The organism should be able to reproduce itself at an amount that is appropriate for its particular niche.

These factors, together with gene flow and mutation can result in changes in the ratio of alleles (different forms of a gene) in the population's gene pool. This shift in the frequency of alleles can lead to the emergence of new traits, and eventually, new species as time passes.

A lot of the traits we appreciate in animals and plants are adaptations. For example lung or gills that draw oxygen from air, fur and feathers as insulation, long legs to run away from predators and camouflage to conceal. To comprehend adaptation it is crucial to discern between physiological and behavioral traits.

Physiological adaptations like the thick fur or gills are physical traits, while behavioral adaptations, like the tendency to search for companions or to move to the shade during hot weather, aren't. Additionally, it is important to understand that a lack of thought is not a reason to make something an adaptation. In  에볼루션 , a failure to consider the consequences of a decision can render it unadaptive even though it appears to be reasonable or even essential.