What is Free Evolution?

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

Many examples have been given of this, including different varieties of stickleback fish that can be found in fresh or salt water and walking stick insect varieties that prefer specific host plants. These reversible traits however, are not able to explain fundamental changes in body plans.

Evolution through Natural Selection

Scientists have been fascinated by the evolution of all the living creatures that live on our planet for centuries. The most well-known explanation is Darwin's natural selection, a process that occurs when individuals that are better adapted survive and reproduce more successfully than those who are less well-adapted. Over time, a community of well-adapted individuals expands and eventually forms a whole new species.

Natural selection is an ongoing process that is characterized by the interaction of three elements: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity of a species. Inheritance is the passing of a person's genetic characteristics to his or her offspring, which includes both dominant and recessive alleles. Reproduction is the process of producing fertile, viable offspring. This can be accomplished via sexual or asexual methods.

All of these factors must be in harmony for natural selection to occur. For instance when a dominant allele at the gene causes an organism to survive and reproduce more often than the recessive one, the dominant allele will become more prominent within the population. If the allele confers a negative survival advantage or decreases the fertility of the population, it will be eliminated. The process is self-reinforcing which means that an organism with an adaptive characteristic will live and reproduce more quickly than those with a maladaptive trait. The more offspring an organism can produce, the greater its fitness that is determined by its capacity to reproduce itself and live. People with desirable traits, such as having 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 make up the majority of the population in the future.

Natural selection is a factor in populations and not on individuals. This is an important distinction from the Lamarckian theory of evolution, which argues that animals acquire traits by use or inactivity. If a giraffe extends its neck to catch prey, and the neck becomes larger, then its children will inherit this characteristic. The differences in neck length between generations will persist until the neck of the giraffe becomes too long to not breed with other giraffes.

Evolution by Genetic Drift

In the process of genetic drift, alleles within a gene can be at different frequencies in a group by chance events. In the end, only one will be fixed (become widespread enough to not more be eliminated through natural selection), 에볼루션 블랙잭게이밍 (enquiry) and the other alleles decrease in frequency. In the extreme it can lead to a single allele dominance. The other alleles are eliminated, 에볼루션 게이밍 and heterozygosity is reduced to zero. In a small number of people, this could lead to the complete elimination of recessive alleles. This is known as the bottleneck effect. It is typical of the evolution process that occurs when the number of individuals migrate to form a population.

A phenotypic 'bottleneck' can also occur when the survivors of a catastrophe such as an outbreak or mass hunt event are concentrated in the same area. The surviving individuals are likely to be homozygous for the dominant allele which means that they will all share the same phenotype and will thus have the same fitness traits. This could be caused by a conflict, earthquake or even a cholera outbreak. Regardless of the cause, the genetically distinct population that is left might be prone to genetic drift.

Walsh Lewens, Walsh, and Ariew define drift as a deviation from the expected value due to differences in fitness. They provide the famous case of twins who are genetically identical and have exactly the same phenotype. However one is struck by lightning and 에볼루션 바카라 dies, but the other continues to reproduce.

This type of drift can play a significant role in the evolution of an organism. It's not the only method of evolution. The main alternative is to use a process known as natural selection, where phenotypic variation in an individual is maintained through mutation and migration.

Stephens claims that there is a huge difference between treating the phenomenon of drift as an actual cause or force, and considering other causes, such as migration and selection mutation as forces and causes. He argues that a causal-process model of drift allows us to distinguish it from other forces and that this distinction is essential. He also claims that drift has a direction: that is, it tends to eliminate heterozygosity. He also claims that it also has a specific magnitude which is determined by the size of population.

Evolution through Lamarckism

Biology students in high school are often introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution, also called "Lamarckism which means that simple organisms transform into more complex organisms by adopting traits that are a product of an organism's use and disuse. Lamarckism can be demonstrated by the giraffe's neck being extended to reach higher branches in the trees. This causes giraffes' longer necks to be passed onto their offspring who would grow taller.

Lamarck was a French zoologist and, in his inaugural lecture for his course on invertebrate zoology at the Museum of Natural History in Paris on the 17th of May in 1802, he presented an original idea that fundamentally challenged the previous understanding of organic transformation. According to Lamarck, living creatures evolved from inanimate matter through a series of gradual steps. Lamarck was not the only one to suggest that this might be the case, but the general consensus is that he was the one being the one who gave the subject its first general and thorough treatment.

The most popular story is that Lamarckism was an opponent to Charles Darwin's theory of evolutionary natural selection and that the two theories battled each other in the 19th century. Darwinism ultimately prevailed which led to what biologists refer to as the Modern Synthesis. The theory denies that acquired characteristics can be passed down through generations and instead, it claims that organisms evolve through the selective action of environment elements, like Natural Selection.

While Lamarck believed in the concept of inheritance by acquired characters and his contemporaries spoke of this idea however, it was not a major feature in any of their evolutionary theories. This is largely due to the fact that it was never validated scientifically.

It has been more than 200 year since Lamarck's birth and in the field of genomics there is a growing evidence base that supports the heritability-acquired characteristics. This is also known as "neo Lamarckism", or more generally epigenetic inheritance. This is a model that is as reliable 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. This notion is not true and overlooks other forces that drive evolution. The struggle for existence is better described as a fight to survive in a certain environment. This may include not only other organisms but also the physical environment.

To understand how evolution works, it is helpful to consider what adaptation is. Adaptation refers to any particular feature that allows an organism to survive and reproduce in its environment. It can be a physiological feature, such as fur or feathers, or a behavioral trait, such as moving into shade in hot weather or coming out at night to avoid the cold.

An organism's survival depends on its ability to draw energy from the environment and to interact with other living organisms and their physical surroundings. The organism must have the right genes for producing offspring and to be able to access enough food and resources. Furthermore, the organism needs to be capable of reproducing itself at an optimal rate within its environmental niche.

These factors, in conjunction with gene flow and mutations, can lead to a shift in the proportion of different alleles in the gene pool of a population. This shift in the frequency of alleles can result in the emergence of new traits, and eventually, new species as time passes.

A lot of the traits we find appealing in animals and plants are adaptations. For example lung or gills that draw oxygen from air feathers and fur for 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 the physiological and behavioral characteristics.

Physical traits such as large gills and thick fur are physical characteristics. Behavioral adaptations are not an exception, for instance, the tendency of animals to seek companionship or retreat into shade in hot weather. Additionally it is important to understand that lack of planning does not mean that something is an adaptation. In fact, failing to think about the consequences of a decision can render it unadaptive, despite the fact that it might appear reasonable or even essential.