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What is Free Evolution?


Free evolution is the idea that natural processes can lead to the development of organisms over time. This includes the emergence and development of new species.

Numerous examples have been offered of this, such as different varieties of fish called sticklebacks that can be found in salt or fresh water, as well as walking stick insect varieties that are attracted to specific host plants. These reversible traits however, are not able to explain fundamental changes in basic body plans.

Evolution by Natural Selection

Scientists have been fascinated by the evolution of all living creatures that inhabit our planet for ages. The most widely accepted explanation is that of Charles Darwin's natural selection process, a process that occurs when better-adapted individuals survive and reproduce more effectively than those that are less well-adapted. Over time, the population of individuals who are well-adapted grows and eventually creates a new species.

Natural selection is an ongoing process that is characterized by the interaction of three elements: variation, inheritance and reproduction. Mutation and sexual reproduction increase the genetic diversity of an animal species. Inheritance is the term used to describe the transmission of a person’s genetic traits, including both dominant and recessive genes, to their offspring. Reproduction is the process of generating fertile, viable offspring. This can be achieved through sexual or asexual methods.

All of these elements must be in harmony to allow natural selection to take place. If, for instance an allele of a dominant gene makes an organism reproduce and last longer than the recessive allele The dominant allele becomes more prevalent in a population. If the allele confers a negative advantage to survival or reduces the fertility of the population, it will go away. This process is self-reinforcing meaning that a species with a beneficial trait is more likely to survive and reproduce than an individual with a maladaptive characteristic. The more fit an organism is, measured by its ability reproduce and endure, is the higher number of offspring it produces. People with desirable traits, like a longer neck in giraffes, or bright white color patterns in male peacocks are more likely to survive and have offspring, so they will make up the majority of the population in the future.

Natural selection is only an element in the population and not on individuals. This is a major distinction from the Lamarckian theory of evolution, which states that animals acquire traits due to use or lack of use. For instance, if a animal's neck is lengthened by reaching out to catch prey and its offspring will inherit a larger neck. The differences in neck length between generations will persist until the giraffe's neck gets too long to not breed with other giraffes.

Evolution by Genetic Drift

Genetic drift occurs when the alleles of the same gene are randomly distributed within a population. At some point, one will reach fixation (become so widespread that it is unable to be eliminated through natural selection), while other alleles fall to lower frequencies. This could lead to dominance at the extreme. The other alleles have been essentially eliminated and heterozygosity has been reduced to zero. In talks about it , this could result in the complete elimination of recessive gene. This scenario is called the bottleneck effect. It is typical of an evolutionary process that occurs whenever the number of individuals migrate to form a population.

A phenotypic bottleneck may also occur when the survivors of a catastrophe like an outbreak or a mass hunting event are concentrated in an area of a limited size. The survivors will carry an allele that is dominant and will share the same phenotype. This could be caused by 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, and Ariew use a "purely outcome-oriented" definition of drift as any departure from the expected values for differences in fitness. They provide the famous case of twins that are genetically identical and share the same phenotype. However one is struck by lightning and dies, but the other lives to reproduce.

This kind of drift could be very important in the evolution of the species. It is not the only method for evolution. Natural selection is the primary alternative, where mutations and migration maintain the phenotypic diversity of the population.

Stephens claims that there is a significant difference between treating the phenomenon of drift as a force or cause, and treating other causes like migration and selection as causes and forces. He argues that a causal-process account of drift allows us differentiate it from other forces and that this distinction is crucial. He also argues that drift has a direction, that is it tends to reduce heterozygosity, and that it also has a size, which is determined by the size of population.

Evolution through Lamarckism

In high school, students study biology they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is often referred to as "Lamarckism" and it asserts that simple organisms evolve into more complex organisms through the inherited characteristics which result from the organism's natural actions, use and disuse. Lamarckism can be illustrated by an giraffe's neck stretching to reach higher levels of leaves in the trees. This process would cause giraffes to pass on their longer necks to their offspring, who then get taller.

Lamarck was a French Zoologist. In his opening lecture for his course on invertebrate Zoology at the Museum of Natural History in Paris on 17 May 1802, he presented a groundbreaking concept that radically challenged previous thinking about organic transformation. According to him, living things had evolved from inanimate matter via the gradual progression of events. Lamarck was not the only one to suggest that this could be the case but his reputation is widely regarded as giving the subject its first broad and comprehensive analysis.

The dominant story is that Charles Darwin's theory of natural selection and Lamarckism were rivals during the 19th century. Darwinism ultimately won which led to what biologists refer to as the Modern Synthesis. The Modern Synthesis theory denies that acquired characteristics can be inherited, and instead argues that organisms evolve by the symbiosis of environmental factors, like natural selection.

Lamarck and his contemporaries supported the idea that acquired characters could be passed down to future generations. However, this notion was never a key element of any of their theories about evolution. This is partly 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 an increasing body of evidence that supports the heritability of acquired traits. This is sometimes called "neo-Lamarckism" or, more often, epigenetic inheritance. It is a form of evolution that is as relevant as the more popular neo-Darwinian model.

Evolution by adaptation

One of the most popular misconceptions about evolution is being driven by a fight for survival. This notion is not true and ignores other forces driving evolution. The fight for survival is better described as a fight to survive in a specific environment. This may include not only other organisms as well as the physical environment itself.

Understanding adaptation is important to understand evolution. Adaptation refers to any particular characteristic that allows an organism to survive and reproduce in its environment. It can be a physiological feature, like feathers or fur or a behavioral characteristic, such as moving to the shade during hot weather or stepping out at night to avoid cold.

The survival of an organism depends on its ability to obtain energy from the environment and to interact with other organisms and their physical environments. The organism must possess the right genes to create offspring, and it must be able to locate enough food and other resources. Moreover, the organism must be capable of reproducing in a way that is optimally within its niche.

These factors, along with gene flow and mutation, lead to a change in the proportion of alleles (different types of a gene) in the gene pool of a population. Over time, this change in allele frequencies can result in the emergence of new traits and ultimately new species.

Many of the characteristics we find appealing in animals and plants are adaptations. For instance, lungs or gills that draw oxygen from air feathers and fur for insulation, long legs to run away from predators and camouflage to conceal. To understand the concept of adaptation it is crucial to differentiate between physiological and behavioral characteristics.

Physiological traits like the thick fur and gills are physical traits. The behavioral adaptations aren't an exception, for instance, the tendency of animals to seek out companionship or retreat into shade during hot weather. Additionally, it is important to remember that a lack of thought does not make something an adaptation. A failure to consider the consequences of a decision even if it seems to be rational, could make it unadaptive.

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