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What is Free Evolution?

Free evolution is the idea that the natural processes of living organisms can lead to their development over time. This includes the evolution of new species and the transformation of the appearance of existing ones.

Numerous examples have been offered of this, including different varieties of fish called sticklebacks that can be found in fresh or salt water and walking stick insect varieties that are attracted to particular host plants. These mostly reversible trait permutations, however, cannot be the reason for fundamental changes in body plans.

Evolution through Natural Selection

Scientists have been fascinated by the development of all the living creatures that live on our planet for centuries. Charles Darwin's natural selection theory is the most well-known explanation. This happens when those who are better adapted survive and reproduce more than those who are less well-adapted. Over time, a population of well-adapted individuals increases and eventually forms a whole new species.

Natural selection is an ongoing process and involves the interaction of three factors that are: reproduction, variation and inheritance. Variation is caused by mutations and sexual reproduction both of which increase the genetic diversity of the species. Inheritance refers to the passing of a person's genetic characteristics to his or her offspring that includes recessive and dominant alleles. Reproduction is the production of fertile, viable offspring which includes both sexual and asexual methods.

Natural selection can only occur when all of these factors are in balance. If, for instance the dominant gene allele causes an organism reproduce and survive more than the recessive allele then the dominant allele is more prevalent in a population. But if the allele confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. This process is self-reinforcing meaning that the organism with an adaptive characteristic will live and reproduce far more effectively than those with a maladaptive feature. The more offspring an organism can produce, the greater its fitness which is measured by its ability to reproduce itself and live. Individuals with favorable characteristics, such as a long neck in Giraffes, or the bright white color patterns on male peacocks are more likely to others to reproduce and survive and eventually lead to them becoming the majority.

Natural selection only affects populations, not on individuals. This is a significant distinction from the Lamarckian theory of evolution which holds that animals acquire traits through usage or inaction. If a giraffe expands its neck to reach prey and the neck grows longer, then its offspring will inherit this trait. The differences in neck size between generations will continue to grow until the giraffe is unable to reproduce with other giraffes.

Evolution by Genetic Drift

Genetic drift occurs when alleles from one gene are distributed randomly in a population. Eventually, only one will be fixed (become widespread enough to not longer be eliminated by natural selection) and the other alleles will diminish in frequency. In the extreme this, it leads to one allele dominance. The other alleles are eliminated, and heterozygosity falls to zero. In a small number of people it could lead to the complete elimination of recessive alleles. This is known as the bottleneck effect. It is typical of the evolutionary process that occurs when the number of individuals migrate to form a group.

A phenotypic bottleneck may occur when survivors of a disaster, such as an epidemic or mass hunt, are confined into a small area. The survivors will be mostly homozygous for the dominant allele, which means they will all have the same phenotype and therefore have the same fitness characteristics. This may be caused by conflict, earthquake or even a disease. The genetically distinct population, if it remains susceptible to genetic drift.

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

This kind of drift could play a significant part in the evolution of an organism. This isn't the only method of evolution. Natural selection is the primary alternative, where mutations and migration maintain phenotypic diversity within the population.

Stephens argues there is a vast difference between treating drift like a force or cause, and treating other causes such as migration and selection mutation as causes and forces. He claims that a causal-process account of drift allows us differentiate it from other forces, and this distinction is essential. He also argues that drift has both direction, i.e., it tends to reduce heterozygosity. It also has a size which is determined based on the size of the population.

Evolution by Lamarckism

Students of biology in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is often referred to as "Lamarckism" and it asserts that simple organisms evolve into more complex organisms through the inheritance of characteristics that are a result of the natural activities of an organism use and misuse. Lamarckism can be illustrated by a giraffe extending its neck to reach higher leaves in the trees. This could result in giraffes passing on their longer necks to their offspring, who would then get taller.

Lamarck Lamarck, a French zoologist, presented an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on organic transformation. According to him living things had evolved from inanimate matter through a series of gradual steps. Lamarck wasn't the first to suggest this however he was widely regarded as the first to offer the subject a comprehensive and general overview.

The most popular story is that Charles Darwin's theory of natural selection and Lamarckism fought in the 19th Century. Darwinism eventually triumphed and led to the creation of what biologists today call the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead argues organisms evolve by the influence of environment factors, including Natural Selection.

Although Lamarck supported the notion of inheritance through acquired characters, and his contemporaries also paid lip-service to this notion but it was not a major feature in any of their theories about evolution. This is partly due to the fact that it was never tested scientifically.

It's been over 200 years since the birth of Lamarck and in the field of genomics, there is a growing evidence-based body of evidence to support the heritability acquired characteristics. This is also referred to as "neo Lamarckism", or more often epigenetic inheritance. This is a version that is just as valid as the popular Neodarwinian model.

Evolution KR through Adaptation

One of the most commonly-held misconceptions about evolution is being driven by a struggle for survival. This view is inaccurate and overlooks other forces that drive evolution. The fight for survival can be better described as a fight to survive in a particular environment. This can include not just other organisms as well as the physical environment itself.

Understanding the concept of adaptation is crucial to understand evolution. Adaptation is any feature that allows a living thing to live in its environment and reproduce. It could be a physical feature, such as feathers or fur. It could also be a characteristic of behavior that allows you to move into the shade during hot weather or moving out to avoid the cold at night.

The capacity of a living thing to extract energy from its environment and interact with other organisms and their physical environment is essential to its survival. The organism must have the right genes to produce offspring and to be able to access enough food and resources. The organism should be able to reproduce itself at an amount that is appropriate for its niche.

These elements, in conjunction with gene flow and mutation can result in a change in the proportion of alleles (different forms of a gene) in a population's gene pool. Over time, this change in allele frequency can result in the emergence of new traits and eventually new species.

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

Physical traits such as large gills and thick fur are physical characteristics. The behavioral adaptations aren't an exception, for instance, the tendency of animals to seek companionship or retreat into shade during hot temperatures. Furthermore, it is important to understand that a lack of thought does not mean that something is an adaptation. In fact, failing to consider the consequences of a decision can render it unadaptive even though it might appear logical or even necessary.