Free Evolution's History Of Free Evolution In 10 Milestones

What is Free Evolution?

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

This has been proven by numerous examples such as the stickleback fish species that can live in saltwater or fresh water and walking stick insect types that are apprehensive about specific host plants. These mostly reversible traits permutations do not explain the fundamental changes in the body's basic plans.

Evolution through Natural Selection

The evolution of the myriad living creatures on Earth is an enigma that has intrigued scientists for many centuries. Charles Darwin's natural selection theory is the best-established explanation. This is because those who are better adapted survive and reproduce more than those who are less well-adapted. As time passes, a group of well adapted individuals grows and eventually becomes a new species.

Natural selection is a cyclical process that involves the interaction of three elements: variation, inheritance and reproduction. Sexual reproduction and mutation increase genetic diversity in the species. Inheritance is the transfer of a person's genetic characteristics to their offspring, which includes both dominant and recessive alleles. Reproduction is the process of creating viable, fertile offspring. This can be done via sexual or asexual methods.

Natural selection is only possible when all these elements are in harmony. If, for instance, a dominant gene allele allows an organism to reproduce and last longer than the recessive gene allele, then the dominant allele is more prevalent in a population. However, if the gene confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. The process is self-reinforced, which means that an organism that has a beneficial trait will survive and reproduce more than one with an unadaptive characteristic. The higher the level of fitness an organism has, measured by its ability reproduce and endure, is the higher number of offspring it will produce. People with desirable traits, like longer necks 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 acts on populations, not individuals. This is an important distinction from the Lamarckian theory of evolution which states that animals acquire characteristics through use or disuse. For instance, if the Giraffe's neck grows longer due to reaching out to catch prey and its offspring will inherit a more long neck. The differences in neck size between generations will continue to grow until the giraffe becomes unable to breed with other giraffes.

Evolution by Genetic Drift

In genetic drift, the alleles of a gene could be at different frequencies in a group through random events. In the end, one will reach fixation (become so common that it cannot be removed through natural selection), while the other alleles drop to lower frequencies. In the extreme, this leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity decreases to zero. In a small group this could lead to the complete elimination the recessive gene. This scenario is called the bottleneck effect. It is typical of the evolutionary process that occurs when an enormous number of individuals move to form a group.

A phenotypic bottleneck can also occur when the survivors of a catastrophe such as an epidemic or a mass hunting event, are condensed in a limited area. The remaining individuals will be largely homozygous for the dominant allele, which means that they will all share the same phenotype, and consequently have the same fitness traits. This could be caused by a war, earthquake or even a disease. The genetically distinct population, if left, could be susceptible to genetic drift.

Walsh, Lewens, and Ariew utilize a "purely outcome-oriented" definition of drift as any departure from the expected values for variations in fitness. They cite a famous example of twins that are genetically identical, share the exact same phenotype but one is struck by lightning and dies, while the other lives and reproduces.

This kind of drift can be very important in the evolution of the species. This isn't the only method of evolution. Natural selection is the main alternative, in which mutations and migration keep the phenotypic diversity in the population.

Stephens argues there is a huge difference between treating drift like an actual cause or force, and considering other causes, such as migration and selection mutation as causes and forces. He claims that a causal-process explanation of drift lets us differentiate it from other forces and that this differentiation is crucial. He further argues that drift has a direction: that is, it tends to eliminate heterozygosity. It also has a magnitude, that is determined by population size.

에볼루션  by Lamarckism

Students of biology in high school are frequently exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution is often referred to as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inheritance of traits which result from an organism's natural activities, use and disuse. Lamarckism is typically illustrated by an image of a giraffe extending its neck further to reach the higher branches in the trees. This process would result in giraffes passing on their longer necks to offspring, who then get taller.

Lamarck was a French Zoologist. In his opening lecture for his course on invertebrate zoology held at the Museum of Natural History in Paris on the 17th May 1802, he presented an original idea that fundamentally challenged previous thinking about organic transformation. According Lamarck, living organisms evolved from inanimate material through a series gradual steps. Lamarck was not the first to suggest that this could be the case but the general consensus is that he was the one having given the subject his first comprehensive and comprehensive analysis.

The dominant story is that Charles Darwin's theory on natural selection and Lamarckism were rivals in the 19th Century. Darwinism eventually triumphed, leading to the development of what biologists call the Modern Synthesis. The theory denies that acquired characteristics are passed down from generation to generation and instead argues that organisms evolve through the selective action of environment factors, including Natural Selection.

Lamarck and his contemporaries supported the notion that acquired characters could be passed on to the next generation. However, this concept was never a major part of any of their evolutionary theories. This is largely due to the fact that it was never tested scientifically.

It has been more than 200 year since Lamarck's birth, and in the age genomics, there is an increasing evidence base that supports the heritability of acquired traits. It is sometimes called "neo-Lamarckism" or more commonly, epigenetic inheritance. This is a variant that is as reliable as the popular neodarwinian model.

Evolution through adaptation

One of the most popular misconceptions about evolution is that it is being driven by a fight for survival. In reality, this notion is inaccurate and overlooks the other forces that drive evolution. The fight for survival is better described as a struggle to survive in a particular environment. This can include not only other organisms but also the physical environment.

Understanding adaptation is important to understand evolution. It is a feature that allows a living thing to survive in its environment and reproduce. It could be a physiological structure such as feathers or fur or a behavior such as a tendency to move into the shade in hot weather or stepping out at night to avoid cold.

The ability of an organism to draw energy from its surroundings and interact with other organisms as well as their physical environments, is crucial to its survival. The organism should possess the right genes to produce offspring, and be able to find sufficient food and resources. Furthermore, the organism needs to be capable of reproducing at an optimal rate within its environmental niche.

These factors, together with mutation and gene flow result in an alteration in the percentage of alleles (different forms of a gene) in the gene pool of a population. The change in frequency of alleles can result in the emergence of new traits and eventually, new species as time passes.

A lot of the traits we admire about animals and plants are adaptations, such as the lungs or gills that extract oxygen from the air, fur or feathers for insulation long legs to run away from predators and camouflage to hide. However, a complete understanding of adaptation requires a keen eye to the distinction between the physiological and behavioral traits.

Physiological adaptations like thick fur or gills are physical traits, whereas behavioral adaptations, such as the tendency to seek out companions or to move to shade in hot weather, aren't. It is also important to note that lack of planning does not result in an adaptation. In fact, failure to think about the consequences of a behavior can make it unadaptive even though it appears to be logical or even necessary.