What is Free Evolution?

Free evolution is the notion that the natural processes that organisms go through can lead them to evolve over time. This includes the development 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 stickleback fish that can live in either salt or fresh water, as well as walking stick insect varieties that are attracted to particular host plants. These mostly reversible traits permutations do not explain the fundamental changes in the basic body plan.

Evolution by Natural Selection

The development of the myriad living organisms on Earth is a mystery that has intrigued scientists for centuries. Charles Darwin's natural selectivity is the most well-known explanation. This process occurs when people who are more well-adapted have more success in reproduction and survival than those who are less well-adapted. Over time, the population of well-adapted individuals becomes larger and eventually develops into an entirely new species.

Natural selection is an ongoing process that involves the interaction of three elements including inheritance, variation, and reproduction. Mutation and sexual reproduction increase the genetic diversity of a species. Inheritance refers to the passing of a person's genetic characteristics to the offspring of that person which includes both recessive and dominant alleles. Reproduction is the process of generating viable, fertile offspring. This can be done via sexual or asexual methods.

Natural selection only occurs when all these elements are in harmony. For example when a dominant allele at one gene can cause an organism to live and reproduce more often than the recessive allele, the dominant allele will become more prominent in the population. But if the allele confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. The process is self reinforcing, which means that an organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive trait. The higher the level of fitness an organism has which is measured by its ability to reproduce and survive, is the more offspring it can produce. People with good traits, like longer necks in giraffes or bright white colors in male peacocks are more likely be able to survive and create offspring, which means they will become the majority of the population over time.

Natural selection is an aspect of populations and not on individuals. This is an important distinction from the Lamarckian theory of evolution which states that animals acquire characteristics by use or inactivity. For example, if a Giraffe's neck grows longer due to stretching to reach for prey its offspring will inherit a more long neck. The differences in neck length between generations will continue until the giraffe's neck gets too long to not breed with other giraffes.

Evolution through Genetic Drift

In genetic drift, the alleles at a gene may be at different frequencies in a population by chance events. Eventually, only one will be fixed (become common enough to no longer be eliminated by natural selection), and the other alleles will drop in frequency. This can result in dominance in extreme. Other alleles have been basically eliminated and heterozygosity has diminished to a minimum. In a small population this could lead to the complete elimination the recessive gene. This scenario is known as a bottleneck effect and it is typical of evolutionary process that takes place when a large number of people migrate to form a new group.

A phenotypic bottleneck can also occur when the survivors of a disaster like an epidemic or a massive hunt, are confined in a limited area. The survivors will be mostly homozygous for the dominant allele, which means they will all share the same phenotype, and consequently share the same fitness characteristics. This could be caused by war, earthquakes or even a plague. The genetically distinct population, if it is left vulnerable to genetic drift.

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

This type of drift is crucial in the evolution of a species. It's not the only method for evolution. Natural selection is the main alternative, where mutations and migration maintain the phenotypic diversity of a population.

Stephens argues that there is a big difference between treating the phenomenon of drift as a force or a cause and considering other causes of evolution such as selection, mutation and migration as forces or causes. He claims that a causal process explanation of drift permits us to differentiate it from the other forces, and this distinction is vital. 에볼루션 블랙잭 Links to an external site. argues that drift is both a direction, i.e., it tends to reduce heterozygosity. It also has a size, that is determined by the size of the population.

Evolution through Lamarckism

When high school students study biology they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, often called "Lamarckism which means that simple organisms transform into more complex organisms through inheriting characteristics that are a product of the use and abuse of an organism. Lamarckism can be demonstrated by a giraffe extending its neck to reach higher branches in the trees. This would cause giraffes to give their longer necks to offspring, who would 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 the 17th May 1802, he introduced an original idea that fundamentally challenged the conventional wisdom about organic transformation. According to Lamarck, living things evolved from inanimate matter through a series of gradual steps. Lamarck was not the only one to suggest that this could be the case, but the general consensus is that he was the one giving the subject his first comprehensive and comprehensive analysis.

The most popular story is that Charles Darwin's theory of natural selection and Lamarckism were competing in the 19th Century. Darwinism ultimately prevailed and led to what biologists refer to as the Modern Synthesis. The theory argues that acquired traits can be passed down and instead argues organisms evolve by the influence of environment factors, including Natural Selection.

Lamarck and his contemporaries endorsed the idea that acquired characters could be passed down to the next generation. However, this notion was never a key element of any of their theories on evolution. This is partly because it was never scientifically validated.

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


Evolution through Adaptation

One of the most common misconceptions about evolution is that it is a result of a kind of struggle for survival. This notion is not true and ignores other forces driving evolution. The fight for survival can be better described as a fight to survive in a specific environment. This can include not only other organisms, but also the physical environment.

To understand how evolution operates it is important to think about what adaptation is. It refers to a specific characteristic that allows an organism to survive and reproduce in its environment. It can be a physical structure, such as feathers or fur. Or it can be a behavior trait, like moving to the shade during hot weather, or escaping the cold at night.

The survival of an organism is dependent on its ability to obtain energy from the surrounding environment and interact with other living organisms and their physical surroundings. The organism must have the right genes to produce offspring and to be able to access sufficient food and resources. The organism must be able to reproduce at a rate that is optimal for its niche.

These elements, in conjunction with mutation and gene flow result in a change in the proportion of alleles (different forms 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.

A lot of the traits we admire in animals and plants are adaptations, such as the lungs or gills that extract oxygen from the air, feathers or fur to provide insulation long legs to run away from predators, and camouflage for hiding. To understand adaptation, it is important to distinguish between behavioral and physiological characteristics.

Physiological traits like large gills and thick fur are physical traits. Behavioral adaptations are not, such as the tendency of animals to seek companionship or to retreat into the shade during hot temperatures. It is important to keep in mind that the absence of planning doesn't make an adaptation. A failure to consider the consequences of a decision, even if it appears to be rational, may make it inflexible.