What is Free Evolution?

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

Numerous examples have been offered of this, including various varieties of fish called sticklebacks that can live in salt or fresh water, as well as walking stick insect varieties that are attracted to specific host plants. These reversible traits can't, however, explain fundamental changes in basic body plans.

Evolution by Natural Selection

Scientists have been fascinated by the development of all living creatures that inhabit our planet for many centuries. Charles Darwin's natural selection is the best-established explanation. This is because people who are more well-adapted survive and reproduce more than those who are less well-adapted. As time passes, the number of well-adapted individuals grows and eventually develops into an entirely new species.

Natural selection is an ongoing process and involves the interaction of 3 factors that are: reproduction, variation and inheritance. Variation is caused by mutations and sexual reproduction both of which increase the genetic diversity within a species. Inheritance refers to the transmission of a person’s genetic traits, which include recessive and dominant genes to their offspring. Reproduction is the generation of fertile, viable offspring, which includes both sexual and asexual methods.

All of these factors have to be in equilibrium for natural selection to occur. For instance the case where an allele that is dominant at the gene causes an organism to survive and reproduce more often than the recessive allele the dominant allele will be more prominent within the population. However, if the gene confers a disadvantage in survival or reduces fertility, it will disappear from the population. The process is self-reinforcing, which means that an organism that has a beneficial trait is more likely to survive and reproduce than an individual with an unadaptive trait. The more offspring an organism can produce the more fit it is which is measured by its capacity to reproduce itself and survive. People with desirable traits, like longer necks in giraffes or bright white patterns of color in male peacocks are more likely to be able to survive and create offspring, so they will become the majority of the population over time.

Natural selection is a factor in 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. If a giraffe extends its neck to catch prey, and the neck becomes longer, then its offspring will inherit this trait. The difference in neck length between generations will persist until the giraffe's neck becomes so long that it can no longer breed with other giraffes.

Evolution by Genetic Drift

In the process of genetic drift, alleles at a gene may attain different frequencies within a population due to random events. At some point, one will attain fixation (become so widespread that it can no longer be removed through natural selection) and other alleles will fall to lower frequencies. This can result in an allele that is dominant at the extreme. The other alleles are eliminated, and heterozygosity decreases to zero. In a small number of people it could lead to the complete elimination of the recessive allele. This is known as the bottleneck effect and is typical of an evolutionary process that occurs whenever an enormous number of individuals move 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 a small area. The survivors are likely to be homozygous for the dominant allele meaning that they all have the same phenotype and will thus have the same fitness traits. This situation might be the result of a conflict, earthquake or even a disease. The genetically distinct population, if it remains susceptible to genetic drift.

Walsh Lewens and Ariew utilize a "purely outcome-oriented" definition of drift as any deviation from the expected values for variations in fitness. They cite the famous example of twins who are genetically identical and have exactly 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 most common alternative, in which mutations and migration maintain phenotypic diversity within the population.

Stephens asserts that there is a vast distinction between treating drift as an actual cause or force, and treating other causes like selection mutation and migration as causes and forces. Stephens claims that a causal process explanation of drift lets us separate it from other forces and this differentiation is crucial. He argues further that drift is both an orientation, 에볼루션 i.e., it tends to eliminate heterozygosity. It also has a size, that is determined by population size.

Evolution by Lamarckism

Biology students in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is commonly referred to as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inherited characteristics that are a result of an organism's natural activities, use and disuse. Lamarckism can be illustrated by a giraffe extending its neck to reach higher branches in the trees. This could cause the necks of giraffes that are longer to be passed to their offspring, who would grow taller.

Lamarck, a French Zoologist, introduced a revolutionary concept in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on organic transformation. In his opinion living things evolved from inanimate matter via an escalating series of steps. Lamarck was not the first to suggest that this could be the case but he is widely seen as having given the subject his first comprehensive and thorough treatment.

The popular narrative is that Lamarckism became an opponent to Charles Darwin's theory of evolutionary natural selection and that the two theories fought out in the 19th century. Darwinism eventually won, leading to the development of what biologists now refer to as the Modern Synthesis. This theory denies the possibility that acquired traits can be acquired through inheritance and instead, it argues that organisms develop through the selective action of environmental factors, like natural selection.

Lamarck and his contemporaries endorsed the idea that acquired characters could be passed on to future generations. However, this concept was never a major part of any of their theories on evolution. This is partly due to the fact that it was never tested scientifically.

It's been more than 200 years since the birth of Lamarck and in the field of genomics, there is an increasing evidence-based body of evidence to support the heritability acquired characteristics. This is also referred to as "neo Lamarckism", or more generally epigenetic inheritance. It is a variant of evolution that is as valid as the more popular Neo-Darwinian theory.

Evolution by the process of adaptation

One of the most common misconceptions about evolution is that it is driven by a sort of struggle for survival. This notion is not true and ignores other forces driving evolution. The fight for survival can be more precisely described as a fight to survive within a specific environment, which could be a struggle that involves not only other organisms, but also the physical environment itself.

To understand how evolution functions it is important to understand what is adaptation. Adaptation is any feature that allows a living thing to survive in its environment and reproduce. It can be a physiological structure like feathers or fur or a behavioral characteristic, such as moving into the shade in the heat or leaving at night to avoid the cold.

The capacity of an organism to draw energy from its surroundings and interact with other organisms and their physical environments is essential to its survival. The organism must possess the right genes to generate offspring, and it must be able to locate enough food and other resources. The organism should also be able to reproduce at a rate that is optimal for its niche.

These elements, in conjunction with mutation and gene flow result in an alteration in the percentage of alleles (different varieties of a particular gene) in the population's gene pool. Over time, this change in allele frequencies could result in the emergence of new traits and ultimately new species.

A lot of the traits we appreciate in animals and plants are adaptations. For instance the lungs or gills which extract oxygen from air, fur and feathers as insulation and long legs to get away from predators and camouflage to conceal. However, a proper understanding of adaptation requires attention to the distinction between physiological and behavioral traits.

Physical characteristics like thick fur and gills are physical traits. Behavior adaptations aren't like the tendency of animals to seek out companionship or to retreat into the shade during hot temperatures. It is important to keep in mind that insufficient planning does not result in an adaptation. Failure to consider the implications of a choice even if it seems to be logical, can make it unadaptive.