5 Must-Know Free Evolution-Practices You Need To Know For 2024

What is Free Evolution?

Free evolution is the idea that natural processes can lead to the development of organisms over time. This includes the appearance 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 varieties that prefer specific host plants. These are mostly reversible traits, however, cannot be the reason for fundamental changes in body plans.

Evolution through Natural Selection

The development of the myriad of living creatures on Earth is a mystery that has intrigued scientists for decades. The best-established explanation is Darwin's natural selection process, a process that occurs when individuals that are better adapted survive and reproduce more effectively than those that are less well adapted. As time passes, a group of well-adapted individuals expands and eventually creates a new species.

Natural selection is a cyclical process that is characterized by the interaction of three factors that are inheritance, variation and reproduction. Variation is caused by mutation and sexual reproduction, both of which increase the genetic diversity of an animal species. Inheritance is the passing of a person's genetic traits to their offspring which includes both recessive and dominant alleles. Reproduction is the process of creating viable, fertile offspring. This can be done through sexual or asexual methods.

All of these elements have to be in equilibrium for natural selection to occur. If, for instance an allele of a dominant gene causes an organism reproduce and live longer than the recessive gene then the dominant allele will become more common in a population. But if the allele confers an unfavorable survival advantage or reduces fertility, it will be eliminated from the population. The process is self-reinforced, which means that an organism with a beneficial trait will survive and reproduce more than one with a maladaptive trait. The more offspring that an organism has the more fit it is that is determined by its capacity to reproduce and survive. Individuals with favorable traits, like a longer neck in giraffes or bright white color patterns in male peacocks are more likely survive and produce offspring, so they will eventually make up the majority of the population in the future.

Natural selection is only an aspect of populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution that states that animals acquire traits through usage or inaction. If a giraffe stretches its neck in order to catch prey and the neck grows larger, then its offspring will inherit this trait. The differences in neck length between generations will continue until the giraffe's neck gets too long to not breed with other giraffes.

에볼루션 룰렛  by Genetic Drift

Genetic drift occurs when alleles of the same gene are randomly distributed in a group. Eventually, one of them will attain fixation (become so widespread that it cannot be eliminated by natural selection) and other alleles fall to lower frequencies. In the extreme, this leads to a single allele dominance. The other alleles are essentially eliminated, and heterozygosity decreases to zero. In a small group, this could lead to the total elimination of recessive alleles. Such a scenario would be called a bottleneck effect, and it is typical of evolutionary process that occurs when a large number of individuals migrate to form a new population.

A phenotypic  bottleneck may also occur when the survivors of a disaster like an outbreak or mass hunting event are confined to a small area. The survivors are likely to be homozygous for the dominant allele, meaning that they all share the same phenotype, and thus share the same fitness characteristics. This can be caused by earthquakes, war or even a plague. Regardless of the cause the genetically distinct population that remains could be susceptible to genetic drift.

Walsh Lewens, Lewens, and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values of differences in fitness. They give a famous instance of twins who are genetically identical and have identical phenotypes, and yet one is struck by lightning and dies, while the other lives and reproduces.

This type of drift is very important in the evolution of an entire species. It's not the only method for evolution. Natural selection is the primary alternative, in which mutations and migration maintain phenotypic diversity within the population.

Stephens argues there is a significant difference between treating the phenomenon of drift as an agent or cause and treating other causes like migration and selection as causes and forces. Stephens claims that a causal process account of drift allows 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 reduce heterozygosity. He also claims that it also has a specific magnitude that is determined by population size.

Evolution by Lamarckism

In high school, students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, commonly referred to as “Lamarckism” which means that simple organisms transform into more complex organisms through inheriting characteristics that result from the use and abuse of an organism. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher branches in the trees. This would cause giraffes' longer necks to be passed to their offspring, who would then become taller.

Lamarck the French zoologist, presented an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the conventional wisdom on 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 might 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 of natural selection and Lamarckism fought in the 19th century. Darwinism eventually won, leading to the development of what biologists now refer to as the Modern Synthesis. This theory denies acquired characteristics can be passed down through generations and instead, it claims that organisms evolve through the selective influence of environmental factors, including Natural Selection.

Although Lamarck supported the notion of inheritance by acquired characters, and his contemporaries also spoke of this idea but it was not a major feature in any of their evolutionary theories. This is due to the fact that it was never scientifically tested.

However, it has been more than 200 years since Lamarck was born and in the age genomics there is a vast amount of evidence to support the heritability of acquired traits. This is also known as "neo Lamarckism", or more generally epigenetic inheritance. This is a version that is just as valid as the popular Neodarwinian model.

Evolution by the process of adaptation

One of the most commonly-held misconceptions about evolution is its being driven by a struggle to survive. This view misrepresents natural selection and ignores the other forces that determine the rate of evolution. The fight for survival can be more accurately described as a struggle to survive in a specific environment, which may include not just other organisms but also the physical environment.

To understand how evolution works, it is helpful to consider what adaptation is. Adaptation refers to any particular characteristic that allows an organism to live and reproduce in its environment. It could be a physical feature, such as feathers or fur. Or it can be a trait of behavior that allows you to move towards shade during hot weather, or moving out to avoid the cold at night.

The capacity of an organism to extract energy from its environment and interact with other organisms, as well as their physical environment is essential to its survival. The organism needs to have the right genes to generate offspring, and it should be able to locate enough food and other resources. In addition, the organism should be able to reproduce itself at an optimal rate within its environment.

These elements, in conjunction with mutation and gene flow can result in a change in the proportion of alleles (different varieties of a particular gene) in the population's gene pool. This shift in the frequency of alleles can result in the emergence of novel traits and eventually new species as time passes.

A lot of the traits we appreciate in plants and animals are adaptations. For example lung or gills that extract oxygen from air, fur and feathers as insulation, long legs to run away from predators, and camouflage to hide. However, a proper understanding of adaptation requires a keen eye to the distinction between the physiological and behavioral characteristics.

Physiological traits like the thick fur and gills are physical traits. Behavior adaptations aren't, such as the tendency of animals to seek out companionship or to retreat into the shade during hot weather. Furthermore it is important to remember that lack of planning is not a reason to make something an adaptation. Inability to think about the effects of a behavior, even if it appears to be rational, could make it inflexible.