What is Free Evolution?

Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the creation of new species as well as the transformation of the appearance of existing ones.

A variety of examples have been provided of this, including various varieties of stickleback fish that can live in salt or fresh water, as well as walking stick insect varieties that favor specific host plants. These reversible traits, however, cannot explain fundamental changes in body plans.

Evolution by Natural Selection

Scientists have been fascinated by the evolution of all living creatures that inhabit our planet for ages. Charles Darwin's natural selection is the most well-known explanation. This happens when people who are more well-adapted have more success in reproduction and survival than those who are less well-adapted. As time passes, the number of well-adapted individuals grows and eventually creates an entirely new species.

Natural selection is an ongoing process that is characterized by the interaction of three elements that are inheritance, variation and reproduction. Variation is caused by mutations and sexual reproduction both of which increase the genetic diversity of the species. Inheritance refers the transmission of a person’s genetic traits, including both dominant and recessive genes and their offspring. Reproduction is the production of fertile, viable offspring which includes both asexual and sexual methods.

All of these variables must be in harmony to allow natural selection to take place. For instance, if the dominant allele of a gene causes an organism to survive and reproduce more often than the recessive allele the dominant allele will become more prevalent in the population. However, if the allele confers a disadvantage in survival or reduces fertility, it will be eliminated from the population. The process is self reinforcing meaning that the organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive trait. The more offspring an organism can produce the more fit it is that is determined by its ability to reproduce itself and live. Individuals with favorable traits, such as a longer neck in giraffes, or bright white colors in male peacocks are more likely to survive and produce offspring, and thus will make up the majority of the population over time.

Natural selection is an aspect of populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution, which states that animals acquire traits either through usage or inaction. For example, if a Giraffe's neck grows longer due to stretching to reach for prey, its offspring will inherit a larger neck. The difference in neck size between generations will continue to grow until the giraffe is unable to reproduce with other giraffes.

Evolution through Genetic Drift

Genetic drift occurs when alleles from one gene are distributed randomly in a population. At some point, one will reach fixation (become so common that it cannot be removed by natural selection) and other alleles fall to lower frequencies. This can lead to an allele that is dominant in the extreme. The other alleles are eliminated, and heterozygosity decreases to zero. In a small population this could result in the total elimination of recessive alleles. This is known as a bottleneck effect and it is typical of the kind of evolutionary process that occurs when a large number of individuals move to form a new group.

A phenotypic bottleneck can also occur when the survivors of a disaster like an outbreak or mass hunt incident are concentrated in an area of a limited size. The remaining individuals will be largely homozygous for the dominant allele, which means that they will all share the same phenotype and will therefore have the same fitness characteristics. This could be caused by earthquakes, war or even a plague. Whatever the reason the genetically distinct group that remains could be prone to genetic drift.

Walsh, Lewens and Ariew define drift as a departure from the expected value due to differences 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 is able to reproduce.

This kind of drift could play a significant part in the evolution of an organism. It's not the only method for evolution. The primary alternative is to use a process known as natural selection, where phenotypic variation in an individual is maintained through mutation and migration.

Stephens argues there is a significant difference between treating drift like a force or cause, and treating other causes like selection mutation and migration as forces and causes. He argues that a causal process explanation of drift allows us to distinguish it from other forces, and this distinction is crucial. He also argues that drift has both direction, i.e., it tends to eliminate heterozygosity. It also has a size which is determined based on 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 is generally called "Lamarckism" and it states that simple organisms develop into more complex organisms via the inheritance of traits that result from the natural activities of an organism use and misuse. https://alarmfriend1.bravejournal.net/how-much-do-evolution-free-baccarat-experts-make can be illustrated by the giraffe's neck being extended to reach higher levels of leaves in the trees. This could cause the necks of giraffes that are longer to be passed onto their offspring who would grow taller.

Lamarck was a French Zoologist. In his lecture to begin his course on invertebrate Zoology at the Museum of Natural History in Paris on the 17th May 1802, he presented an original idea that fundamentally challenged the conventional wisdom about organic transformation. According to Lamarck, living things evolved from inanimate materials by a series of gradual steps. Lamarck was not the first to suggest that this could be the case but he is widely seen as being the one who gave the subject its first broad and comprehensive analysis.

The most popular story is that Lamarckism grew into a rival to Charles Darwin's theory of evolution through natural selection and both theories battled each other in the 19th century. Darwinism ultimately prevailed, leading to what biologists refer to as the Modern Synthesis. This theory denies that acquired characteristics can be acquired through inheritance and instead, it argues that organisms develop by the symbiosis of environmental factors, like natural selection.

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

It's been more than 200 years since the birth of Lamarck, and in the age genomics, there is an increasing body of evidence that supports the heritability of acquired traits. This is also known as "neo Lamarckism", or more commonly epigenetic inheritance. It is a form of evolution that is as valid as the more well-known neo-Darwinian model.

Evolution by the process of adaptation

One of the most common misconceptions about evolution is that it is driven by a sort of struggle to survive. This view is inaccurate and overlooks the other forces that determine the rate of evolution. The fight for survival can be more effectively described as a struggle to survive within a particular environment, which can involve not only other organisms but also the physical environment itself.

To understand how evolution operates, it is helpful to consider what adaptation is. The term "adaptation" refers to any specific feature that allows an organism to survive and reproduce in its environment. It could be a physiological feature, like feathers or fur, or a behavioral trait, such as moving to the shade during hot weather or stepping out at night to avoid cold.

The capacity of an organism to draw energy from its environment and interact with other organisms and their physical environments, is crucial to its survival. The organism needs to have the right genes to create offspring, and it should be able to find sufficient food and other resources. Moreover, the organism must be capable of reproducing itself at a high rate within its niche.

These factors, along with gene flow and mutation can result in changes in the ratio of alleles (different forms of a gene) in the population's gene pool. Over time, this change in allele frequency can result in the development of new traits and eventually new species.

Many of the features that we admire about animals and plants are adaptations, such as lungs or gills to extract oxygen from the air, fur or feathers for insulation and long legs for running away from predators and camouflage for hiding. To understand the concept of adaptation it is essential to distinguish between behavioral and physiological traits.

Physiological traits like the thick fur and gills are physical characteristics. Behavior adaptations aren't, such as the tendency of animals to seek out companionship or retreat into shade in hot temperatures. Additionally, it is important to note that a lack of forethought is not a reason to make something an adaptation. Inability to think about the implications of a choice even if it appears to be logical, can make it unadaptive.