Why All The Fuss? Free Evolution?

What is Free Evolution?

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

Many examples have been given of this, such as different kinds of stickleback fish that can live in either salt or fresh water, and walking stick insect varieties that prefer specific host plants. These are mostly reversible traits, however, cannot explain fundamental changes in basic 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.  similar site  is the best-established explanation. This is because individuals who are better-adapted survive and reproduce more 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 involves 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 within the species. Inheritance is the term used to describe the transmission of a person's genetic traits, including recessive and dominant genes to their offspring. Reproduction is the process of creating viable, fertile offspring. This can be accomplished by both asexual or sexual methods.

All of these factors must be in harmony to allow natural selection to take place. If, for example an allele of a dominant gene causes an organism reproduce and last longer than the recessive gene allele, then the dominant allele is more common in a population. However, if the gene confers an unfavorable survival advantage or decreases fertility, it will disappear from the population. This process is self-reinforcing, which means that the organism with an adaptive characteristic will live and reproduce far more effectively than one with a maladaptive characteristic. The more offspring that an organism has, the greater its fitness which is measured by its ability to reproduce and survive. People with good characteristics, like longer necks in giraffes or bright white patterns of color in male peacocks are more likely survive and produce offspring, and thus will become the majority of the population in the future.

Natural selection only acts on populations, not on individual organisms. This is an important distinction from the Lamarckian theory of evolution, which states that animals acquire characteristics through use or disuse. For example, if a Giraffe's neck grows longer due to stretching to reach for prey, its offspring will inherit a larger neck. The differences in neck size between generations will continue to increase until the giraffe is no longer able to breed with other giraffes.

Evolution through Genetic Drift

Genetic drift occurs when alleles from one gene are distributed randomly within a population. At some point, one will reach fixation (become so widespread that it can no longer be eliminated through natural selection), while other alleles fall to lower frequencies. In extreme cases this, it leads to a single allele dominance. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small population it could lead to the complete elimination of recessive allele. Such a scenario would be known as a bottleneck effect and it is typical of evolutionary process that occurs when a large number of people migrate to form a new population.

A phenotypic bottleneck can also happen when the survivors of a disaster such as an epidemic or mass hunting event, are concentrated into a small area. The remaining individuals will be mostly homozygous for the dominant allele meaning that they all share the same phenotype and will consequently have the same fitness traits. This can be caused by war, earthquakes, or even plagues. Whatever the reason the genetically distinct group that remains could be susceptible to genetic drift.

Walsh, Lewens, and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values of variations in fitness. They give the famous example of twins that are genetically identical and have exactly the same phenotype, but one is struck by lightning and dies, while the other is able to reproduce.

This kind of drift can play a significant role in the evolution of an organism. However, it is not the only method to develop. The most common alternative is a process called natural selection, in which phenotypic variation in the population is maintained through mutation and migration.

Stephens argues there is a vast difference between treating drift like an actual cause or force, and considering other causes, such as migration and selection as causes and forces. He claims that a causal process explanation of drift allows us to distinguish it from these other forces, and this distinction is crucial. He also argues that drift has a direction, that is it tends to reduce heterozygosity, and that it also has a magnitude, which is determined by the size of population.

Evolution through Lamarckism

In high school, students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is commonly called "Lamarckism" and it states that simple organisms develop into more complex organisms through the inheritance of characteristics that are a result of the natural activities of an organism, use and disuse. Lamarckism can be illustrated by a giraffe extending its neck to reach higher branches in the trees. This would cause giraffes to give their longer necks to their offspring, who would then become taller.

Lamarck the French Zoologist from France, presented a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged the traditional thinking about organic transformation. According to Lamarck, living creatures evolved from inanimate matter by a series of gradual steps. Lamarck was not the only one to suggest that this might be the case but he is widely seen as having given the subject his first comprehensive and comprehensive treatment.

The dominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were competing in the 19th Century. Darwinism eventually won and led to the creation of what biologists refer to as the Modern Synthesis. The theory denies that acquired characteristics can be passed down and instead argues organisms evolve by the selective influence of environmental factors, such as Natural Selection.

While Lamarck supported the notion of inheritance by acquired characters and his contemporaries also paid lip-service to this notion but it was not an integral part of any of their evolutionary theorizing. This is 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 age genomics, there is a growing evidence base that supports the heritability acquired characteristics. This is referred to as "neo Lamarckism", or more commonly epigenetic inheritance. This is a version that is just as valid as the popular Neodarwinian model.

Evolution by adaptation

One of the most commonly-held misconceptions about evolution is its being driven by a struggle to survive. This notion is not true and overlooks other forces that drive evolution. The fight for survival can be more accurately described as a struggle to survive within a specific environment, which can include not just other organisms but also the physical environment.

Understanding how adaptation works is essential to understand evolution. Adaptation refers to any particular feature that allows an organism to live and reproduce in its environment. It could be a physical structure like fur or feathers. Or it can be a behavior trait that allows you to move to the shade during hot weather or escaping the cold at night.

The survival of an organism is dependent on its ability to draw energy from the environment and to interact with other organisms and their physical environments. The organism must have the right genes to create offspring, and it should be able to access sufficient food and other resources. Furthermore, the organism needs to be able to reproduce itself at a high rate within its environment.

These factors, along with gene flow and mutation can result in an alteration in the percentage of alleles (different varieties of a particular 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 over time.

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

Physiological traits like the thick fur and gills are physical traits. The behavioral adaptations aren't like the tendency of animals to seek companionship or to retreat into the shade in hot weather. Additionally it is important to understand that lack of planning does not mean that something is an adaptation. A failure to consider the consequences of a decision even if it appears to be logical, can make it unadaptive.