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What is Free Evolution?

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

This has been demonstrated by many examples of stickleback fish species that can live in salt or fresh water, and walking stick insect species that have a preference for specific host plants. These typically reversible traits are not able to explain fundamental changes to basic body plans.

Evolution by Natural Selection

Scientists have been fascinated by the development of all living creatures that live on our planet for centuries. Charles Darwin's natural selectivity is the most well-known explanation. This process occurs when those who are better adapted have more success in reproduction and survival than those who are less well-adapted. As time passes, a group of well adapted individuals grows and eventually creates a new species.

Natural selection is a cyclical process that is characterized by the interaction of three elements that are inheritance, variation and reproduction. Sexual reproduction and mutation increase the genetic diversity of a species. Inheritance refers the transmission of a person's genetic traits, which include both dominant and recessive genes to their offspring. Reproduction is the process of generating fertile, viable offspring. This can be achieved through sexual or asexual methods.

???? ??? of these variables have to be in equilibrium to allow natural selection to take place. If, for example, a dominant gene allele causes an organism reproduce and survive more than the recessive allele, then the dominant allele will become more common in a population. However, if the gene confers a disadvantage in survival or reduces fertility, it will disappear from the population. This process is self-reinforcing meaning that a species with a beneficial characteristic is more likely to survive and reproduce than an individual with an inadaptive characteristic. The more offspring an organism produces the more fit it is which is measured by its ability to reproduce itself and live. People with desirable traits, like a long neck in giraffes, or bright white patterns on male peacocks, are more likely than others to reproduce and survive which eventually leads to them becoming the majority.

Natural selection is an element in the population and not on individuals. This is a major distinction from the Lamarckian theory of evolution which holds that animals acquire traits through usage or inaction. If a giraffe extends its neck in order to catch prey and its neck gets longer, then its children will inherit this characteristic. The length difference between generations will persist until the giraffe's neck becomes too 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 reach different frequencies in a group by chance events. In the end, one will reach fixation (become so common that it is unable to be removed by natural selection) and other alleles fall to lower frequencies. In extreme cases, this leads to one allele dominance. ???? ??? are essentially eliminated, and heterozygosity decreases to zero. In a small group it could lead to the total elimination of recessive allele. This scenario is called the bottleneck effect. It is typical of an evolution process that occurs when a large number individuals migrate to form a population.

A phenotypic bottleneck could occur when the survivors of a catastrophe such as an epidemic or a massive hunting event, are concentrated into a small area. The survivors will have an allele that is dominant and will share the same phenotype. This may be the result of a war, an earthquake or even a disease. The genetically distinct population, if it is left vulnerable to genetic drift.

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

This kind of drift can be vital to the evolution of a species. But, it's not the only way to develop. The most common alternative is a process called natural selection, where phenotypic variation in the population is maintained through mutation and migration.

Stephens asserts that there is a major distinction between treating drift as a force or an underlying cause, and considering other causes of evolution, such as mutation, selection, and migration as forces or causes. Stephens claims that a causal process explanation of drift lets us separate it from other forces and this differentiation is crucial. He also claims that drift has a direction: that is, it tends to eliminate heterozygosity, and that it also has a specific magnitude that is determined by the size of the population.

Evolution by 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 known as "Lamarckism" and it states that simple organisms grow into more complex organisms by the inherited characteristics that result from the organism's natural actions, use and disuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher levels of leaves in the trees. This causes giraffes' longer necks to be passed to their offspring, who would then become 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. According Lamarck, living organisms evolved from inanimate material by a series of gradual steps. Lamarck wasn't the first to propose this but he was regarded as the first to offer the subject a thorough and general overview.

The popular narrative is that Lamarckism became a rival to Charles Darwin's theory of evolution through natural selection, and both theories battled out in the 19th century. Darwinism ultimately won which led to what biologists refer to as the Modern Synthesis. This theory denies the possibility that acquired traits can be inherited and instead, it argues that organisms develop through the action of environmental factors, such as natural selection.

Lamarck and his contemporaries supported the idea that acquired characters could be passed down to the next generation. However, this concept was never a major part of any of their theories about evolution. This is partly 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 field of age genomics, there is an increasing evidence base that supports the heritability of acquired traits. This is also referred to as "neo Lamarckism", or more generally epigenetic inheritance. This is a model that is as reliable as the popular neodarwinian model.

Evolution by Adaptation

One of the most common misconceptions about evolution is that it is driven by a sort of struggle to survive. In fact, this view misrepresents natural selection and ignores the other forces that determine the rate of evolution. ???? ??? ??? for survival is more precisely described as a fight to survive within a particular environment, which may be a struggle that involves not only other organisms but as well the physical environment.

Understanding how adaptation works is essential to understand evolution. It refers to a specific feature that allows an organism to survive and reproduce in its environment. It can be a physiological structure, like feathers or fur or a behavior like moving into shade in hot weather or stepping out at night to avoid the cold.

The ability of an organism to extract energy from its environment and interact with other organisms and their physical environments, is crucial to its survival. The organism should possess the right genes to produce offspring and be able find enough food and resources. The organism should also be able to reproduce itself at the rate that is suitable for its specific niche.

These factors, together with gene flow and mutations can result in changes in the proportion of different alleles within the population's gene pool. As time passes, this shift in allele frequency can result in the emergence of new traits, and eventually new species.

Many of the features we find appealing in plants and animals are adaptations. For example the lungs or gills which extract oxygen from the air feathers and fur for insulation long legs to run away from predators, and camouflage to hide. However, a thorough understanding of adaptation requires a keen eye to the distinction between behavioral and physiological characteristics.

Physiological adaptations, such as thick fur or gills are physical traits, while behavioral adaptations, like the tendency to seek out friends or to move to shade in hot weather, are not. In addition it is important to note that lack of planning does not make something an adaptation. Inability to think about the consequences of a decision, even if it appears to be logical, can make it inflexible.

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