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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 development of new species and the transformation of the appearance of existing species.

A variety of examples have been provided of this, including different kinds of stickleback fish that can live in either salt or fresh water, as well as walking stick insect varieties that are attracted to specific host plants. These mostly reversible traits permutations are not able to explain fundamental changes to the basic body plan.

Evolution through Natural Selection

Scientists have been fascinated by the evolution of all living creatures that inhabit our planet for ages. The best-established explanation is Darwin's natural selection, which occurs when better-adapted individuals survive and reproduce more successfully than those less well-adapted. Over time, a population of well adapted individuals grows and eventually forms a whole new species.

Natural selection is a process that is cyclical and involves the interaction of three factors that are: reproduction, variation and inheritance. Mutation and sexual reproduction increase genetic diversity in a species. Inheritance refers to the passing of a person's genetic traits to the offspring of that person, which includes both recessive and dominant alleles. Reproduction is the process of creating fertile, viable offspring. This can be done via sexual or asexual methods.

All of these factors have to be in equilibrium to allow natural selection to take place. If, for example, a dominant gene allele causes an organism reproduce and last longer than the recessive gene then the dominant allele will become more prevalent 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, which means that the organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive trait. The more offspring an organism produces, the greater its fitness which is measured by its capacity to reproduce itself and live. Individuals with favorable traits, like having a long neck in giraffes, or bright white color patterns on male peacocks are more likely than others to reproduce and survive, which will eventually lead to them becoming the majority.

Natural selection only affects populations, not on individuals. This is a major distinction from the Lamarckian evolution theory that states that animals acquire traits due to usage or inaction. For instance, if the animal's neck is lengthened by stretching to reach prey and its offspring will inherit a larger neck. The difference in neck length between generations will persist until the giraffe's neck gets too long that it can no longer breed with other giraffes.

Evolution through Genetic Drift

Genetic drift occurs when alleles of a gene are randomly distributed in a group. Eventually, only one will be fixed (become widespread enough to not more be eliminated through natural selection), and the other alleles decrease in frequency. In extreme cases this, it leads to one allele dominance. The other alleles are virtually eliminated and heterozygosity decreased to a minimum. In a small number of people this could result in the total elimination of recessive alleles. This is known as the bottleneck effect and is typical of an evolution process that occurs when an enormous number of individuals move to form a group.

A phenotypic bottleneck may also occur when survivors of a disaster such as an outbreak or a mass hunting event are concentrated in the same area. The remaining individuals will be mostly homozygous for the dominant allele, which means they will all have the same phenotype, and thus have the same fitness characteristics. This could be caused by war, earthquakes, or even plagues. The genetically distinct population, if left susceptible to genetic drift.

Walsh, Lewens and Ariew define drift as a deviation from the expected value due to differences in fitness. They provide the famous case of twins who are genetically identical and share the same phenotype. However one is struck by lightning and dies, but the other lives to reproduce.

This kind of drift could play a very important part in the evolution of an organism. It's not the only method for evolution. The main alternative is a process known as natural selection, in which the phenotypic diversity of an individual is maintained through mutation and migration.

Stephens claims that there is a significant difference between treating drift like an agent or cause and treating other causes such as migration and selection as forces and causes. He argues that a causal-process account of drift allows us distinguish it from other forces and this differentiation is crucial. He also claims that drift is a directional force: that is it tends to eliminate heterozygosity, and that it also has a specific magnitude that is determined by population size.

Evolution through Lamarckism

When students in high school take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, commonly called "Lamarckism which means that simple organisms transform into more complex organisms taking on traits that are a product of the use and abuse of an organism. Lamarckism is usually illustrated with an image of a giraffe stretching its neck to reach the higher branches in the trees. This would result in giraffes passing on their longer necks to offspring, which then grow even taller.


Lamarck Lamarck, a French zoologist, presented an idea that was revolutionary in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. According sell , living organisms evolved from inanimate material by a series of gradual steps. Lamarck was not the first to suggest that this might be the case but he is widely seen as being the one who gave the subject its first broad and thorough treatment.

The most popular story is that Lamarckism was an opponent to Charles Darwin's theory of evolutionary natural selection, and that the two theories fought out in the 19th century. Darwinism ultimately prevailed, leading to what biologists call the Modern Synthesis. The Modern Synthesis theory denies the possibility that acquired traits can be acquired through inheritance and instead suggests that organisms evolve through the action of environmental factors, such as natural selection.

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

But it is now more than 200 years since Lamarck was born and, in the age of genomics there is a huge amount of evidence to support the possibility of inheritance of acquired traits. This is sometimes called "neo-Lamarckism" or, more often, 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 commonly-held misconceptions about evolution is that it is being driven by a struggle to survive. This notion is not true and ignores other forces driving evolution. The struggle for survival is more accurately described as a struggle to survive within a particular environment, which may include not just other organisms, but also the physical environment.

To understand how evolution functions, it is helpful to consider what adaptation is. It is a feature that allows a living thing to live in its environment and reproduce. It can be a physical feature, such as feathers or fur. It could also be a behavior trait that allows you to move to the shade during hot weather, or moving out to avoid the cold at night.

An organism's survival depends on its ability to draw energy from the environment and to interact with other organisms and their physical environments. The organism should possess the right genes to produce offspring and to be able to access sufficient food and resources. The organism must be able to reproduce at a rate that is optimal for its specific niche.

These elements, in conjunction 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. As time passes, this shift in allele frequencies could result in the emergence of new traits and ultimately new species.

A lot of the traits we admire in plants and animals are adaptations. For instance the lungs or gills which extract oxygen from air feathers and fur as insulation, long legs to run away from predators and camouflage for hiding. To understand adaptation it is essential to discern between physiological and behavioral traits.

Physical traits such as thick fur and gills are physical characteristics. Behavior adaptations aren't an exception, for instance, the tendency of animals to seek out companionship or to retreat into the shade during hot temperatures. It is important to remember that a insufficient planning does not make an adaptation. In fact, failure to consider the consequences of a behavior can make it unadaptable even though it might appear sensible or even necessary.

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