10 Healthy Free Evolution Habits

What is Free Evolution?

Free evolution is the notion that natural processes can cause organisms to develop over time. This includes the appearance and growth of new species.

Numerous examples have been offered of this, including different kinds of stickleback fish that can live in either fresh or salt water and walking stick insect varieties that are attracted to particular host plants. These mostly reversible trait permutations, however, cannot explain fundamental changes in basic body plans.

Evolution by Natural Selection

The development of the myriad living organisms on Earth is a mystery that has intrigued scientists for many centuries. Charles Darwin's natural selectivity is the best-established explanation. This happens when those who are better adapted are able to reproduce faster and longer than those who are less well-adapted. As time passes, a group of well-adapted individuals expands and eventually becomes a new species.

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

Natural selection only occurs when all of these factors are in balance. For instance the case where the dominant allele of a gene allows an organism to live and reproduce more frequently than the recessive one, the dominant allele will become more prevalent in the population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will disappear. The process is self-reinforcing, meaning that a species with a beneficial characteristic can reproduce and survive longer than one with a maladaptive characteristic. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the greater number of offspring it can produce. Individuals with favorable characteristics, like longer necks in giraffes and bright white color patterns in male peacocks, are more likely to survive and produce offspring, and thus will become the majority of the population in the future.

Natural selection is a factor in populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution which argues that animals acquire characteristics through use or neglect. For example, if a giraffe's neck gets longer through stretching to reach for prey, its offspring will inherit a more long neck. The differences in neck size between generations will increase until the giraffe is no longer able to reproduce with other giraffes.

Read More Listed here through Genetic Drift

In genetic drift, alleles at a gene may be at different frequencies within a population due to random events. At some point, only one of them will be fixed (become common enough that it can no longer be eliminated by natural selection) and the other alleles will diminish in frequency. In the extreme this, it leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small group, this could lead to the total elimination of the recessive allele. This scenario is called the bottleneck effect and is typical of the evolutionary process that occurs whenever an enormous number of individuals move to form a group.

A phenotypic bottleneck can also occur when survivors of a catastrophe, such as an epidemic or mass hunt, are confined within a narrow area. The survivors will carry a dominant allele and thus will share the same phenotype. This could be the result of a war, an earthquake, or even a plague. Regardless of the cause the genetically distinct population that remains is prone to genetic drift.

Walsh Lewens and Ariew utilize a "purely outcome-oriented" definition of drift as any deviation from expected values for different fitness levels. They give a famous instance of twins who are genetically identical, have identical phenotypes, but one is struck by lightning and dies, while the other lives and reproduces.

This kind of drift can play a crucial role in the evolution of an organism. But, it's not the only way to progress. The main alternative is to use a process known as natural selection, in which the phenotypic diversity of the population is maintained through mutation and migration.

Stephens claims that there is a significant distinction between treating drift as a force or cause, and treating other causes such as migration and selection as causes and forces. He argues that a causal process explanation of drift allows us to distinguish it from the other forces, and this distinction is crucial. He argues further that drift has both an orientation, i.e., it tends to eliminate heterozygosity. It also has a size which is determined based on the size of the population.

Evolution by Lamarckism

Biology students in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution is often called "Lamarckism" and it asserts that simple organisms evolve into more complex organisms by the inheritance of traits that result from the natural activities of an organism usage, use and disuse. Lamarckism is typically illustrated by a picture of a giraffe that extends its neck longer to reach leaves higher up in the trees. This would cause giraffes to give their longer necks to offspring, which then become taller.

Lamarck, a French Zoologist from France, presented an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the previous thinking on organic transformation. According to Lamarck, living things evolved from inanimate material through a series of gradual steps. Lamarck was not the first to suggest that this could be the case, but the general consensus is that he was the one giving the subject its first general and comprehensive treatment.

The most popular story is that Lamarckism became an opponent to Charles Darwin's theory of evolution through natural selection, and that the two theories fought out in the 19th century. Darwinism eventually won and led to the development of what biologists today call the Modern Synthesis. This theory denies acquired characteristics can be passed down through generations and instead, it claims that organisms evolve through the selective action of environment factors, including Natural Selection.

Lamarck and his contemporaries supported the idea that acquired characters could be passed down to the next generation. However, this idea was never a key element of any of their theories on evolution. This is due in part 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 a growing body of evidence that supports the heritability acquired characteristics. This is referred to as "neo Lamarckism", or more generally epigenetic inheritance. This is a version that is as reliable as the popular Neodarwinian model.

Evolution through Adaptation

One of the most popular misconceptions about evolution is that it is a result of a kind of struggle for survival. This view misrepresents natural selection and ignores the other forces that drive evolution. The struggle for survival is more precisely described as a fight to survive in a specific environment, which could include not just other organisms but also the physical environment itself.

Understanding how adaptation works is essential to understand evolution. The term "adaptation" refers to any specific characteristic that allows an organism to live and reproduce in its environment. It could be a physiological feature, like feathers or fur or a behavior, such as moving into shade in hot weather or coming out at night to avoid cold.

The capacity of a living thing to extract energy from its surroundings and interact with other organisms, as well as their physical environment is essential to its survival. The organism must have the right genes to generate offspring, and must be able to find sufficient food and other resources. Moreover, the organism must be capable of reproducing itself at a high rate within its environment.

These elements, along with gene flow and mutations, can lead to changes in the proportion of different alleles in a population’s gene pool. As time passes, this shift in allele frequency can lead to the emergence of new traits, and eventually new species.

Many of the characteristics we admire in animals and plants are adaptations, like lung or gills for removing oxygen from the air, feathers or fur to provide insulation and long legs for running away from predators, and camouflage for hiding. To understand adaptation, it is important to differentiate between physiological and behavioral traits.

Physiological traits like thick fur and gills are physical characteristics. Behavioral adaptations are not, such as the tendency of animals to seek companionship or to retreat into the shade in hot temperatures. It is important to keep in mind that insufficient planning does not cause an adaptation. In fact, failing to think about the implications of a behavior can make it unadaptive even though it appears to be logical or even necessary.

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Pub: 24 Dec 2024 01:44 UTC
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