15 Free Evolution Benefits Everyone Should Be Able To

What is Free Evolution?

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

A variety of examples have been provided of this, such as different varieties of stickleback fish that can live in either fresh or salt water and walking stick insect varieties that favor specific host plants. These typically reversible traits are not able to explain fundamental changes to basic body plans.

Evolution through Natural Selection

Scientists have been fascinated by the development of all the living creatures that inhabit our planet for centuries. The most well-known explanation is Charles Darwin's natural selection, a process that occurs when better-adapted individuals survive and reproduce more effectively than those who are less well adapted. Over time, a community of well adapted individuals grows and eventually forms a whole new species.

Natural selection is an ongoing process and involves the interaction of three factors that are: reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which increase the genetic diversity within an animal 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 producing fertile, viable offspring which includes both sexual and asexual methods.

All of these factors have to be in equilibrium for natural selection to occur. For example the case where the dominant allele of one gene causes an organism to survive and reproduce more frequently than the recessive allele, the dominant allele will become more prevalent within the population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will go away. This process is self-reinforcing meaning that an organism that has a beneficial trait can reproduce and survive longer than an individual with a maladaptive characteristic. The more offspring an organism can produce the more fit it is, which is measured by its ability to reproduce itself and survive. Individuals with favorable traits, such as having a longer neck in giraffes and bright white patterns of color in male peacocks, are more likely to survive and have offspring, so they will eventually make up the majority of the population in the future.

Natural selection only acts on populations, not individuals. This is an important distinction from the Lamarckian theory of evolution, which claims that animals acquire characteristics through use or neglect. If a giraffe extends its neck to catch prey, and the neck becomes longer, then the offspring will inherit this trait. The differences in neck size between generations will continue to increase until the giraffe is unable to breed with other giraffes.

Evolution by Genetic Drift

Genetic drift occurs when the alleles of one gene are distributed randomly in a group. In the end, one will reach fixation (become so common that it cannot be removed through natural selection) and the other alleles drop to lower frequency. This could lead to dominance in the extreme. Other alleles have been essentially eliminated and heterozygosity has decreased to zero. In a small number of people, this could result in the complete elimination of the recessive gene. 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 could occur when survivors of a catastrophe like an epidemic or mass hunting event, are condensed in a limited area. The remaining individuals will be largely homozygous for the dominant allele which means that they will all have the same phenotype and will therefore have the same fitness traits. This situation could be caused by war, earthquakes or even a plague. The genetically distinct population, if left susceptible to genetic drift.

Walsh Lewens, Walsh and Ariew define drift as a departure from the expected value due to differences in fitness. They provide a well-known example of twins that 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 be crucial in the evolution of the species. It is not the only method of evolution. The primary alternative is a process known as natural selection, where phenotypic variation in a population is maintained by mutation and migration.

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

Evolution by Lamarckism

Students of biology in high school are often exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution is commonly referred to as "Lamarckism" and it states that simple organisms grow into more complex organisms by the inherited characteristics which result from the organism's natural actions use and misuse. Lamarckism is illustrated through a giraffe extending its neck to reach higher branches in the trees. This could cause the necks of giraffes that are longer to be passed to their offspring, who would then become taller.

Lamarck was a French Zoologist. In his inaugural lecture for his course on invertebrate zoology held at the Museum of Natural History in Paris on the 17th of May in 1802, he introduced an innovative concept that completely challenged the previous understanding of organic transformation. According to Lamarck, living creatures evolved from inanimate material through a series gradual steps. Lamarck wasn't the first to propose this but he was considered to be the first to provide the subject a comprehensive and general treatment.

The most popular story is that Charles Darwin's theory on natural selection and Lamarckism were rivals in the 19th century. Darwinism eventually won and led to the creation of what biologists call the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead argues that organisms evolve through the selective action of environment elements, like Natural Selection.

Lamarck and his contemporaries believed in the idea that acquired characters could be passed down to future generations. However, this idea was never a key element of any of their theories about evolution. This is largely due to the fact that it was never tested scientifically.

It's been over 200 years since the birth of Lamarck and in the field of age genomics, there is a growing evidence-based body of evidence to support the heritability-acquired characteristics. This is also known as "neo Lamarckism", or more often epigenetic inheritance. It is a variant of evolution that is as relevant as the more popular neo-Darwinian model.

Evolution through Adaptation

One of the most widespread misconceptions about evolution is that it is a result of a kind of struggle to survive. This is a false assumption and overlooks other forces that drive evolution. The fight for survival can be better described as a struggle to survive in a specific environment. This may include not just other organisms as well as the physical surroundings themselves.

Understanding adaptation is important to comprehend evolution. It is a feature that allows a living thing to live in its environment and reproduce. It can be a physiological structure, such as fur or feathers, or a behavioral trait like moving into shade in the heat or leaving at night to avoid cold.

The survival of an organism is dependent on its ability to obtain energy from the environment and interact with other living organisms and their physical surroundings. The organism must possess the right genes to produce offspring, and be able to find sufficient food and 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 result in a change in the proportion of alleles (different varieties of a particular gene) in the gene pool of a population. Over time, this change in allele frequency can lead to the emergence of new traits and ultimately new species.

Many of the characteristics we admire in animals and plants are adaptations, like lungs or gills to extract oxygen from the air, feathers or fur to protect themselves and long legs for running away from predators and camouflage for hiding. However, a thorough understanding of adaptation requires paying attention to the distinction between the physiological and behavioral traits.

Physiological adaptations like thick fur or gills, are physical traits, while behavioral adaptations, such as the desire to find companions or to retreat to the shade during hot weather, are not. It is important to note that the absence of planning doesn't result in an adaptation. In fact, a failure to think about the implications of a choice can render it ineffective despite the fact that it might appear sensible or even necessary.

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Pub: 18 Dec 2024 23:04 UTC
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