7 Things You Didn't Know About Free Evolution
What is Free Evolution?
Free evolution is the concept that the natural processes that organisms go through can lead them to evolve over time. This includes the appearance and development of new species.
A variety of examples have been provided of this, such as different kinds of stickleback fish that can live in salt or fresh water, as well as walking stick insect varieties that favor particular host plants. These reversible traits cannot explain fundamental changes to the body's basic plans.
Evolution by Natural Selection
The evolution of the myriad living organisms on Earth is a mystery that has intrigued scientists for centuries. Charles Darwin's natural selectivity is the best-established explanation. This is because those who are better adapted are able to reproduce faster and longer than those who are less well-adapted. As time passes, the number of well-adapted individuals grows and eventually forms an entirely new species.
Natural selection is an ongoing process and involves the interaction of 3 factors: variation, reproduction and inheritance. Mutation and sexual reproduction increase genetic diversity in the species. Inheritance refers to the passing of a person's genetic characteristics to his or her offspring, which includes both recessive and dominant alleles. Reproduction is the process of producing viable, fertile offspring, which includes both asexual and sexual methods.
Natural selection is only possible when all these elements are in harmony. For example, if an allele that is dominant at the gene can cause an organism to live and reproduce more often than the recessive allele the dominant allele will be more prevalent within the population. However, if the gene confers an unfavorable survival advantage or reduces fertility, it will disappear from the population. This process is self-reinforcing which means that an organism with a beneficial characteristic can reproduce and survive longer than one with an inadaptive characteristic. The more offspring that an organism has the better its fitness which is measured by its ability to reproduce itself and survive. Individuals with favorable characteristics, such as having a long neck in the giraffe, or bright white patterns on male peacocks are more likely to others to live and reproduce, which will eventually lead 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 claims that animals acquire traits by use or inactivity. For instance, if the Giraffe's neck grows longer due to stretching to reach for prey, its offspring will inherit a longer neck. The differences in neck length between generations will persist until the giraffe's neck becomes too long to not breed with other giraffes.
Evolution by Genetic Drift
In the process of genetic drift, alleles at a gene may attain different frequencies in a population by chance events. In the end, one will reach fixation (become so common that it can no longer be eliminated through natural selection), while other alleles will fall to lower frequency. In the extreme it can lead to dominance of a single allele. The other alleles are eliminated, and heterozygosity decreases to zero. In a small number of people, this could lead to the complete elimination of the recessive allele. This is known as a bottleneck effect and it is typical of evolutionary process that takes place when a lot of individuals migrate to form a new population.
A phenotypic bottleneck could occur when survivors of a disaster like an epidemic or a massive hunting event, are condensed within a narrow area. The survivors will be largely homozygous for the dominant allele meaning that they all share the same phenotype and consequently have the same fitness traits. This may be caused by war, an earthquake or even a disease. Whatever the reason the genetically distinct population that remains is susceptible to genetic drift.
Walsh, Lewens and Ariew define drift as a deviation from expected values due to differences in fitness. They provide a well-known instance of twins who are genetically identical, have the exact same phenotype but one is struck by lightning and dies, while the other lives and reproduces.
This kind of drift could play a very important role in the evolution of an organism. However, it is not the only method to evolve. The most common alternative is a process known as natural selection, in which the phenotypic diversity of an individual is maintained through mutation and migration.
Stephens argues that there is a significant 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. He argues that a causal mechanism account of drift allows us to distinguish it from these other forces, and this distinction is crucial. He also claims that drift has a direction, that is, it tends to eliminate heterozygosity. It also has a magnitude, which is determined by the size of the population.
Evolution through Lamarckism
When high school students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, often referred to as “Lamarckism”, states that simple organisms develop into more complex organisms by adopting traits that are a product of the use and abuse of an organism. Lamarckism can be demonstrated by the giraffe's neck being extended to reach higher levels of leaves in the trees. This causes the necks of giraffes that are longer to be passed on to their offspring who would grow taller.
Lamarck was a French zoologist and, in his lecture to begin his course on invertebrate Zoology at the Museum of Natural History in Paris on the 17th May 1802, he presented an original idea that fundamentally challenged the conventional wisdom about organic transformation. According to him living things had evolved from inanimate matter via a series of gradual steps. Lamarck was not the first to suggest this but he was considered to be the first to give the subject a comprehensive and general explanation.
The most popular story is that Lamarckism became a rival to Charles Darwin's theory of evolution by natural selection, and that the two theories battled out in the 19th century. Darwinism eventually prevailed which led to what biologists refer to as the Modern Synthesis. The theory denies that acquired characteristics can be passed down and instead, it claims that organisms evolve through the selective action of environment elements, like Natural Selection.
Although Lamarck supported the notion of inheritance through acquired characters and his contemporaries also offered a few words about this idea, it was never a central element in any of their evolutionary theories. simply click the following website page is partly because it was never scientifically tested.
It's been more than 200 year since Lamarck's birth and in the field of age genomics, there is a growing evidence-based body of evidence to support the heritability-acquired characteristics. It is sometimes referred to as "neo-Lamarckism" or, more commonly epigenetic inheritance. This is a variant that is as reliable as the popular Neodarwinian model.
Evolution by the process of adaptation
One of the most popular misconceptions about evolution is that it is driven by a sort of struggle to survive. This is a false assumption and ignores other forces driving evolution. The struggle for survival is more precisely described as a fight to survive within a specific environment, which may be a struggle that involves not only other organisms but also the physical environment itself.
To understand how evolution works, it is helpful to consider what adaptation is. Adaptation refers to any particular characteristic that allows an organism to survive and reproduce in its environment. It could be a physical structure such as feathers or fur. Or it can be a behavior trait that allows you to move towards shade during hot weather, or escaping the cold at night.
The capacity of an organism to extract energy from its environment and interact with other organisms, as well as their physical environment, is crucial to its survival. The organism needs to have the right genes to generate offspring, and it should be able to access enough food and other resources. In addition, the organism should be able to reproduce itself in a way that is optimally within its niche.
These factors, together with mutation and gene flow result in an alteration in the percentage of alleles (different varieties of a particular gene) in the population's gene pool. This change in allele frequency can lead to the emergence of new traits and eventually, new species over time.
Many of the features we appreciate in plants and animals are adaptations. For instance, lungs or gills that extract oxygen from the air feathers and fur for insulation and long legs to get away from predators, and camouflage to hide. However, a complete 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. Behavioral adaptations are not like the tendency of animals to seek out companionship or retreat into shade during hot temperatures. In addition it is important to note that a lack of thought does not mean that something is an adaptation. Failure to consider the consequences of a decision even if it seems to be rational, could make it unadaptive.