What Free Evolution Experts Would Like You To Learn
What is Free Evolution?
Free evolution is the concept that the natural processes of living organisms can lead to their development over time. This includes the appearance and growth of new species.
Numerous examples have been offered of this, including various varieties of stickleback fish that can live in either fresh or salt water and walking stick insect varieties that are attracted to specific host plants. These mostly reversible trait permutations can't, however, be the reason for fundamental changes in body plans.
Evolution by Natural Selection
The evolution of the myriad living creatures on Earth is an enigma that has fascinated scientists for centuries. The most widely accepted explanation is Darwin's natural selection process, which occurs when individuals that are better adapted survive and reproduce more successfully than those that are less well adapted. As time passes, the number of well-adapted individuals becomes larger and eventually creates an entirely new species.
Natural selection is a process that is cyclical and involves the interaction of three factors that are: reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within an animal species. Inheritance is the term used to describe the transmission of a person's genetic traits, including both dominant and recessive genes to their offspring. Reproduction is the process of creating fertile, viable offspring. This can be done through sexual or asexual methods.
Natural selection only occurs when all these elements are in harmony. For instance, if a dominant allele at the gene allows an organism to live and reproduce more frequently than the recessive allele the dominant allele will become more prevalent within the population. However, if the gene confers an unfavorable survival advantage or reduces fertility, it will be eliminated from the population. The process is self-reinforcing, which means that an organism with a beneficial trait can reproduce and survive longer than an individual with an unadaptive trait. The more offspring an organism can produce the more fit it is, 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 and eventually lead to them becoming the majority.
Natural selection is an element in the population and not on individuals. This is a significant distinction from the Lamarckian theory of evolution, which states that animals acquire traits through use or disuse. For example, if a Giraffe's neck grows longer due to reaching out to catch prey its offspring will inherit a larger neck. The differences in neck size between generations will continue to increase until the giraffe becomes unable to reproduce with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when alleles from the same gene are randomly distributed within a population. Eventually, one of them will reach fixation (become so common that it cannot be eliminated by natural selection), while other alleles fall to lower frequency. In extreme cases this, it leads to dominance of a single allele. The other alleles have been essentially eliminated and heterozygosity has diminished to a minimum. In a small group this could result in the total elimination of the recessive allele. This is known as the bottleneck effect. It is typical of an evolutionary process that occurs when the number of individuals migrate to form a population.
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 be largely homozygous for the dominant allele, which means they will all share the same phenotype and consequently have the same fitness characteristics. This could be caused by war, an earthquake or even a cholera outbreak. Regardless of the cause the genetically distinct group that remains could be prone to genetic drift.
Walsh Lewens, Lewens, and Ariew utilize Lewens, Walsh, and Ariew use a "purely outcome-oriented" definition of drift as any deviation from expected values for different fitness levels. They give the famous example of twins who are both genetically identical and have exactly the same phenotype. However one is struck by lightning and dies, but the other continues to reproduce.
This kind of drift can be very important in the evolution of an entire species. However, it is not the only method to evolve. The most common alternative is a process called natural selection, in which the phenotypic diversity of the population is maintained through mutation and migration.
Stephens argues there is a significant difference between treating drift like an agent or cause and treating other causes like migration and selection as forces and causes. He argues that a causal-process explanation of drift lets us separate it from other forces, and this distinction is essential. He also argues that drift is both a direction, i.e., it tends to eliminate heterozygosity. It also has a size which is determined based on population size.
Evolution by Lamarckism
Students of biology in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution, often referred to as "Lamarckism, states that simple organisms develop into more complex organisms 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 branches in the trees. This could cause giraffes to pass on their longer necks to their offspring, which then get taller.
Lamarck was a French zoologist and, in his inaugural lecture for 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 previous understanding of organic transformation. According to him living things evolved from inanimate matter via an escalating series of steps. Lamarck wasn't the first to propose this but he was regarded as the first to offer the subject a comprehensive and general overview.
The popular narrative is that Lamarckism was a rival to Charles Darwin's theory of evolutionary natural selection, and that the two theories fought each other in the 19th century. Darwinism eventually triumphed and led to the development of what biologists now call the Modern Synthesis. The Modern Synthesis theory denies that traits acquired through evolution can be inherited, and instead suggests that organisms evolve by the symbiosis of environmental factors, such as natural selection.
While Lamarck believed in the concept of inheritance by acquired characters and his contemporaries also offered a few words about this idea, it was never a major feature in any of their evolutionary theorizing. This is partly due to the fact that it was never tested scientifically.
It's been more than 200 years since Lamarck was born and in the age of genomics, there is a large amount of evidence that supports the heritability of acquired characteristics. It is sometimes referred to as "neo-Lamarckism" or, more commonly, epigenetic inheritance. It is a form of evolution that is just as relevant as the more popular Neo-Darwinian model.
Evolution through adaptation
One of the most common misconceptions about evolution is that it is being driven by a struggle for survival. In fact, this view is inaccurate and overlooks the other forces that drive evolution. The struggle for survival is more accurately described as a struggle to survive within a specific environment, which may involve not only other organisms, but also the physical environment itself.
Understanding adaptation is important to comprehend evolution. The term "adaptation" refers to any specific feature that allows an organism to live and reproduce within its environment. It could be a physiological feature, like feathers or fur or a behavioral characteristic 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 extract energy from the environment and interact with other living organisms and their physical surroundings. The organism should possess the right genes for producing offspring, and be able to find sufficient food and resources. The organism should also be able reproduce at a rate that is optimal for its particular niche.
These elements, in conjunction with mutation and gene flow can result in changes in the ratio of alleles (different forms of a gene) in a population's gene pool. This change in allele frequency can result in the emergence of new traits and eventually, new species in the course of time.
Many of the characteristics we admire in animals and plants are adaptations. For instance, lungs or gills that draw oxygen from air, fur and feathers as insulation long legs to run away from predators and camouflage to conceal. However, Suggested Resource site of adaptation requires attention to the distinction between physiological and behavioral characteristics.
Physiological adaptations, like thick fur or gills are physical traits, whereas behavioral adaptations, such as the tendency to search for companions or to retreat to the shade during hot weather, are not. It is also important to remember that a the absence of planning doesn't make an adaptation. A failure to consider the implications of a choice even if it seems to be rational, could make it inflexible.