What is Free Evolution?
Free evolution is the concept that the natural processes of organisms can lead them to evolve over time. This includes the development of new species and change in appearance of existing species.
Many examples have been given of this, including different kinds of stickleback fish that can live in either fresh or salt water and walking stick insect varieties that prefer specific host plants. These are mostly reversible traits however, are not able to explain fundamental changes in basic body plans.
Evolution through Natural Selection
Scientists have been fascinated by the evolution of all the living organisms that inhabit our planet for many centuries. The best-established explanation is Darwin's natural selection, an evolutionary process that occurs when individuals that are better adapted survive and reproduce more effectively than those less well adapted. Over time, a population of well-adapted individuals increases and eventually creates a new species.
Natural selection is a process that is cyclical and involves the interaction of three factors including reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which increase the genetic diversity within the species. Inheritance refers to the passing of a person's genetic characteristics to his or her offspring, which includes both dominant and recessive alleles. Reproduction is the generation of fertile, viable offspring, which includes both asexual and sexual methods.
All of these factors have to be in equilibrium for natural selection to occur. If, for instance an allele of a dominant gene makes an organism reproduce and last longer than the recessive allele The dominant allele becomes more prevalent in a population. However, if the allele confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. This process is self-reinforcing meaning that an organism that has an adaptive trait will live and reproduce far more effectively than one with a maladaptive characteristic. The more offspring an organism can produce, the greater its fitness which is measured by its ability to reproduce and survive. 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, so they will eventually make up the majority of the population over time.
Natural selection is only an aspect of populations and not on individuals. This is a significant distinction from the Lamarckian theory of evolution, which argues that animals acquire characteristics through use or disuse. If 에볼루션 카지노 사이트 extends its neck in order to catch prey, and the neck becomes longer, then the offspring will inherit this trait. The length difference between generations will persist until the giraffe's neck gets too long to no longer breed with other giraffes.
Evolution through Genetic Drift
In the process of genetic drift, alleles of a gene could reach different frequencies in a population through random events. At some point, one will attain fixation (become so widespread that it is unable to be removed by natural selection), while other alleles fall to lower frequencies. In the extreme this, it leads to dominance of a single allele. The other alleles are essentially eliminated, and heterozygosity decreases to zero. In a small group this could result in the complete elimination of recessive allele. This is known as the bottleneck effect. It is typical of the evolutionary process that occurs when the number of individuals migrate to form a population.
A phenotypic bottleneck can also occur when survivors of a disaster such as an outbreak or mass hunting event are concentrated in an area of a limited size. The remaining individuals are likely to be homozygous for the dominant allele meaning that they all have the same phenotype, and therefore have the same fitness characteristics. This situation could be caused by earthquakes, war or even a plague. The genetically distinct population, if it remains vulnerable to genetic drift.
Walsh Lewens and Ariew employ Lewens, Walsh, and Ariew use a "purely outcome-oriented" definition of drift as any deviation from expected values for variations in fitness. They give the famous example of twins that are genetically identical and have exactly the same phenotype. However one is struck by lightning and dies, but the other lives to reproduce.
This type of drift is crucial in the evolution of an entire species. However, it's not the only way to evolve. The primary alternative is to use a process known as natural selection, in which the phenotypic variation of an individual is maintained through mutation and migration.
Stephens claims that there is a significant difference between treating drift as a force, or an underlying cause, and treating other causes of evolution such as selection, mutation and migration as forces or causes. He argues that a causal-process account of drift allows us separate it from other forces, and this distinction is essential. He further argues that drift has both an orientation, i.e., it tends to reduce heterozygosity. It also has a size, which is determined by the size of the population.
Evolution through Lamarckism
In high school, students study biology they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is generally known as "Lamarckism" and it asserts that simple organisms evolve into more complex organisms via the inherited characteristics that are a result of the natural activities of an organism, use and disuse. Lamarckism is illustrated through the giraffe's neck being extended to reach higher branches in the trees. This would cause the longer necks of giraffes to be passed to their offspring, who would then become 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 of May in 1802, he introduced an innovative concept that completely challenged previous thinking about organic transformation. In his opinion living things had evolved from inanimate matter through the gradual progression of events. Lamarck wasn't the first to make this claim but he was regarded as the first to give the subject a comprehensive and general explanation.
The popular narrative is that Lamarckism grew into a rival to Charles Darwin's theory of evolution through natural selection, and that the two theories battled out in the 19th century. Darwinism ultimately prevailed which led to what biologists refer to as the Modern Synthesis. The Modern Synthesis theory denies the possibility that acquired traits can be inherited, and instead suggests that organisms evolve through the selective action of environmental factors, such as natural selection.
Although Lamarck believed in the concept of inheritance by acquired characters and his contemporaries also offered a few words about this idea however, it was not a major feature in any of their evolutionary theories. This is due in part 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 vast body of evidence supporting the heritability of acquired characteristics. This is also referred to as "neo Lamarckism", or more commonly epigenetic inheritance. This is a variant that is as valid as the popular Neodarwinian model.
Evolution through Adaptation
One of the most popular misconceptions about evolution is that it is driven by a type of struggle to survive. This view is inaccurate and ignores other forces driving evolution. The fight for survival can be more precisely described as a fight to survive within a particular environment, which could be a struggle that involves not only other organisms, but as well the physical environment.
Understanding the concept of adaptation is crucial to comprehend evolution. It is a feature that allows living organisms to live in its environment and reproduce. It could be a physiological structure such as fur or feathers or a behavior such as a tendency to move to the shade during the heat or leaving at night to avoid the cold.
The survival of an organism depends on its ability to obtain energy from the environment and to interact with other living organisms and their physical surroundings. The organism needs to have the right genes to generate offspring, and it must be able to access sufficient food and other resources. The organism should also be able reproduce itself at the rate that is suitable for its particular niche.
These elements, along with mutations and gene flow can result in a shift in the proportion of different alleles in the population's gene pool. Over time, this change in allele frequencies can lead to the emergence of new traits and ultimately new species.
A lot of the traits we admire in animals and plants are adaptations. For example lung or gills that extract oxygen from air, fur and feathers as insulation long legs to run away from predators and camouflage to conceal. However, a proper understanding of adaptation requires paying attention to the distinction between physiological and behavioral characteristics.
Physical traits such as large gills and thick fur are physical traits. Behavior adaptations aren't like the tendency of animals to seek out companionship or move into the shade in hot weather. It is important to remember that a lack of planning does not make an adaptation. In fact, a failure to think about the implications of a behavior can make it unadaptive even though it may appear to be logical or even necessary.