Free Evolution Strategies That Will Change Your Life
What is Free Evolution?
Free evolution is the notion that natural processes can cause organisms to evolve over time. This includes the development of new species and alteration of the appearance of existing ones.
This has been demonstrated by numerous examples of stickleback fish species that can live in fresh or saltwater and walking stick insect species that are apprehensive about particular host plants. These typically reversible traits cannot explain fundamental changes to the body's basic plans.
Evolution by Natural Selection
Scientists have been fascinated by the evolution of all the living creatures that inhabit our planet for centuries. The most well-known explanation is that of Charles Darwin's natural selection, which is triggered when more well-adapted individuals live longer and reproduce more successfully than those that are less well-adapted. As time passes, the number of individuals who are well-adapted grows and eventually forms a new species.
Natural selection is a process that is cyclical and involves the interaction of three factors including reproduction, variation and inheritance. Mutation and sexual reproduction increase the genetic diversity of the species. Inheritance refers to the transmission of a person’s genetic traits, including recessive and dominant genes to their offspring. Reproduction is the process of creating viable, fertile offspring. This can be achieved through sexual or asexual methods.
All of these factors must be in harmony for natural selection to occur. If, for instance, a dominant gene allele allows an organism to reproduce and last longer than the recessive gene The dominant allele becomes more prevalent in a population. However, if the gene confers a disadvantage in survival or reduces fertility, it will be eliminated from the population. The process is self reinforcing, which means that an organism that has an adaptive characteristic will live and reproduce far more effectively than those with a maladaptive trait. The higher the level of fitness an organism has as measured by its capacity to reproduce and survive, is the greater number of offspring it produces. People with desirable traits, like the long neck of Giraffes, or the bright white patterns on male peacocks are more likely to others to survive and reproduce, which will eventually lead to them becoming the majority.
Natural selection is only an element in the population and not on individuals. This is a significant distinction from the Lamarckian evolution theory which holds that animals acquire traits through use or lack of use. If a giraffe stretches its neck to reach prey, and the neck becomes larger, then its offspring will inherit this characteristic. The difference in neck length between generations will continue until the neck of the giraffe becomes too long that it can not breed with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when alleles from the same gene are randomly distributed in a population. Eventually, only one will be fixed (become widespread enough to not longer be eliminated through natural selection) and the other alleles will decrease in frequency. This can result in dominance in extreme. Other alleles have been essentially eliminated and heterozygosity has been reduced to zero. In a small group it could result in the complete elimination of the recessive gene. Such a scenario would be known as a bottleneck effect and it is typical of the kind of evolutionary process when a lot of individuals move to form a new population.
A phenotypic bottleneck could happen when the survivors of a disaster such as an epidemic or mass hunting event, are concentrated into a small area. The survivors will share a dominant allele and thus will have the same phenotype. This could be caused by a war, earthquake or even a cholera outbreak. The genetically distinct population, if it is left susceptible to genetic drift.
Walsh, Lewens and Ariew define drift as a deviation from expected values due to differences in fitness. They cite a famous instance of twins who are genetically identical, share identical phenotypes but one is struck by lightning and dies, whereas the other lives and reproduces.
This kind of drift can play a very important part in the evolution of an organism. This isn't the only method for evolution. Natural selection is the primary alternative, where mutations and migration keep the phenotypic diversity of a population.
Stephens argues there is a huge difference between treating drift like an actual cause or force, and considering other causes, such as migration and selection mutation as forces and causes. He argues that a causal-process account of drift allows us distinguish it from other forces and that this distinction is crucial. He further argues that drift has direction, i.e., it tends to eliminate heterozygosity. It also has a size that is determined by population size.
Evolution through Lamarckism
Students of biology in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution, also called "Lamarckism which means that simple organisms develop into more complex organisms taking on traits that are a product of the use and abuse of an organism. Lamarckism can be illustrated by a giraffe extending its neck to reach higher leaves in the trees. This could cause giraffes to pass on their longer necks to offspring, who would then become taller.
Lamarck was a French zoologist and, in his inaugural lecture for his course on invertebrate zoology held at the Museum of Natural History in Paris on 17 May 1802, he presented an original idea that fundamentally challenged the conventional wisdom about organic transformation. In his opinion, living things had evolved from inanimate matter via an escalating series of steps. Lamarck was not the only one to suggest that this might be the case but the general consensus is that he was the one giving the subject its first general and comprehensive analysis.
The most popular story is that Charles Darwin's theory on evolution by natural selection and Lamarckism fought in the 19th Century. Darwinism eventually prevailed and led to the creation of what biologists call the Modern Synthesis. This theory denies the possibility that acquired traits can be inherited, and instead argues that organisms evolve through the action of environmental factors, including natural selection.
Although Lamarck endorsed the idea of inheritance by acquired characters and his contemporaries also paid lip-service to this notion but it was not an integral part of any of their evolutionary theories. 에볼루션 is due to the fact that it was never tested scientifically.
But 에볼루션 무료체험 is now 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 sometimes referred to as "neo-Lamarckism" or, more frequently epigenetic inheritance. This is a variant that is just as valid as the popular Neodarwinian model.
Evolution by the process of adaptation
One of the most common misconceptions about evolution is that it is driven by a sort of struggle for survival. This is a false assumption and overlooks other forces that drive evolution. The struggle for survival is more effectively described as a struggle to survive within a specific environment, which may include not just other organisms, but also the physical environment.
To understand how evolution works it is important to understand what is adaptation. The term "adaptation" refers to any specific feature that allows an organism to live and reproduce in its environment. It can be a physiological structure like feathers or fur, or a behavioral trait such as a tendency to move into the shade in hot weather or coming out at night to avoid the cold.
The survival of an organism is dependent on its ability to draw energy from the environment and to interact with other organisms and their physical environments. The organism needs to have the right genes to create offspring, and must be able to locate enough food and other resources. Furthermore, the organism needs to be capable of reproducing in a way that is optimally within its niche.
These factors, together with mutation and gene flow, lead to a change in the proportion of alleles (different forms of a gene) in the gene pool of a population. This change in allele frequency can result in the emergence of new traits, and eventually, new species over time.
Many of the characteristics we admire in animals and plants are adaptations, for example, lung or gills for removing oxygen from the air, fur or feathers to protect themselves and long legs for running away from predators and camouflage for hiding. However, a proper understanding of adaptation requires attention to the distinction between physiological and behavioral traits.
Physiological traits like large gills and thick fur are physical characteristics. The behavioral adaptations aren't, such as the tendency of animals to seek companionship or retreat into shade during hot weather. Furthermore it is important to remember that a lack of forethought is not a reason to make something an adaptation. A failure to consider the implications of a choice even if it appears to be rational, could cause it to be unadaptive.