What is Free Evolution?
Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the creation of new species and change in appearance of existing ones.
This is evident in many examples, including stickleback fish varieties that can thrive in salt or fresh water, and walking stick insect types that prefer specific host plants. These are mostly reversible traits, however, cannot explain fundamental changes in body plans.
Evolution by Natural Selection
The evolution of the myriad living organisms on Earth is an enigma that has intrigued scientists for many centuries. The most widely accepted explanation is Charles Darwin's natural selection, an evolutionary process that 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 well-adapted individuals grows and eventually develops into an entirely new species.
Natural selection is an ongoing process and involves the interaction of 3 factors that are: reproduction, variation and inheritance. Sexual reproduction and mutation increase the genetic diversity of the species. Inheritance refers the transmission of a person’s genetic characteristics, which includes both dominant and recessive genes and their offspring. Reproduction is the process of producing viable, fertile offspring. This can be accomplished via sexual or asexual methods.
All of these factors must be in harmony for natural selection to occur. For instance, if a dominant allele at a gene causes an organism to survive and reproduce more frequently than the recessive one, the dominant allele will become more prominent in the population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will be eliminated. This process is self-reinforcing which means that the organism with an adaptive trait will survive and reproduce far more effectively than one 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 live. Individuals with favorable traits, like longer necks in giraffes, or bright white color patterns in male peacocks, are more likely to survive and have offspring, so they will make up the majority of the population over time.
Natural selection is only 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 through use or neglect. For instance, if a animal's neck is lengthened by reaching out to catch prey and its offspring will inherit a more long neck. The differences in neck length between generations will continue until the giraffe's neck becomes so long that it can not breed with other giraffes.
Evolution by Genetic Drift
Genetic drift occurs when the alleles of the same gene are randomly distributed in a group. In the end, only one will be fixed (become common enough that it can no longer be eliminated by natural selection) and the other alleles diminish in frequency. In extreme cases this, it leads to a single allele dominance. The other alleles are essentially eliminated, and heterozygosity is reduced to zero. In a small population, this could lead to the complete elimination of recessive allele. This scenario is called the bottleneck effect. It is typical of an evolutionary process that occurs whenever a large number individuals migrate to form a group.
A phenotypic bottleneck may also occur when the survivors of a catastrophe such as an outbreak or mass hunt incident are concentrated in a small area. The survivors will carry an dominant allele, and will have the same phenotype. This can be caused by war, earthquakes or even a plague. Whatever the reason, the genetically distinct population that remains is prone to genetic drift.
Walsh Lewens, Walsh and Ariew define drift as a deviation from expected values due to differences in fitness. They give the famous example of twins who are both genetically identical and share the same phenotype. However one is struck by lightning and dies, while the other is able to reproduce.
This kind of drift could play a very important role in the evolution of an organism. This isn't the only method for evolution. Natural selection is the primary alternative, in which mutations and migration maintain the phenotypic diversity of a population.
Stephens asserts that there is a vast distinction between treating drift as an agent or cause and considering other causes, such as migration and selection mutation as causes and forces. Stephens claims that a causal process account of drift allows us distinguish it from other forces, and this differentiation is crucial. He argues further that drift has an orientation, i.e., it tends to eliminate heterozygosity. It also has a size, that is determined by population size.
에볼루션바카라 by Lamarckism
Biology students in high school are often exposed to Jean-Baptiste lamarck's (1744-1829) work. His theory of evolution, often called "Lamarckism which means that simple organisms evolve into more complex organisms adopting traits that result from the use and abuse of an organism. Lamarckism is typically illustrated by a picture of a giraffe extending its neck to reach higher up in the trees. This would cause the necks of giraffes that are longer to be passed on to their offspring who would then grow even taller.
Lamarck the French Zoologist, introduced an innovative idea in his opening lecture at the Museum of Natural History of Paris. He challenged the traditional thinking about organic transformation. According to him living things evolved from inanimate matter through an escalating series of steps. Lamarck was not the first to suggest that this could be the case but he is widely seen as giving the subject its first broad and thorough treatment.
The prevailing story is that Lamarckism became a rival to Charles Darwin's theory of evolution through natural selection and that the two theories battled each other in the 19th century. Darwinism eventually prevailed, leading to the development of what biologists today refer to as the Modern Synthesis. 에볼루션 무료 바카라 argues that acquired traits can be passed down through generations and instead argues that organisms evolve through the selective influence of environmental elements, like Natural Selection.
Although Lamarck endorsed the idea of inheritance by acquired characters, and his contemporaries also spoke of this idea but it was not an integral part of any of their evolutionary theorizing. This is largely due to the fact that it was never tested scientifically.
However, it has been more than 200 years since Lamarck was born and in the age of genomics, there is a large amount of evidence to support the possibility of inheritance of acquired traits. This is also known as "neo Lamarckism", or more often epigenetic inheritance. This is a model that is as reliable as the popular neodarwinian model.
Evolution by adaptation
One of the most common misconceptions about evolution is that it is a result of a kind of struggle to survive. In reality, this notion misrepresents natural selection and ignores the other forces that are driving evolution. The struggle for existence is better described as a struggle to survive in a particular environment. This can include not just other organisms as well as the physical surroundings themselves.
To understand how evolution works it is beneficial to understand what is adaptation. The term "adaptation" refers to any specific characteristic that allows an organism to live and reproduce in its environment. It can be a physiological feature, such as fur or feathers or a behavior, such as moving into shade in hot weather or coming out at night to avoid cold.
The survival of an organism depends on its ability to extract energy from the environment and to interact with other organisms and their physical environments. The organism needs to have the right genes to produce offspring, and it must be able to find enough food and other resources. The organism should also be able to reproduce itself at an amount that is appropriate for its niche.
에볼루션바카라 , along with gene flow and mutations, can lead to an alteration in the ratio of different alleles within the gene pool of a population. 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 features we find appealing in plants and animals are adaptations. For example the lungs or gills which extract oxygen from air feathers and fur as insulation long legs to run away from predators, and camouflage to hide. However, a thorough understanding of adaptation requires attention to the distinction between the physiological and behavioral characteristics.
Physiological traits like large gills and thick fur are physical characteristics. The behavioral adaptations aren't an exception, for instance, the tendency of animals to seek out companionship or to retreat into the shade in hot temperatures. Furthermore it is important to note that lack of planning does not make something an adaptation. In fact, failing to consider the consequences of a behavior can make it unadaptive even though it appears to be reasonable or even essential.