What is Free Evolution?
Free evolution is the idea that natural processes can cause organisms to develop over time. This includes the evolution of new species and alteration of the appearance of existing species.
Numerous examples have been offered of this, including different varieties of stickleback fish that can live in fresh or salt water and walking stick insect varieties that are attracted to particular host plants. These 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 living creatures that live on our planet for many centuries. The most well-known explanation is Charles Darwin's natural selection process, a process that occurs when individuals that are better adapted survive and reproduce more effectively than those that are less well-adapted. As 에볼루션코리아 , the number of individuals who are well-adapted grows and eventually creates a new species.
Natural selection is a process that is cyclical and involves the interaction of 3 factors including reproduction, variation and inheritance. Sexual reproduction and mutation increase genetic diversity in an animal species. Inheritance is the term used to describe the transmission of genetic traits, which include recessive and dominant genes, to their offspring. Reproduction is the process of creating fertile, viable offspring. This can be accomplished by both asexual or sexual methods.
All of these variables must be in balance for natural selection to occur. For instance the case where a dominant allele at one gene causes an organism to survive and reproduce more frequently than the recessive one, the dominant allele will be more common in the population. If the allele confers a negative survival advantage or reduces the fertility of the population, it will go away. This process is self-reinforcing meaning that an organism with a beneficial characteristic will survive and reproduce more than one with an inadaptive characteristic. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the greater number of offspring it produces. People with good traits, like a longer neck in giraffes, or bright white color patterns in male peacocks, are more likely to survive and produce offspring, which means they will make up the majority of the population over time.
Natural selection is only a force for populations, not on individuals. This is a significant distinction from the Lamarckian theory of evolution, which claims that animals acquire characteristics through use or neglect. For example, if a animal's neck is lengthened by reaching out to catch prey, its offspring will inherit a longer neck. The differences in neck size between generations will continue to increase until the giraffe is unable to breed with other giraffes.
Evolution by Genetic Drift
Genetic drift occurs when the alleles of one gene are distributed randomly 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 diminish in frequency. In the extreme it can lead to dominance of a single allele. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small population it could result in the complete elimination of recessive gene. This is known as a bottleneck effect and it is typical of evolutionary process that takes place when a large number of individuals move to form a new population.
A phenotypic bottleneck can also occur when the survivors of a disaster such as an outbreak or a mass hunting event are confined to an area of a limited size. The survivors will share a dominant allele and thus will share the same phenotype. This situation could be caused by earthquakes, war, or even plagues. Whatever the reason the genetically distinct population that remains could be susceptible to genetic drift.
Walsh Lewens, Lewens, and Ariew use Lewens, Walsh and Ariew employ a "purely outcome-oriented" definition of drift as any deviation from the expected values of different fitness levels. They give a famous example of twins that are genetically identical, share the exact same phenotype and yet one is struck by lightning and dies, while the other lives and reproduces.
This type of drift is crucial in the evolution of an entire species. It is not the only method for evolution. 에볼루션 바카라사이트 is to use a process known as natural selection, where the phenotypic diversity of an individual is maintained through mutation and migration.
Stephens asserts that there is a major distinction between treating drift as a force or a cause and treating other causes of evolution like selection, mutation and migration as causes or causes. He claims that a causal mechanism account of drift permits us to differentiate it from the other forces, and this distinction is vital. He also argues that drift has direction, i.e., it tends to reduce heterozygosity. It also has a size which is determined by population size.
Evolution through Lamarckism
When students in high school take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, commonly called "Lamarckism which means that simple organisms evolve into more complex organisms through taking on traits that result from the organism's use and misuse. Lamarckism is illustrated through an giraffe's neck stretching to reach higher levels of leaves in the trees. This could cause the longer necks of giraffes to be passed to their offspring, who would grow taller.
Lamarck, a French Zoologist, introduced an innovative idea in his opening lecture at the Museum of Natural History of Paris. He challenged conventional wisdom on organic transformation. According Lamarck, living organisms evolved from inanimate material through a series of gradual steps. Lamarck was not the first to suggest that this might be the case but his reputation is widely regarded as having given the subject its first broad and comprehensive treatment.
The most popular story is that Lamarckism grew into an opponent to Charles Darwin's theory of evolution through natural selection and that the two theories fought each other in the 19th century. Darwinism eventually won and led to the development of what biologists today refer to as the Modern Synthesis. The Modern Synthesis theory denies that acquired characteristics can be inherited and instead, it argues that organisms develop through the selective action of environmental factors, such as natural selection.
While Lamarck supported the notion of inheritance by acquired characters and his contemporaries spoke of this idea, it was never a central element in any of their evolutionary theories. This is largely due to the fact that it was never validated scientifically.
It's been over 200 years since the birth of Lamarck and in the field of age genomics there is a growing body of evidence that supports the heritability of acquired traits. This is also referred to as "neo Lamarckism", or more generally epigenetic inheritance. It is a version of evolution that is just as valid as the more well-known neo-Darwinian model.
Evolution through Adaptation
One of the most common misconceptions about evolution is that it is a result of a kind of struggle for survival. In fact, this view is a misrepresentation of natural selection and ignores the other forces that are driving evolution. The fight for survival can be more accurately described as a struggle to survive in a specific environment, which may be a struggle that involves not only other organisms, but also the physical environment itself.
Understanding how adaptation works is essential to understand evolution. Adaptation refers to any particular characteristic that allows an organism to survive and reproduce in its environment. It can be a physiological structure such as fur or feathers or a behavioral characteristic such as a tendency to move into the shade in hot weather or coming out at night to avoid the cold.
The ability of an organism to extract energy from its environment and interact with other organisms, as well as their physical environments, is crucial to its survival. The organism needs to have the right genes to produce offspring, and must be able to access enough food and other resources. The organism must be able to reproduce itself at the rate that is suitable for its particular niche.
These factors, together with gene flow and mutation result in changes in the ratio of alleles (different forms of a gene) in the gene pool of a population. This change in allele frequency can lead to the emergence of new traits, and eventually new species over time.
Many of the features we admire in animals and plants are adaptations. For example, lungs or gills that draw oxygen from air feathers and fur for insulation, long legs to run away from predators and camouflage to conceal. However, a proper understanding of adaptation requires a keen eye to the distinction between physiological and behavioral traits.
Physiological traits like thick fur and gills are physical traits. The behavioral adaptations aren't, such as the tendency of animals to seek companionship or to retreat into the shade in hot temperatures. It is important to note that insufficient planning does not result in an adaptation. Failure to consider the effects of a behavior even if it appears to be rational, may make it inflexible.