What is 에볼루션 바카라 무료체험 ?
Free evolution is the idea that the natural processes of living organisms can cause them to develop over time. This includes the emergence and development of new species.
A variety of examples have been provided of this, including various varieties of fish called sticklebacks that can be found in salt or fresh water, and walking stick insect varieties that prefer particular host plants. These typically reversible traits are not able to explain fundamental changes to basic body plans.
Evolution through Natural Selection
The development of the myriad living creatures on Earth is an enigma that has intrigued scientists for decades. Charles Darwin's natural selection theory is the best-established explanation. This happens when individuals who are better-adapted are able to reproduce faster and longer than those who are less well-adapted. Over time, a population of well-adapted individuals expands and eventually creates a 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 genetic diversity in the species. Inheritance is the passing of a person's genetic characteristics to the offspring of that person which includes both recessive and dominant alleles. Reproduction is the generation of fertile, viable offspring, which includes both sexual and asexual methods.
Natural selection only occurs when all the factors are in equilibrium. For example the case where a dominant allele at the gene allows an organism to live and reproduce more often than the recessive one, the dominant allele will be more prevalent in the population. However, if the gene confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. The process is self-reinforced, meaning that a species with a beneficial trait is more likely to survive and reproduce than an individual with an unadaptive characteristic. The greater an organism's fitness which is measured by its ability to reproduce and survive, is the more offspring it produces. weblink with desirable traits, like having a longer neck in giraffes and bright white patterns of color in male peacocks, are more likely to be able to survive and create offspring, and thus will eventually make up the majority of the population over time.
Natural selection is a factor in populations and not on individuals. This is a major distinction from the Lamarckian theory of evolution which claims that animals acquire characteristics by use or inactivity. If a giraffe expands its neck to catch prey and its neck gets larger, then its offspring will inherit this trait. The differences in neck size between generations will increase until the giraffe becomes unable to reproduce with other giraffes.
Evolution through Genetic Drift
In genetic drift, alleles within a gene can attain different frequencies within a population due to random events. Eventually, only one will be fixed (become widespread enough to not longer be eliminated by natural selection) and the other alleles will diminish in frequency. In the extreme, this leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small number of people it could result in the complete elimination of recessive gene. This is called a bottleneck effect, and it is typical of the kind of evolutionary process that occurs when a large amount of individuals migrate to form a new population.
A phenotypic 'bottleneck' can also occur when the survivors of a disaster like an outbreak or a mass hunting event are concentrated in a small area. The survivors will have an dominant allele, and will have the same phenotype. This can be caused by war, earthquakes or even a plague. Regardless of the cause the genetically distinct population that remains is susceptible to genetic drift.
Walsh Lewens and Ariew employ Lewens, Walsh and Ariew employ a "purely outcome-oriented" definition of drift as any deviation from the expected values for differences in fitness. They cite a famous example of twins that are genetically identical, share the exact same phenotype and yet one is struck by lightning and dies, whereas the other lives and reproduces.
This type of drift is very important in the evolution of an entire species. It is not the only method for evolution. Natural selection is the main alternative, in which mutations and migrations maintain the phenotypic diversity of the population.
Stephens asserts that there is a big distinction between treating drift as a force, or an underlying cause, and treating other causes of evolution, such as mutation, selection and migration as causes or causes. He claims that a causal-process model of drift allows us to differentiate it from other forces, and this differentiation is crucial. He also argues that drift has both an orientation, i.e., it tends to eliminate heterozygosity. It also has a size, that is determined by the size of the population.
Evolution through Lamarckism
In high school, students take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is often known as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inherited characteristics that result from the organism's natural actions use and misuse. Lamarckism can be demonstrated by a giraffe extending its neck to reach higher levels of leaves in the trees. This would cause the necks of giraffes that are longer to be passed to their offspring, who would then become taller.
Lamarck Lamarck, a French Zoologist, introduced an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged conventional wisdom on organic transformation. According to him living things had evolved from inanimate matter via an escalating series of steps. Lamarck was not the first to propose this but he was considered to be the first to give the subject a comprehensive and general treatment.
The prevailing story is that Lamarckism was an opponent to Charles Darwin's theory of evolution through natural selection and both theories battled it out in the 19th century. Darwinism ultimately won, leading to what biologists call the Modern Synthesis. This theory denies the possibility that acquired traits can be inherited, and instead, it argues that organisms develop through the selective action of environmental factors, including natural selection.
Lamarck and his contemporaries supported the idea that acquired characters could be passed on to the next generation. However, this idea was never a central part of any of their theories about evolution. This is partly because it was never scientifically tested.
But it is now more than 200 years since Lamarck was born and in the age genomics there is a vast body of evidence supporting the possibility of inheritance of acquired traits. This is also referred to as "neo Lamarckism", or more commonly epigenetic inheritance. It is a version of evolution that is as valid as the more popular neo-Darwinian model.
Evolution by adaptation
One of the most common misconceptions about evolution is its being driven by a fight for survival. In reality, this notion misrepresents natural selection and ignores the other forces that are driving evolution. The struggle for survival is more accurately described as a struggle to survive within a specific environment, which can be a struggle that involves not only other organisms, but as well the physical environment.
Understanding how adaptation works is essential to comprehend evolution. The term "adaptation" refers to any specific feature that allows an organism to live and reproduce in its environment. It could be a physical structure, like fur or feathers. Or it can be a characteristic of behavior such as moving towards shade during the heat, or coming out to avoid the cold at night.
The capacity of an organism to draw energy from its surroundings and interact with other organisms and their physical environments, is crucial to its survival. The organism must have the right genes for producing offspring, and be able to find sufficient food and resources. The organism must be able to reproduce itself at the rate that is suitable for its specific niche.
These elements, along with mutations and gene flow can result in an alteration in the ratio of different alleles in the population's gene pool. This change in allele frequency could lead to the development of new traits and eventually new species over time.
Many of the characteristics we admire about animals and plants are adaptations, like lungs or gills to extract oxygen from the air, feathers or fur to protect themselves and long legs for running away from predators and camouflage to hide. To understand adaptation, it is important to differentiate between physiological and behavioral traits.
Physiological adaptations like thick fur or gills are physical traits, while behavioral adaptations, such as the desire to find friends or to move to shade in hot weather, are not. It is also important to note that insufficient planning does not make an adaptation. In fact, a failure to consider the consequences of a behavior can make it unadaptable, despite the fact that it may appear to be reasonable or even essential.
