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Evolution Explained The most fundamental concept is that living things change over time. These changes help the organism to survive or reproduce better, or to adapt to its environment. Scientists have utilized the new science of genetics to describe how evolution functions. They have also used the physical science to determine how much energy is required for these changes. Natural Selection For evolution to take place, organisms need to be able to reproduce and pass their genetic traits on to future generations. This is known as natural selection, sometimes called “survival of the fittest.” However, the phrase “fittest” could be misleading since it implies that only the most powerful or fastest organisms will survive and reproduce. The most well-adapted organisms are ones that can adapt to the environment they reside in. Moreover, environmental conditions can change quickly and if a population isn't well-adapted it will be unable to survive, causing them to shrink, or even extinct. The most fundamental element of evolution is natural selection. This occurs when advantageous traits are more common as time passes which leads to the development of new species. This process is primarily driven by heritable genetic variations of organisms, which are a result of mutations and sexual reproduction. Any force in the world that favors or disfavors certain characteristics can be an agent that is selective. These forces can be biological, like predators, or physical, like temperature. Over time, populations exposed to different agents of selection may evolve so differently that they no longer breed together and are considered to be separate species. Natural selection is a straightforward concept however, it isn't always easy to grasp. Even among scientists and educators there are a myriad of misconceptions about the process. 에볼루션 사이트 have revealed that students' levels of understanding of evolution are only associated with their level of acceptance of the theory (see the references). For example, Brandon's focused definition of selection relates only to differential reproduction and does not include replication or inheritance. Havstad (2011) is one of many authors who have advocated for a more broad concept of selection that encompasses Darwin's entire process. This would explain the evolution of species and adaptation. In addition, there are a number of cases in which a trait increases its proportion in a population, but does not increase the rate at which individuals who have the trait reproduce. These situations are not classified as natural selection in the strict sense but could still be in line with Lewontin's requirements for a mechanism like this to work, such as when parents with a particular trait produce more offspring than parents with it. Genetic Variation Genetic variation is the difference in the sequences of the genes of the members of a particular species. Natural selection is one of the major forces driving evolution. Mutations or the normal process of DNA changing its structure during cell division could cause variations. Different genetic variants can cause distinct traits, like the color of your eyes, fur type or ability to adapt to unfavourable environmental conditions. If a trait is beneficial it is more likely to be passed down to the next generation. This is referred to as an advantage that is selective. Phenotypic plasticity is a special kind of heritable variation that allows individuals to modify their appearance and behavior as a response to stress or the environment. These modifications can help them thrive in a different environment or take advantage of an opportunity. For example they might grow longer fur to shield themselves from the cold or change color to blend into a particular surface. These phenotypic changes, however, are not necessarily affecting the genotype, and therefore cannot be thought to have contributed to evolutionary change. Heritable variation enables adapting to changing environments. It also enables natural selection to function by making it more likely that individuals will be replaced in a population by individuals with characteristics that are suitable for the particular environment. However, in some instances, the rate at which a genetic variant is passed on to the next generation isn't fast enough for natural selection to keep up. Many harmful traits like genetic diseases persist in populations despite their negative consequences. This is due to a phenomenon referred to as diminished penetrance. It means that some people with the disease-associated variant of the gene do not exhibit symptoms or signs of the condition. Other causes include gene by environmental interactions as well as non-genetic factors like lifestyle or diet as well as exposure to chemicals. In order to understand the reason why some undesirable traits are not eliminated through natural selection, it is important to gain an understanding of how genetic variation affects evolution. Recent studies have demonstrated that genome-wide association studies that focus on common variants do not reveal the full picture of susceptibility to disease, and that a significant proportion of heritability can be explained by rare variants. It is necessary to conduct additional studies based on sequencing in order to catalog the rare variations that exist across populations around the world and to determine their impact, including gene-by-environment interaction. Environmental Changes The environment can influence species through changing their environment. The famous tale of the peppered moths demonstrates this principle—the moths with white bodies, which were abundant in urban areas where coal smoke blackened tree bark and made them easily snatched by predators while their darker-bodied counterparts prospered under these new conditions. But the reverse is also true: environmental change could influence species' ability to adapt to the changes they face. The human activities have caused global environmental changes and their impacts are largely irreversible. These changes affect biodiversity and ecosystem functions. Additionally they pose significant health risks to humans particularly in low-income countries as a result of polluted water, air soil and food. As an example the increasing use of coal by countries in the developing world such as India contributes to climate change and raises levels of pollution of the air, which could affect the life expectancy of humans. Moreover, human populations are using up the world's finite resources at an ever-increasing rate. This increases the chance that a lot of people will suffer nutritional deficiencies and lack of access to water that is safe for drinking. The impact of human-driven environmental changes on evolutionary outcomes is a complex matter microevolutionary responses to these changes likely to reshape the fitness landscape of an organism. These changes may also change the relationship between a trait and its environmental context. For instance, a study by Nomoto and co. that involved transplant experiments along an altitude gradient showed that changes in environmental signals (such as climate) and competition can alter a plant's phenotype and shift its directional choice away from its historical optimal suitability. It is therefore essential to know how these changes are influencing the microevolutionary response of our time, and how this information can be used to forecast the future of natural populations during the Anthropocene period. This is crucial, as the changes in the environment triggered by humans will have an impact on conservation efforts, as well as our own health and our existence. Therefore, it is essential to continue the research on the relationship between human-driven environmental changes and evolutionary processes at global scale. The Big Bang There are a myriad of theories regarding the universe's development and creation. But none of them are as widely accepted as the Big Bang theory, which is now a standard in the science classroom. The theory provides explanations for a variety of observed phenomena, like the abundance of light-elements, the cosmic microwave back ground radiation, and the vast scale structure of the Universe. In its simplest form, the Big Bang Theory describes how the universe began 13.8 billion years ago in an unimaginably hot and dense cauldron of energy that has continued to expand ever since. The expansion led to the creation of everything that is present today, including the Earth and all its inhabitants. The Big Bang theory is supported by a mix of evidence, which includes the fact that the universe appears flat to us as well as the kinetic energy and thermal energy of the particles that compose it; the temperature fluctuations in the cosmic microwave background radiation; and the abundance of light and heavy elements found in the Universe. The Big Bang theory is also well-suited to the data gathered by particle accelerators, astronomical telescopes and high-energy states. In the early 20th century, physicists held an opinion that was not widely held on the Big Bang. Fred Hoyle publicly criticized it in 1949. After World War II, observations began to surface that tipped scales in favor the Big Bang. Arno Pennzias, Robert Wilson, and others discovered the cosmic background radiation in 1964. This omnidirectional signal is the result of time-dependent expansion of the Universe. The discovery of this ionized radiation, with a spectrum that is in line with a blackbody that is approximately 2.725 K, was a significant turning point for the Big Bang theory and tipped the balance in its favor over the competing Steady State model. The Big Bang is an important element of “The Big Bang Theory,” a popular TV show. Sheldon, Leonard, and the rest of the group employ this theory in “The Big Bang Theory” to explain a variety of observations and phenomena. One example is their experiment which describes how jam and peanut butter are squished.