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Evolution Explained The most fundamental idea is that living things change in time. These changes could aid the organism in its survival or reproduce, or be better adapted to its environment. Scientists have employed genetics, a brand new science to explain how evolution occurs. They also have used physical science to determine the amount of energy required to trigger these changes. Natural Selection To allow evolution to occur organisms must be able to reproduce and pass their genetic traits on to the next generation. Natural selection is sometimes called “survival for the strongest.” However, the phrase could be misleading as it implies that only the strongest or fastest organisms can survive and reproduce. The most well-adapted organisms are ones that can adapt to the environment they live in. Environmental conditions can change rapidly, and if the population isn't well-adapted to the environment, it will not be able to survive, leading to a population shrinking or even becoming extinct. The most fundamental component of evolution is natural selection. It occurs when beneficial traits are more prevalent as time passes which leads to the development of new species. This process is driven primarily by heritable genetic variations of organisms, which are a result of sexual reproduction. Any force in the environment that favors or hinders certain characteristics could act as an agent of selective selection. These forces could be physical, like temperature, or biological, like predators. Over time populations exposed to various agents are able to evolve differently that no longer breed together and are considered separate species. Although the concept of natural selection is simple however, it's not always clear-cut. Even among scientists and educators, there are many misconceptions about the process. Surveys have revealed that there is a small correlation between students' understanding of evolution and their acceptance of the theory. Brandon's definition of selection is confined to differential reproduction and does not include inheritance. Havstad (2011) is one of the many authors who have argued 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 variety of instances in which a trait increases its proportion in a population, but does not increase the rate at which people who have the trait reproduce. These situations might not be categorized in the narrow sense of natural selection, however they could still be in line with Lewontin's requirements for a mechanism such as this to operate. For instance parents with a particular trait may produce more offspring than those without it. Genetic Variation Genetic variation refers to the differences in the sequences of genes that exist between members of the same species. It is this variation that enables natural selection, which is one of the primary forces that drive evolution. Mutations or the normal process of DNA changing its structure during cell division could result in variations. Different gene variants may result in a variety of traits like eye colour fur type, eye colour or the ability to adapt to changing environmental conditions. If a trait is advantageous it will be more likely to be passed down to the next generation. This is referred to as an advantage that is selective. A particular type of heritable change is phenotypic plasticity, which allows individuals to alter their appearance and behaviour in response to environmental or stress. Such changes may help them survive in a new habitat or take advantage of an opportunity, for example by increasing the length of their fur to protect against cold or changing color to blend in with a specific surface. These phenotypic variations don't alter the genotype and therefore are not thought of as influencing evolution. Heritable variation is vital to evolution since it allows for adaptation to changing environments. It also enables natural selection to work, by making it more likely that individuals will be replaced by individuals with characteristics that are suitable for the environment in which they live. In some cases however the rate of variation transmission to the next generation might not be enough for natural evolution to keep up with. Many harmful traits such as genetic diseases persist in populations despite their negative effects. This is partly because of a phenomenon called reduced penetrance, which implies that some individuals with the disease-related gene variant do not exhibit any symptoms or signs of the condition. Other causes include gene by environment interactions and non-genetic factors such as lifestyle eating habits, diet, and exposure to chemicals. In order to understand the reason why some harmful traits do not get eliminated through natural selection, it is important to gain an understanding of how genetic variation influences the evolution. Recent studies have demonstrated that genome-wide association studies focusing on common variations fail to capture the full picture of susceptibility to disease, and that a significant percentage of heritability is attributed to rare variants. It is necessary to conduct additional sequencing-based studies to document rare variations across populations worldwide and determine their impact, including gene-by-environment interaction. Environmental Changes While natural selection influences evolution, the environment influences species by changing the conditions in which they live. The famous story of peppered moths demonstrates this principle—the moths with white bodies, prevalent in urban areas where coal smoke had blackened tree bark and made them easily snatched by predators while their darker-bodied counterparts prospered under these new conditions. The opposite is also the case that environmental changes can affect species' capacity to adapt to changes they face. Human activities are causing environmental change at a global level and the consequences of these changes are irreversible. These changes affect biodiversity and ecosystem functions. Additionally, they are presenting significant health risks to the human population especially in low-income countries as a result of polluted water, air, soil and food. For example, the increased use of coal by developing nations, such as India is a major contributor to climate change as well as increasing levels of air pollution that threaten the human lifespan. The world's finite natural resources are being used up at a higher rate by the population of humans. This increases the chance that many people will be suffering from nutritional deficiency as well as lack of access to water that is safe for drinking. The impact of human-driven environmental changes on evolutionary outcomes is a complex matter, with microevolutionary responses to these changes likely to reshape the fitness landscape of an organism. These changes can also alter the relationship between a particular characteristic and its environment. try this et. and. showed, for example, that environmental cues, such as climate, and competition, can alter the characteristics of a plant and shift its choice away from its historical optimal match. It is important to understand the way in which these changes are influencing microevolutionary reactions of today and how we can use this information to predict the future of natural populations during the Anthropocene. This is important, because the changes in the environment triggered by humans will have a direct effect on conservation efforts, as well as our health and well-being. It is therefore vital to continue to study the relationship between human-driven environmental changes and evolutionary processes on global scale. The Big Bang There are several theories about the origin and expansion of the Universe. However, none of them is as widely accepted as the Big Bang theory, which is now a standard in the science classroom. The theory provides a wide variety of observed phenomena, including the abundance of light elements, cosmic microwave background radiation as well as the large-scale structure of the Universe. The Big Bang Theory is a simple explanation of the way in which the universe was created, 13.8 billions years ago as a massive and unimaginably hot cauldron. Since then it has expanded. This expansion has shaped everything that is present today, including the Earth and all its inhabitants. The Big Bang theory is widely supported by a combination of evidence, including the fact that the universe appears flat to us; 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 heavy and light elements that are found in the Universe. The Big Bang theory is also suitable for the data collected by particle accelerators, astronomical telescopes and high-energy states. In the early 20th century, physicists had an unpopular view of the Big Bang. In 1949, astronomer Fred Hoyle publicly dismissed it as “a fantasy.” After World War II, observations began to emerge that tilted scales in favor the Big Bang. In 1964, Arno Penzias and Robert Wilson serendipitously discovered the cosmic microwave background radiation, an omnidirectional sign in the microwave band that is the result of the expansion of the Universe over time. The discovery of this ionized radiation that has a spectrum that is consistent with a blackbody that is approximately 2.725 K, was a major turning point in the Big Bang theory and tipped the balance to its advantage over the rival Steady State model. The Big Bang is a major element of the popular TV show, “The Big Bang Theory.” In the show, Sheldon and Leonard make use of this theory to explain a variety of phenomenons and observations, such as their research on how peanut butter and jelly become combined.