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Evolution Explained The most fundamental notion is that all living things change as they age. These changes can assist the organism to live, reproduce or adapt better to its environment. Scientists have used the new science of genetics to describe how evolution functions. They also have used physics to calculate the amount of energy required to trigger these changes. Natural Selection To allow evolution to occur for organisms to be capable of reproducing and passing their genetic traits on to future generations. This is known as natural selection, which is sometimes described as “survival of the most fittest.” However, the term “fittest” could be misleading because it implies that only the strongest or fastest organisms can survive and reproduce. In reality, the most species that are well-adapted are able to best adapt to the environment they live in. Environmental conditions can change rapidly, and if the population isn't properly adapted to its environment, it may not survive, leading to a population shrinking or even disappearing. The most fundamental element of evolutionary change is natural selection. This happens when phenotypic traits that are advantageous are more prevalent in a particular population over time, resulting in the evolution of new species. This process is driven by the genetic variation that is heritable of living organisms resulting from sexual reproduction and mutation as well as competition for limited resources. Any element in the environment that favors or disfavors certain traits can act as a selective agent. These forces could be biological, such as predators or physical, such as temperature. Over time, populations exposed to different selective agents may evolve so differently that they do not breed together and are considered to be separate species. Although the concept of natural selection is simple however, it's not always clear-cut. Uncertainties about the process are widespread even among scientists and educators. Surveys have shown that students' levels of understanding of evolution are only weakly related to their rates of acceptance of the theory (see references). Brandon's definition of selection is restricted to differential reproduction, and does not include inheritance. However, several authors, including Havstad (2011) and Havstad (2011), have suggested that a broad notion of selection that captures the entire Darwinian process is adequate to explain both speciation and adaptation. There are instances when the proportion of a trait increases within the population, but not in the rate of reproduction. These instances may not be classified in the narrow sense of natural selection, but they may still meet Lewontin’s conditions for a mechanism similar to this to work. For example, parents with a certain trait could have more offspring than those without it. Genetic Variation Genetic variation refers to the differences between the sequences of the genes of members of a specific species. It is the variation that allows natural selection, which is one of the primary forces driving evolution. Mutations or the normal process of DNA rearranging during cell division can cause variations. Different gene variants could result in different traits, such as the color of eyes fur type, eye colour, or the ability to adapt to changing environmental conditions. If a trait is advantageous it is more likely to be passed down to the next generation. This is known as a selective advantage. Phenotypic plasticity is a particular kind of heritable variant that allow individuals to alter their appearance and behavior in response to stress or the environment. These changes can help them to survive in a different environment or take advantage of an opportunity. For instance, they may 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 considered to have contributed to evolution. Heritable variation is vital to evolution since it allows for adapting to changing environments. Natural selection can also be triggered by heritable variation as it increases the likelihood that people with traits that are favorable to a particular environment will replace those who do not. In certain instances however the rate of variation transmission to the next generation may not be sufficient for natural evolution to keep pace with. Many harmful traits, such as genetic diseases, persist in the population despite being harmful. This is mainly due to a phenomenon known as reduced penetrance, which means that some individuals with the disease-associated gene variant do not exhibit any 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. To understand why some harmful traits do not get eliminated by natural selection, it is necessary to gain a better understanding of how genetic variation affects the evolution. Recent studies have demonstrated that genome-wide associations that focus on common variants don't capture the whole picture of disease susceptibility and that rare variants account for an important portion of heritability. It is essential to conduct additional research using sequencing to document rare variations across populations worldwide and determine their effects, including gene-by environment interaction. Environmental Changes The environment can influence species by altering their environment. The well-known story of the peppered moths illustrates this concept: the moths with white bodies, prevalent in urban areas where coal smoke smudges 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 change can alter species' capacity to adapt to the changes they encounter. Human activities cause global environmental change and their effects are irreversible. These changes impact biodiversity globally and ecosystem functions. In addition they pose significant health risks to humans, especially in low income countries, because of pollution of 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 increases levels of pollution of the air, which could affect the life expectancy of humans. The world's scarce natural resources are being consumed at an increasing rate by the human population. This increases the likelihood that a lot of 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 complex, with microevolutionary responses to these changes likely to reshape the fitness environment of an organism. These changes can also alter the relationship between a trait and its environmental context. Nomoto and. al. demonstrated, for instance, that environmental cues like climate and competition can alter the phenotype of a plant and shift its choice away from its historic optimal fit. It is therefore important to understand how these changes are shaping contemporary microevolutionary responses, and how this information can be used to predict the fate of natural populations in the Anthropocene timeframe. This is crucial, as the changes in the environment triggered by humans will have a direct effect on conservation efforts, as well as our own health and existence. This is why it is vital to continue to study the relationship between human-driven environmental changes and evolutionary processes at an international level. The Big Bang There are several theories about the origin and expansion of the Universe. But none of them are as well-known as the Big Bang theory, which has become a commonplace 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. The Big Bang Theory is a simple explanation of how the universe began, 13.8 billions years ago, as a dense and extremely hot cauldron. Since then, it has expanded. This expansion created all that exists today, such as the Earth and all its inhabitants. This theory is backed by a myriad of evidence. These include the fact that we perceive the universe as flat, the thermal and kinetic energy of its particles, the variations in temperature of the cosmic microwave background radiation and the densities and abundances of heavy and lighter elements 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 years of the 20th century, the Big Bang was a minority opinion among scientists. In 에볼루션코리아 dismissed it as “a fantasy.” After World War II, observations began to emerge that tilted scales in favor of the Big Bang. In 1964, Arno Penzias and Robert Wilson serendipitously discovered the cosmic microwave background radiation, a omnidirectional signal in the microwave band that is the result of the expansion of the Universe over time. The discovery of the ionized radioactivity with an apparent spectrum that is in line with a blackbody, at about 2.725 K was a major pivotal moment for the Big Bang Theory and tipped it in its favor against the competing Steady state model. The Big Bang is an important element of “The Big Bang Theory,” the popular television show. Sheldon, Leonard, and the rest of the team use this theory in “The Big Bang Theory” to explain a variety of phenomena and observations. One example is their experiment which describes how peanut butter and jam are mixed together.