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에볼루션 무료체험 SiteThe Berkeley site has resources that can help students and educators understand and teach evolution. The materials are arranged in different learning paths like "What does T. rex look like?"Charles Darwin's theory on natural selection explains how creatures who are better equipped to adapt biologically to a changing environments over time, and those that don't disappear. This process of evolution is what science is all about.What is Evolution?The term "evolution" could have a variety of meanings that are not scientific. For example it could mean "progress" and "descent with modifications." It is an academic term that refers to the process of changing characteristics in a species or species. This change is based in biological terms on natural drift and selection.Evolution is a central tenet of modern biology. It is a theory that has been verified through thousands of scientific tests. Contrary to other theories of science such as the Copernican theory or the germ theory of disease, evolution does not address issues of spiritual belief or the existence of God.Early evolutionists, like Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather), believed that certain physical traits were predetermined to change, in a step-wise manner, as time passes. This was known as the "Ladder of Nature" or scala naturae. Charles Lyell used the term to describe this idea in his Principles of Geology, first published in 1833.Darwin revealed his theory of evolution in his book On the Origin of Species, written in the early 1800s. It asserts that different species of organisms have a common ancestry, which can be determined through fossils and other evidence. This is the modern view of evolution, and is supported by many lines of research in science, including molecular genetics.While scientists do not know the exact mechanism by which organisms evolved however they are sure that the evolution of life on earth is a result of natural selection and genetic drift. People with traits that are advantageous are more likely to survive and reproduce, and these individuals transmit their genes to the next generation. In time this leads to a gradual accumulation of changes to the gene pool, which eventually create new species and types.Certain scientists also use the term evolution to describe large-scale evolutionary changes, such as the formation of a new species from an ancestral species. Other scientists, such as population geneticists, define evolution more broadly by referring to a net variation in the frequency of alleles over generations. Both definitions are acceptable and accurate, although some scientists argue that the allele-frequency definition is missing crucial aspects of the evolutionary process.Origins of LifeA key step in evolution is the emergence of life. The emergence of life happens when living systems begin to develop at a micro level, like within individual cells.The origin of life is a topic in many disciplines such as biology, chemistry, and geology. The origin of life is a subject of interest in science because it challenges the theory of evolution. It is often called "the mystery of life," or "abiogenesis."The notion that life could emerge from non-living objects was referred to as "spontaneous generation" or "spontaneous evolutionary". This was a common belief prior to Louis Pasteur's tests showed that the development of living organisms was not possible by the natural process.Many scientists still believe it is possible to go from nonliving materials to living. The conditions required to make life are not easy to replicate in a laboratory. Researchers investigating the origins of life are also interested in understanding the physical properties of the early Earth and other planets.The life-cycle of a living organism is also dependent on a series of complex chemical reactions, that are not predicted by the basic physical laws. These include the reading and re-reading of complex molecules, like DNA or RNA, to produce proteins that perform a particular function. These chemical reactions can be compared to the chicken-and-egg issue which is the development and emergence of DNA/RNA, a protein-based cell machinery, is necessary to begin the process of becoming a living organism. Although without life, the chemistry required to create it does appear to work.Abiogenesis research requires collaboration with researchers from different disciplines. This includes prebiotic chemists, the astrobiologists, the planet scientists geophysicists and geologists.Evolutionary ChangesThe term "evolution" is typically used to describe the cumulative changes in the genetic traits of populations over time. These changes may be the result of the adaptation to environmental pressures as discussed in Darwinism.This is a process that increases the frequency of those genes in a species that offer an advantage in survival over others which results in a gradual change in the overall appearance of a particular population. The specific mechanisms responsible for these evolutionary changes are mutation, reshuffling of genes during sexual reproduction, and also gene flow between populations.While reshuffling and mutation of genes happen in all organisms The process through which beneficial mutations become more common is referred to as natural selection. This happens because, as noted above those with the beneficial trait tend to have a higher fertility rate than those with it. Over the course of many generations, this variation in the numbers of offspring born could result in a gradual shift in the average amount of desirable traits within a group of.An excellent example is the growing beak size on different species of finches on the Galapagos Islands, which have developed different beak shapes that allow them to easily access food in their new habitat. These changes in the form and shape of organisms could also aid in the creation of new species.The majority of changes are caused by a single mutation, but sometimes several occur at once. Most of these changes are not harmful or even harmful to the organism but a small percentage can be beneficial to survival and reproduction, thus increasing the frequency of these changes in the population over time. This is the way of natural selection, and it is able to, over time, produce the gradual changes that ultimately lead to the creation of a new species.Many people mistakenly associate evolution with the concept of soft inheritance, which is the idea that traits inherited from parents can be altered by conscious choice or abuse. This is a misunderstood understanding of the nature of evolution, and of the actual biological processes that cause it. It is more precise to say that evolution is a two-step, separate process that involves the forces of natural selection as well as mutation.Origins of HumansModern humans (Homo sapiens) evolved from primates, a group of mammals that also includes gorillas, chimpanzees, and bonobos. Our ancestors walked on two legs, as evidenced by the first fossils. Biological and genetic similarities indicate that we have a close relationship with the chimpanzees. In fact we are the closest connected to chimpanzees belonging to the Pan Genus, which includes pygmy chimpanzees and bonobos. The last common human ancestor as well as chimpanzees was born between 8 and 6 million years ago.Over time, humans have developed a variety of traits, including bipedalism and the use of fire. They also invented advanced tools. It is only within the last 100,000 years that we have developed the majority of our important traits. These include language, large brain, the capacity to construct and use sophisticated tools, and a the diversity of our culture.The process of evolution occurs when genetic changes allow members of a population to better adapt to their environment. This adaptation is driven by natural selection, a process that determines certain traits are preferred over others. The ones who are better adapted are more likely to pass on their genes to the next generation. This is the way all species evolve and the basis of the theory of evolution.Scientists call this the "law of natural selection." The law states species that share an ancestor will tend to acquire similar traits as time passes. This is because these traits allow them to live and reproduce in their natural environment.Every living thing has a DNA molecule, which contains the information needed to direct their growth and development. The structure of DNA is composed of base pair arranged in a spiral around phosphate and sugar molecules. The sequence of bases within each strand determines phenotype or the individual's unique appearance and behavior. The variations in a population are caused by mutations and reshufflings in genetic material (known collectively as alleles).Fossils from the early human species Homo erectus, and Homo neanderthalensis have been discovered in Africa, Asia and Europe. These fossils, despite differences in their appearance all support the theory of modern humans' origins in Africa. The evidence from fossils and genetics suggests that the first humans left Africa and migrated to Asia and Europe.