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The Berkeley Evolution Site Students and teachers who explore the Berkeley site will find resources to help them understand and teach evolution. The resources are organized into different learning paths for example “What does T. rex look like?” Charles Darwin's theory of natural selection explains that over time, animals that are more able to adapt to changing environments thrive, and those that don't become extinct. Science is all about the process of biological evolution. What is Evolution? The word evolution has many nonscientific meanings, including “progress” or “descent with modification.” Scientifically, it refers to a changes in the traits of living things (or species) over time. The reason for this change is biological terms on natural drift and selection. Evolution is one of the fundamental tenets of modern biology. It is an accepted theory that has stood the test of time and thousands of scientific experiments. Contrary to other theories of science like the Copernican theory or the germ theory of disease, the evolution theory does not address issues of spiritual belief or the existence of God. Early evolutionists, including Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical characteristics were predetermined to change, in a step-wise manner, over time. 에볼루션 블랙잭 was called the “Ladder of Nature”, or scala Naturae. Charles Lyell first used this term in 1833 in his Principles of Geology. Darwin revealed his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It asserts that different species of organisms have the same ancestry, which can be determined through fossils and other lines of evidence. This is the current view of evolution that is supported by many lines of scientific research that include molecular genetics. While scientists don't know the exact mechanism by which organisms evolved, they are confident that the evolution of life on earth is the result of natural selection and genetic drift. People with traits that are advantageous are more likely to live and reproduce, and these individuals transmit their genes to the next generation. As time passes the gene pool slowly changes and develops into new species. Some scientists employ the term”evolution” to refer to large-scale changes, like the formation of an animal from an ancestral one. Others, like population geneticists, define the term “evolution” more broadly by referring to a net change in the frequency of alleles across generations. Both definitions are valid and reliable however some scientists believe that the allele-frequency definition omits important features of the evolutionary process. Origins of Life A key step in evolution is the emergence of life. This occurs when living systems begin to develop at the micro level, within individual cells, for instance. The origins of life is an issue in a variety of disciplines such as biology, chemistry, and geology. The nature of life is an area that is of immense interest to scientists 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 things was called “spontaneous generation” or “spontaneous evolutionary”. This was a popular belief prior to Louis Pasteur's tests proved that the creation of living organisms was not possible by the natural process. Many scientists believe it is possible to transition from living to nonliving substances. However, the conditions needed are extremely difficult to replicate in a laboratory. Researchers studying the nature of life are also keen to understand the physical properties of early Earth and other planets. The growth of life is dependent on a number of complex chemical reactions which are not predicted by the basic physical laws. These include the transformation of long information-rich molecules (DNA or RNA) into proteins that carry out functions and the replication of these intricate molecules to create new DNA or RNA sequences. These chemical reactions can be compared to a chicken-and egg problem which is the development and emergence of DNA/RNA, the protein-based cell machinery, is essential for the onset life. Although, without life, the chemistry required to enable it does appear to work. Abiogenesis research requires collaboration among scientists from various fields. This includes prebiotic chemists, astrobiologists, planetary scientists geophysicists, geologists, and geophysicists. Evolutionary Changes The term “evolution” is typically used to refer to the accumulated changes in the genetic traits of an entire population over time. These changes can result from adaptation to environmental pressures as explained in the article on Darwinism (see the entry on Charles Darwin for background) or may result from natural selection. This mechanism also increases the number of genes that confer the advantage of survival for an animal, resulting in an overall change in the appearance of a group. The specific mechanisms that cause these evolutionary changes include mutation or reshuffling genes during sexual reproduction, as well as gene flow between populations. While reshuffling and mutation of genes occur in all living organisms and the process by which beneficial mutations become more common is called natural selection. This is because, as mentioned above those with the beneficial trait tend to have a higher reproductive rate than those with it. This differential in the number of offspring produced over a number of generations could result in a gradual shift in the average number of beneficial characteristics in a group. This is evident in the evolution of various beak shapes on finches from the Galapagos Islands. They have created these beaks to ensure that they can access food more easily in their new environment. These changes in the shape and form of organisms could also be a catalyst for the creation of new species. Most of the changes that take place are the result of a single mutation, but occasionally several will happen at once. The majority of these changes are not harmful or even harmful to the organism however, a small proportion of them can have a positive impact on survival and reproduction, thus increasing their frequency in the population over time. This is the mechanism of natural selection and it could be a time-consuming process that produces the cumulative changes that eventually result in a new species. Some people confuse the idea of evolution with the notion that the traits inherited from parents can be altered by conscious choice, or through use and abuse, which is called soft inheritance. This is a misinterpretation of the nature of evolution and of the actual biological processes that trigger it. A more precise description is that evolution involves a two-step process, which involves the separate and often conflicting forces of natural selection and mutation. Origins of Humans Modern humans (Homo Sapiens) evolved from primates, which is a group of mammal species which includes chimpanzees as well as gorillas. Our ancestral ancestors were walking on two legs, as demonstrated by the first fossils. Genetic and biological similarities suggest that we share the same ancestry with Chimpanzees. In actual fact we are the closest connected to chimpanzees belonging to the Pan Genus which includes bonobos and pygmy chimpanzees. The last common ancestor between modern humans and chimpanzees was between 8 and 6 million years old. As time has passed, humans have developed a number of characteristics, such as bipedalism and the use fire. They also created advanced tools. It's only in the last 100,000 years that we have developed the majority of our important characteristics. They include language, a large brain, the ability to create and utilize complex tools, as well as the ability to adapt to cultural differences. The process of evolution occurs when genetic changes enable members of the group to better adapt to the environment. Natural selection is the mechanism that drives this change. Certain characteristics are more desirable than others. Those with the better adaptations are more likely to pass on their genes to the next generation. This is the way all species evolve and the basis for the theory of evolution. Scientists refer to it as the “law of natural selection.” The law states that species that have a common ancestor, tend to develop similar traits over time. This is because these traits allow them to live and reproduce in their environment. Every organism has DNA molecules, which contains the information needed to guide their growth and development. The DNA molecule is made up of base pairs that are arranged in a spiral around phosphate molecules and sugar molecules. The sequence of bases within each strand determines phenotype or the individual's unique appearance and behavior. Variations in a population can be caused by mutations and reshufflings in genetic material (known collectively as alleles). Fossils from the early human species Homo erectus, as well as Homo neanderthalensis have been found in Africa, Asia and Europe. These fossils, despite variations in their appearance, all support the idea that modern humans' ancestors originated in Africa. The fossil evidence and genetic evidence suggest that early humans came from Africa into Asia and then Europe.