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The Berkeley Evolution Site Students and teachers who explore the Berkeley site will find resources to assist them in understanding and teaching evolution. The materials are arranged into different learning paths such as “What did T. rex taste like?” Charles Darwin's theory of natural selection explains how creatures that are better equipped to adapt biologically to a changing environment survive over time and those who do not become extinct. This process of evolution in biology is the basis of science. What is Evolution? The term “evolution” can have many nonscientific meanings, such as “progress” or “descent with modification.” It is an academic term that is used to describe the process of changing characteristics over time in organisms or species. This change is based in biological terms on natural drift and selection. Evolution is a fundamental tenet in modern biology. It is a theory that has been verified by a myriad of scientific tests. In contrast to other theories in science such as the Copernican theory or the germ theory of disease, the evolution theory does not address questions of religious belief or God's existence. 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 way, over time. This was referred to as the “Ladder of Nature”, or scala Naturae. Charles Lyell used the term to describe this concept in his Principles of Geology, first published in 1833. In Read Even more , Darwin formulated his theory of evolution and published it in his book On the Origin of Species. It states that all 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, and is supported by a variety of research lines in science, including molecular genetics. Although scientists aren't able to determine exactly how organisms developed, they are confident that the evolution of life on earth is the result of natural selection and genetic drift. Individuals with advantageous characteristics are more likely than others to survive and reproduce. They pass on their genes on to the next generation. Over time, this results in an accumulation of changes in the gene pool that gradually create new species and types. Some scientists also use the term”evolution” to describe large-scale evolutionary changes like the creation of the new species from an ancestral species. Other scientists, like population geneticists, define evolution more broadly by referring the net variation in the frequency of alleles over generations. Both definitions are accurate and palatable, but some scientists believe that allele-frequency definitions miss important aspects of the evolution. Origins of Life The birth of life is an essential step in the process of evolution. The beginning of life takes place when living systems begin to develop at a microscopic level, such as within cells. The origins of life are an important issue in a variety of disciplines that include biology and chemistry. The nature of life is an area of great interest in science because it challenges the theory of evolution. It is often referred to as “the mystery of life” or “abiogenesis.” The idea that life could be born from non-living things was called “spontaneous generation” or “spontaneous evolutionary”. It was a popular belief prior to Louis Pasteur's tests proved that the emergence of living organisms was not possible through an organic process. Many scientists believe it is possible to move from living to nonliving substances. The conditions necessary for the creation of life are difficult to replicate in a laboratory. Researchers interested in the evolution and origins of life are also eager to understand the physical properties of the early Earth as well as other planets. In addition, the development of life depends on the sequence of extremely complex chemical reactions that can't be predicted from basic physical laws on their own. These include the reading of long, information-rich molecules (DNA or RNA) into proteins that carry out some function and the replication of these intricate molecules to produce new DNA or RNA sequences. These chemical reactions are comparable to the chicken-and-egg issue that is the emergence and growth of DNA/RNA, protein-based cell machinery, is required to begin the process of becoming a living organism. Although without life, the chemistry that is required to make it possible is working. Research in the area of abiogenesis requires collaboration among scientists from various disciplines. This includes prebiotic scientists, astrobiologists, and planet scientists. Evolutionary Changes The term “evolution” is commonly used to describe the accumulated changes in genetic characteristics of populations over time. 에볼루션 카지노 may result from adaptation to environmental pressures, as described in the entry on Darwinism (see the entry on Charles Darwin for background) or may result from natural selection. This process increases the frequency of genes that offer the advantage of survival for the species, leading to an overall change in the appearance of a group. The specific mechanisms behind these changes in evolutionary process include mutation or reshuffling genes during sexual reproduction, and gene flow between populations. Natural selection is the process that makes beneficial mutations more common. All organisms undergo changes and reshuffles of their genes. As noted above, individuals with the beneficial trait have a higher reproduction rate than those who don't. This differential in the number of offspring born over a long period of time can result in a gradual shift in the number of advantageous traits within the group. One good example is the increase in beak size on different species of finches in the Galapagos Islands, which have developed different beak shapes to allow them to more easily access food in their new environment. These changes in form and shape can also help create new organisms. The majority of the changes that occur are the result of a single mutation, but occasionally several will happen simultaneously. Most of these changes may be harmful or neutral however, a few may have a positive effect on the survival of the species and reproduce with increasing frequency over time. This is the process of natural selection and it can, over time, produce the cumulative changes that eventually result in a new species. Many people confuse the concept of evolution with the idea that traits inherited can be changed through conscious choice or 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. It is more accurate to say that the process of evolution is a two-step independent process that involves the forces of natural selection as well as mutation. Origins of Humans Modern humans (Homo sapiens) evolved from primates, a group of mammals that also includes chimpanzees, gorillas, and bonobos. The earliest human fossils indicate that our ancestors were bipeds, walkers on two legs. Genetic and biological similarities show that we have an intimate relationship with Chimpanzees. In fact our closest relatives are chimpanzees belonging to the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor of modern humans and chimpanzees was between 8 and 6 million years ago. Humans have developed a range of traits over time, including bipedalism, the use of fire and advanced tools. However, it is only in the past 100,000 years or so that the majority of the traits that distinguish us from other species have emerged. These include language, large brain, the capacity to build and use complex tools, and the diversity of our culture. Evolution happens when genetic changes allow members of a population to better adapt to their environment. This adaptation is driven by natural selection, a process whereby certain traits are more desirable than other traits. The better adapted are more likely to pass their genes on to the next generation. This is how all species evolve and is the basis for the theory of evolution. Scientists refer to this as the “law of natural selection.” The law states that species which have an ancestor in common will tend to develop similar traits as time passes. This is because the characteristics make it easier for them to survive and reproduce in their environments. All organisms have a DNA molecule that provides the information necessary to control their growth and development. The structure of DNA is composed of base pairs which are arranged in a spiral, around sugar and phosphate molecules. The sequence of bases within each strand determines the phenotype, or the individual's characteristic appearance and behavior. Variations in a population are caused by reshufflings and mutations of genetic material (known collectively as alleles). Fossils from the earliest human species Homo erectus, as well as Homo neanderthalensis have been discovered in Africa, Asia and Europe. Although there are some differences, these fossils all support the hypothesis that modern humans first came into existence in Africa. Evidence from fossils and genetics suggest that early humans moved from Africa into Asia and then Europe.