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The Academy's Evolution Site Biology is one of the most fundamental concepts in biology. The Academies have been for a long time involved in helping people who are interested in science comprehend the concept of evolution and how it influences all areas of scientific exploration. This site provides a wide range of resources for teachers, students as well as general readers about evolution. It contains the most important video clips from NOVA and the WGBH-produced science programs on DVD. Tree of Life The Tree of Life is an ancient symbol that symbolizes the interconnectedness of life. It appears in many spiritual traditions and cultures as an emblem of unity and love. It also has many practical applications, such as providing a framework to understand the evolution of species and how they react to changes in environmental conditions. The first attempts at depicting the biological world focused on categorizing organisms into distinct categories which had been distinguished by their physical and metabolic characteristics1. These methods, which rely on the sampling of various parts of living organisms or small fragments of their DNA, greatly increased the variety of organisms that could be represented in a tree of life2. These trees are mostly populated by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4. In avoiding the necessity of direct experimentation and observation genetic techniques have allowed us to depict the Tree of Life in a much more accurate way. In particular, molecular methods enable us to create trees by using sequenced markers like the small subunit ribosomal RNA gene. The Tree of Life has been significantly expanded by genome sequencing. However there is a lot of diversity to be discovered. This is particularly true of microorganisms, which are difficult to cultivate and are typically only present in a single specimen5. Recent analysis of all genomes produced an unfinished draft of a Tree of Life. This includes a large number of archaea, bacteria, and other organisms that haven't yet been isolated, or the diversity of which is not fully understood6. This expanded Tree of Life can be used to evaluate the biodiversity of a specific region and determine if specific habitats require special protection. This information can be utilized in a variety of ways, including finding new drugs, battling diseases and improving crops. It is also beneficial for conservation efforts. It helps biologists discover areas that are most likely to be home to species that are cryptic, which could have vital metabolic functions, and could be susceptible to human-induced change. Although funds to protect biodiversity are essential however, the most effective method to protect the world's biodiversity is for more people living in developing countries to be empowered with the knowledge to act locally in order to promote conservation from within. Phylogeny A phylogeny (also called an evolutionary tree) depicts the relationships between species. Using molecular data, morphological similarities and differences or ontogeny (the course of development of an organism), scientists can build a phylogenetic tree that illustrates the evolutionary relationships between taxonomic groups. The role of phylogeny is crucial in understanding the relationship between genetics, biodiversity and evolution. A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms that share similar traits that have evolved from common ancestral. These shared traits can be either analogous or homologous. Homologous traits share their evolutionary roots, while analogous traits look like they do, but don't have the identical origins. Scientists combine similar traits into a grouping referred to as a the clade. Every organism in a group have a common characteristic, for example, amniotic egg production. They all evolved from an ancestor who had these eggs. The clades are then connected to form a phylogenetic branch to identify organisms that have the closest relationship to. Scientists make use of DNA or RNA molecular data to create a phylogenetic chart that is more precise and precise. This information is more precise and gives evidence of the evolutionary history of an organism. Researchers can use Molecular Data to estimate the age of evolution of organisms and determine how many organisms have a common ancestor. The phylogenetic relationships of organisms are influenced by many factors, including phenotypic plasticity a kind of behavior that alters in response to unique environmental conditions. This can cause a characteristic to appear more similar to one species than another and obscure the phylogenetic signals. This problem can be mitigated by using cladistics. This is a method that incorporates an amalgamation of analogous and homologous features in the tree. In 무료에볼루션 , phylogenetics helps determine the duration and rate of speciation. This information can aid conservation biologists to make decisions about which species they should protect from the threat of extinction. It is ultimately the preservation of phylogenetic diversity which will lead to a complete and balanced ecosystem. Evolutionary Theory The central theme of evolution is that organisms develop distinct characteristics over time as a result of their interactions with their surroundings. Many scientists have come up with theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism would evolve according to its individual requirements, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical system of taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of traits can cause changes that are passed on to the next generation. In the 1930s & 1940s, ideas from different fields, including natural selection, genetics & particulate inheritance, were brought together to form a modern theorizing of evolution. This defines how evolution occurs by the variation of genes in the population, and how these variations change over time as a result of natural selection. This model, which encompasses mutations, genetic drift in gene flow, and sexual selection can be mathematically described. Recent discoveries in the field of evolutionary developmental biology have shown that genetic variation can be introduced into a species via mutation, genetic drift and reshuffling genes during sexual reproduction, and also through the movement of populations. These processes, as well as others such as directional selection or genetic erosion (changes in the frequency of the genotype over time) can lead to evolution which is defined by change in the genome of the species over time, and also the change in phenotype over time (the expression of the genotype within the individual). Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all aspects of biology. A recent study conducted by Grunspan and colleagues, for example demonstrated that teaching about the evidence that supports evolution increased students' acceptance of evolution in a college-level biology course. For more details on how to teach evolution read The Evolutionary Potential in all Areas of Biology or Thinking Evolutionarily as a Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Scientists have traditionally looked at evolution through the past—analyzing fossils and comparing species. 에볼루션 슬롯게임 study living organisms. Evolution is not a past moment; it is an ongoing process that continues to be observed today. Viruses evolve to stay away from new medications and bacteria mutate to resist antibiotics. Animals adapt their behavior as a result of the changing environment. The changes that result are often evident. It wasn't until the late 1980s that biologists began to realize that natural selection was at work. The key is that various traits confer different rates of survival and reproduction (differential fitness), and can be transferred from one generation to the next. In the past, if one particular allele – the genetic sequence that determines coloration—appeared in a group of interbreeding organisms, it could quickly become more common than other alleles. As time passes, this could mean that the number of moths with black pigmentation may increase. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. It is easier to observe evolutionary change when the species, like bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from one strain. The samples of each population were taken frequently and more than 500.000 generations of E.coli have been observed to have passed. Lenski's research has revealed that mutations can drastically alter the efficiency with which a population reproduces—and so the rate at which it changes. It also shows evolution takes time, which is difficult for some to accept. Another example of microevolution is the way mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides are employed. This is because pesticides cause a selective pressure which favors individuals who have resistant genotypes. The speed of evolution taking place has led to an increasing recognition of its importance in a world that is shaped by human activity—including climate change, pollution, and the loss of habitats that hinder many species from adjusting. Understanding evolution can help us make smarter choices about the future of our planet as well as the lives of its inhabitants.