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The Academy's Evolution Site The concept of biological evolution is a fundamental concept in biology. The Academies have been active for a long time in helping people who are interested in science understand the concept of evolution and how it influences all areas of scientific research. This site provides teachers, students and general readers with a wide range of learning resources about evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD. Tree of Life The Tree of Life is an ancient symbol that represents the interconnectedness of life. It appears in many spiritual traditions and cultures as symbolizing unity and love. It has numerous practical applications as well, including providing a framework for understanding the history of species and how they react to changes in environmental conditions. Early attempts to represent the world of biology were built on categorizing organisms based on their physical and metabolic characteristics. These methods depend on the sampling of different parts of organisms, or DNA fragments, have significantly increased the diversity of a Tree of Life2. However the trees are mostly made up of eukaryotes. Bacterial diversity is not represented in a large way3,4. By avoiding the necessity for direct observation and experimentation, genetic techniques have made it possible to represent the Tree of Life in a more precise way. Particularly, molecular methods enable us to create trees by using sequenced markers like the small subunit ribosomal gene. Despite the massive growth of the Tree of Life through genome sequencing, a large amount of biodiversity remains to be discovered. This is particularly true of microorganisms, which can be difficult to cultivate and are often only found in a single sample5. A recent analysis of all known genomes has produced a rough draft of the Tree of Life, including many archaea and bacteria that have not been isolated and their diversity is not fully understood6. This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, helping to determine whether specific habitats require protection. This information can be used in many ways, including finding new drugs, battling diseases and improving crops. This information is also beneficial for conservation efforts. It helps biologists discover areas most likely to have species that are cryptic, which could have important metabolic functions and be vulnerable to the effects of human activity. While conservation funds are essential, the best method to protect the world's biodiversity is to empower more people in developing countries with the knowledge they need to take action locally and encourage conservation. Phylogeny A phylogeny, also known as an evolutionary tree, shows the relationships between groups of organisms. By using molecular information, morphological similarities and differences or ontogeny (the course of development of an organism), scientists can build a phylogenetic tree which illustrates the evolutionary relationships between taxonomic categories. Phylogeny is crucial in understanding the evolution of biodiversity, evolution and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and evolved from an ancestor with common traits. These shared traits are either homologous or analogous. Homologous traits are similar in their underlying evolutionary path, while analogous traits look similar but do not have the same ancestors. Scientists group similar traits together into a grouping known as a clade. All organisms in a group have a common trait, such as amniotic egg production. They all evolved from an ancestor with these eggs. The clades are then linked to form a phylogenetic branch that can determine the organisms with the closest relationship. Scientists utilize molecular DNA or RNA data to construct a phylogenetic graph that is more precise and precise. This information is more precise and provides evidence of the evolution history of an organism. The use of molecular data lets researchers identify the number of organisms who share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationships between organisms can be affected by a variety of factors including phenotypic plasticity, an aspect of behavior that changes in response to unique environmental conditions. This can cause a trait to appear more similar to one species than another, clouding the phylogenetic signal. However, this issue can be cured by the use of methods such as cladistics which include a mix of homologous and analogous features into the tree. Additionally, phylogenetics can help determine the duration and speed at which speciation occurs. This information can assist conservation biologists in deciding which species to safeguard from the threat of extinction. In the end, it is the preservation of phylogenetic diversity which will create an ecosystem that is balanced and complete. Evolutionary Theory The main idea behind evolution is that organisms change over time due to their interactions with their environment. Many scientists have developed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that a living thing would evolve according to its individual needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern taxonomy system that is hierarchical and Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of certain traits can result in changes that are passed on to the next generation. In the 1930s and 1940s, concepts from a variety of fields—including genetics, natural selection and particulate inheritance—came together to form the current evolutionary theory which explains how evolution is triggered by the variation of genes within a population and how those variations change in time as a result of natural selection. This model, known as genetic drift, mutation, gene flow and sexual selection, is a key element of current evolutionary biology, and can be mathematically explained. Recent discoveries in the field of evolutionary developmental biology have shown the ways in which variation can be introduced to a species via genetic drift, mutations or reshuffling of genes in sexual reproduction and migration between populations. These processes, as well as others, such as directional selection and gene erosion (changes to the frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time, as well as changes in the phenotype (the expression of genotypes within individuals). Incorporating evolutionary thinking into all aspects of biology education could increase students' understanding of phylogeny and evolution. In a recent study by Grunspan and co., it was shown that teaching students about the evidence for evolution increased their acceptance of evolution during a college-level course in biology. For more information on how to teach about evolution, look up The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education. Evolution in Action Traditionally, scientists have studied evolution by studying fossils, comparing species and observing living organisms. Evolution isn't a flims moment; it is an ongoing process. Bacteria evolve and resist antibiotics, viruses evolve and escape new drugs, and animals adapt their behavior in response to a changing planet. The changes that result are often visible. It wasn't until the late 1980s that biologists began to realize that natural selection was at work. The main reason is that different traits result in a different rate of survival and reproduction, and can be passed down from one generation to another. In the past, if one particular allele, the genetic sequence that controls coloration – was present in a group of interbreeding species, it could quickly become more prevalent than the other alleles. Over time, that would mean the number of black moths within a particular population could rise. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. Observing evolutionary change in action is much easier when a species has a rapid turnover of its generation such as bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that are descended from one strain. The samples of each population have been collected regularly, and more than 50,000 generations of E.coli have passed. Lenski's research has revealed that mutations can alter the rate at which change occurs and the effectiveness at which a population reproduces. It also shows evolution takes time, which is difficult for some to accept. Microevolution can be observed in the fact that mosquito genes for resistance to pesticides are more common in populations where insecticides have been used. 에볼루션 코리아 is because the use of pesticides creates a selective pressure that favors individuals who have resistant genotypes. The rapidity of evolution has led to an increasing recognition of its importance especially in a planet which is largely shaped by human activities. This includes pollution, climate change, and habitat loss that prevents many species from adapting. Understanding evolution will help us make better decisions about the future of our planet and the lives of its inhabitants.