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The Academy's Evolution Site Biology is a key concept in biology. The Academies have been for a long time involved in helping those interested in science understand the concept of evolution and how it permeates every area of scientific inquiry. This site provides students, teachers and general readers with a variety of educational resources on evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is an emblem of love and unity in many cultures. It also has important practical applications, like providing a framework to understand the history of species and how they respond to changes in environmental conditions. Early attempts to describe the biological world were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which relied on sampling of different parts of living organisms, or small fragments of their DNA, significantly increased the variety that could be included in a tree of life2. However these trees are mainly comprised of eukaryotes, and bacterial diversity is still largely unrepresented3,4. Genetic techniques have greatly broadened our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. We can create trees by using molecular methods such as the small subunit ribosomal gene. Despite the rapid growth of the Tree of Life through genome sequencing, a large amount of biodiversity awaits discovery. This is especially the case for microorganisms which are difficult to cultivate and are typically found in one sample5. A recent analysis of all genomes resulted in an unfinished draft of the Tree of Life. This includes a wide range of archaea, bacteria and other organisms that have not yet been isolated or whose diversity has not been fully understood6. 에볼루션 바카라 무료체험 expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if specific habitats require special protection. This information can be utilized in a variety of ways, such as finding new drugs, battling diseases and enhancing crops. The information is also incredibly useful to conservation efforts. It can aid biologists in identifying areas most likely to have cryptic species, which may perform important metabolic functions, and could be susceptible to changes caused by humans. While funds to protect biodiversity are essential, the best method to protect the biodiversity of the world is to equip more people in developing countries with the information they require to act locally and promote conservation. Phylogeny A phylogeny (also known as an evolutionary tree) depicts the relationships between organisms. Scientists can create a phylogenetic chart that shows the evolution of taxonomic groups using molecular data and morphological differences or similarities. The role of phylogeny is crucial in understanding genetics, biodiversity and evolution. A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms that have similar traits and have evolved from an ancestor with common traits. These shared traits could be analogous, or homologous. Homologous traits are similar in their evolutionary paths. Analogous traits might appear similar, but they do not have the same origins. Scientists put similar traits into a grouping referred to as a Clade. All members of a clade share a characteristic, for example, amniotic egg production. They all evolved from an ancestor who had these eggs. The clades are then connected to create a phylogenetic tree to determine which organisms have the closest connection to each other. Scientists make use of molecular DNA or RNA data to create a phylogenetic chart that is more accurate and detailed. This information is more precise and gives evidence of the evolution of an organism. The analysis of molecular data can help researchers identify the number of organisms that share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationships of organisms are influenced by many factors including phenotypic plasticity, a kind of behavior that alters in response to specific environmental conditions. This can cause a trait to appear more like a species another, obscuring the phylogenetic signal. This problem can be addressed by using cladistics, which incorporates the combination of homologous and analogous traits in the tree. Additionally, phylogenetics aids predict the duration and rate at which speciation occurs. This information can aid conservation biologists in deciding which species to save from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will result in a complete and balanced ecosystem. Evolutionary Theory The main idea behind evolution is that organisms acquire various characteristics over time based on 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 an organism would evolve according to its own needs as well as the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of traits can cause changes that are passed on to the In the 1930s and 1940s, concepts from a variety of fields—including genetics, natural selection and particulate inheritance—came together to form the modern evolutionary theory synthesis that explains how evolution happens through the variation of genes within a population and how those variations change over time as a result of natural selection. This model, which includes mutations, genetic drift in gene flow, and sexual selection, can be mathematically described. Recent developments in the field of evolutionary developmental biology have shown that variation can be introduced into a species through mutation, genetic drift, and reshuffling of genes in sexual reproduction, and also through migration between populations. These processes, as well as other ones like directionally-selected selection and erosion of genes (changes in frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time and changes in phenotype (the expression of genotypes in individuals). Incorporating evolutionary thinking into all areas of biology education can improve student understanding of the concepts of phylogeny as well as evolution. In a study by Grunspan and colleagues. It was demonstrated that teaching students about the evidence for evolution increased their understanding of evolution in an undergraduate biology course. To learn more about how to teach about evolution, please 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 event; it is a process that continues today. The virus reinvents itself to avoid new drugs and bacteria evolve to resist antibiotics. Animals alter their behavior as a result of a changing environment. The changes that result are often easy to see. It wasn't until late 1980s that biologists realized that natural selection can be observed in action as well. The main reason is that different traits confer a different rate of survival as well as reproduction, and may be passed down from one generation to the next. In the past, if one particular allele, the genetic sequence that controls coloration – was present in a population of interbreeding species, it could quickly become more prevalent than all other alleles. In time, this could 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. It is easier to track evolution when an organism, like bacteria, has a rapid 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 have been collected frequently and more than 50,000 generations of E.coli have passed. Lenski's research has demonstrated that mutations can alter the rate of change and the efficiency of a population's reproduction. It also demonstrates that evolution takes time, which is hard for some to accept. Another example of microevolution is how mosquito genes for resistance to pesticides show up more often in areas where insecticides are employed. That's because the use of pesticides creates a pressure that favors individuals with resistant genotypes. The rapid pace at which evolution can take place has led to a growing recognition of its importance in a world that is shaped by human activities, including climate change, pollution, and the loss of habitats that prevent many species from adapting. Understanding evolution can assist you in making better choices about the future of our planet and its inhabitants.