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The Academy's Evolution Site Biological evolution is a central concept in biology. The Academies have been for a long time involved in helping those interested in science comprehend the theory of evolution and how it permeates every area of scientific inquiry. This site provides teachers, students and general readers with a wide range of learning resources on evolution. It contains important video clips from NOVA and the WGBH-produced science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It appears in many spiritual traditions and cultures as an emblem of unity and love. It also has practical applications, such as providing a framework to understand the evolution of species and how they react to changing environmental conditions. Early attempts to represent the world of biology were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which are based on the collection of various parts of organisms or short DNA fragments have greatly increased the diversity of a tree of Life2. These trees are largely composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4. Genetic techniques have greatly expanded our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. Particularly, molecular methods allow us to build trees by using sequenced markers, such as the small subunit of ribosomal RNA gene. Despite the massive growth of the Tree of Life through genome sequencing, much biodiversity still is waiting to be discovered. This is especially true for microorganisms that are difficult to cultivate and which are usually only found in one sample5. Recent analysis of all genomes produced an initial draft of a Tree of Life. This includes a variety of archaea, bacteria, and other organisms that haven't yet been isolated, or the diversity of which is not well understood6. This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, helping to determine if specific habitats require special protection. This information can be used in a variety of ways, from identifying the most effective treatments to fight disease to enhancing the quality of the quality of crops. The information is also useful for conservation efforts. It can help biologists identify those areas that are most likely contain cryptic species that could have significant metabolic functions that could be at risk from anthropogenic change. While funds to protect biodiversity are crucial, ultimately the best way to protect the world's biodiversity is for more people living in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within. Phylogeny A phylogeny (also known as an evolutionary tree) illustrates the relationship between different organisms. Scientists can construct a phylogenetic chart that shows the evolutionary relationship of taxonomic categories using molecular information and morphological differences or similarities. The concept of phylogeny is fundamental to understanding evolution, biodiversity and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that have evolved from common ancestors. These shared traits can be either homologous or analogous. Homologous traits are the same in terms of their evolutionary journey. Analogous traits could appear similar, but they do not have the same ancestry. Scientists group similar traits together into a grouping called a clade. Every organism in a group share a trait, such as amniotic egg production. They all derived from an ancestor that had these eggs. The clades are then linked to form a phylogenetic branch to identify organisms that have the closest relationship to. Scientists use DNA or RNA molecular data to construct a phylogenetic graph which is more precise and precise. This data is more precise than morphological information and provides evidence of the evolutionary history of an individual or group. Researchers can use Molecular Data to determine the age of evolution of living organisms and discover the number of organisms that share an ancestor common to all. The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic plasticity a type of behavior that changes in response to unique environmental conditions. This can cause a particular trait to appear more similar in one species than another, obscuring the phylogenetic signal. This problem can be addressed by using cladistics. This is a method that incorporates a combination of analogous and homologous features in the tree. Additionally, phylogenetics can aid in predicting the length and speed of speciation. This information can aid conservation biologists in making choices about which species to save from extinction. In the end, it's the conservation of phylogenetic variety that will lead to an ecosystem that is balanced and complete. Evolutionary Theory The fundamental concept of evolution is that organisms acquire different features over time due to their interactions with their environment. Many theories of evolution have been developed by a variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly according to its requirements, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits cause changes that can be passed on to the offspring. In the 1930s and 1940s, concepts from a variety of fields — including genetics, natural selection, and particulate inheritance — came together to create the modern synthesis of evolutionary theory that explains how evolution occurs through the variations of genes within a population, and how those variations change over time due to natural selection. This model, which includes mutations, genetic drift as well as gene flow and sexual selection, can be mathematically described mathematically. Recent developments in the field of evolutionary developmental biology have demonstrated that variation can be introduced into a species via mutation, genetic drift, and reshuffling of genes during sexual reproduction, as well as through the movement of populations. These processes, as well as others, such as directionally-selected selection and erosion of genes (changes to the frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes within individuals). Incorporating evolutionary thinking into all aspects of biology education can increase student understanding of the concepts of phylogeny and evolution. In a recent study conducted by Grunspan et al. It was demonstrated that teaching students about the evidence for evolution increased their acceptance of evolution during the course of a college biology. To learn more about how to teach about evolution, look up The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Scientists have traditionally studied evolution through looking back in the past—analyzing fossils and comparing species. They also observe living organisms. Evolution is not a distant event, but an ongoing process that continues to be observed today. Viruses evolve to stay away from new drugs and bacteria evolve to resist antibiotics. Animals adapt their behavior as a result of the changing environment. The changes that result are often easy to see. However, it wasn't until late 1980s that biologists understood that natural selection could be observed in action as well. 에볼루션 슬롯게임 is that different traits can confer the ability to survive at different rates and reproduction, and they can be passed down from one generation to another. In the past when one particular allele – the genetic sequence that determines coloration—appeared in a population of interbreeding organisms, it might quickly become more prevalent than the other alleles. In time, this could mean that the number of black moths within the population could increase. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. The ability to observe evolutionary change is easier when a species has a rapid turnover of its generation like bacteria. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. Coli that descended from a single strain; samples of each are taken on a regular basis and over fifty thousand generations have been observed. Lenski's research has demonstrated 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 hard for some to accept. Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more prevalent in areas where insecticides have been used. Pesticides create an exclusive pressure that favors those with resistant genotypes. The rapidity of evolution has led to a growing appreciation of its importance, especially in a world which is largely shaped by human activities. This includes pollution, climate change, and habitat loss, which prevents many species from adapting. Understanding the evolution process will aid you in making better decisions about the future of the planet and its inhabitants.