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The Academy's Evolution Site The concept of biological evolution is among the most central concepts in biology. The Academies are involved in helping those who are interested in science comprehend the evolution theory and how it can be applied in all areas of scientific research. This site provides a wide range of resources for students, teachers and general readers of 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 symbolizes the interconnectedness of life. It is an emblem of love and unity across many cultures. It can be used in many practical ways as well, such as providing a framework for understanding the evolution 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, based on sampling of different parts of living organisms or on short fragments of their DNA significantly increased the variety that could be represented in the 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 experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a more precise manner. In particular, molecular methods enable us to create trees using sequenced markers like the small subunit ribosomal gene. The Tree of Life has been greatly expanded thanks to genome sequencing. However, there is still much biodiversity to be discovered. This is particularly true of microorganisms, which are difficult to cultivate and are often only present in a single specimen5. A recent analysis of all genomes produced an unfinished draft of the Tree of Life. This includes a large number of archaea, bacteria, and other organisms that have not yet been isolated or whose diversity has not been well understood6. The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, which can help to determine if certain habitats require protection. The information can be used in a variety of ways, from identifying the most effective medicines to combating disease to enhancing crop yields. The information is also incredibly useful in conservation efforts. It helps biologists discover areas most likely to have species that are cryptic, which could perform important metabolic functions and are susceptible to the effects of human activity. Although funding to protect biodiversity are essential, ultimately the best way to ensure the preservation of biodiversity around the world is for more people in developing countries to be equipped with the knowledge to act locally to promote conservation from within. Phylogeny A phylogeny (also called an evolutionary tree) illustrates the relationship between species. Scientists can build a phylogenetic chart that shows the evolutionary relationships between taxonomic groups based on molecular data and morphological differences or similarities. Phylogeny is crucial in understanding biodiversity, evolution and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that have evolved from common ancestors. These shared traits are either analogous or homologous. Homologous traits are the same in their evolutionary paths. Analogous traits could appear like they are, but they do not have the same ancestry. Scientists group similar traits into a grouping called a clade. For example, all of the species in a clade share the trait of having amniotic eggs. They evolved from a common ancestor which had eggs. The clades then join to form a phylogenetic branch to identify organisms that have the closest relationship to. For a more detailed and accurate phylogenetic tree scientists make use of molecular data from DNA or RNA to determine the relationships among organisms. This information is more precise and gives evidence of the evolution history of an organism. Researchers can utilize Molecular Data to determine the age of evolution of organisms and determine how many organisms have a common ancestor. The phylogenetic relationship can be affected by a variety of factors such as the phenomenon of phenotypicplasticity. This is a kind of behavior that changes as a result of particular environmental conditions. Suggested Resource site can make a trait appear more resembling to one species than to another which can obscure the phylogenetic signal. However, this problem can be cured by the use of methods such as cladistics that include a mix of similar and homologous traits into the tree. Furthermore, phylogenetics may aid in predicting the length and speed of speciation. This information can assist conservation biologists in making choices about which species to safeguard from disappearance. It is ultimately the preservation of phylogenetic diversity which will result in an ecosystem that is complete and balanced. Evolutionary Theory The fundamental concept in evolution is that organisms alter over time because of their interactions with their environment. Many scientists have proposed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that a living thing would evolve according to its individual requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern taxonomy system that is hierarchical and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of certain traits can result in changes that are passed on to the In the 1930s & 1940s, ideas from different areas, including natural selection, genetics & particulate inheritance, merged to form a modern theorizing of evolution. This explains how evolution happens through the variation of genes in the population and how these variants change with time due to natural selection. This model, which is known as genetic drift mutation, gene flow and sexual selection, is the foundation of modern evolutionary biology and can be mathematically described. Recent developments in the field of evolutionary developmental biology have revealed that variation can be introduced into a species via mutation, genetic drift and reshuffling of genes during sexual reproduction, and also by migration between populations. These processes, as well as other ones like directional selection and genetic erosion (changes in the frequency of the genotype over time) can lead to evolution, which is defined by changes in the genome of the species over time, and the change in phenotype as time passes (the expression of that genotype in the individual). Students can better understand phylogeny by incorporating evolutionary thinking into all aspects of biology. In a recent study by Grunspan and co. It was found that teaching students about the evidence for evolution boosted their understanding of evolution during the course of a college biology. To learn 에볼루션 슬롯 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 studied evolution by looking in the past—analyzing fossils and comparing species. They also observe living organisms. Evolution is not a distant event, but a process that continues today. Viruses reinvent themselves to avoid new drugs and bacteria evolve to resist antibiotics. Animals alter their behavior in the wake of a changing environment. The resulting changes are often evident. But it wasn't until the late-1980s that biologists realized that natural selection could be seen in action, as well. The key is the fact that different traits result in the ability to survive at different rates as well as reproduction, and may be passed down from generation to generation. In the past, if one allele – the genetic sequence that determines colour was present in a population of organisms that interbred, it could become more prevalent than any other allele. Over time, this would 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. Monitoring evolutionary changes in action is easier when a particular species has a rapid generation turnover like bacteria. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples from each population are taken regularly, and over fifty thousand generations have been observed. Lenski's research has revealed that mutations can alter the rate of change and the efficiency at which a population reproduces. It also demonstrates that evolution takes time, a fact that is hard for some to accept. Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more common in populations that have used insecticides. That's because the use of pesticides creates a selective pressure that favors people who have resistant genotypes. The speed at which evolution takes place has led to a growing appreciation of its importance in a world shaped by human activity, including climate change, pollution and the loss of habitats that hinder the species from adapting. Understanding evolution will help you make better decisions about the future of the planet and its inhabitants.