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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 understand the theory of evolution and how it permeates every area of scientific inquiry. This site provides students, teachers and general readers with a wide range of educational resources on evolution. It includes the most important video clips from NOVA and WGBH's science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is seen in a variety of spiritual traditions and cultures as a symbol of unity and love. It also has many practical applications, like providing a framework for understanding the evolution of species and how they respond to changes in the environment. Early attempts to describe the world of biology were based on categorizing organisms based on their metabolic and physical characteristics. These methods, which rely on the sampling of different parts of living organisms or small fragments of their DNA significantly expanded the diversity that could be represented in a tree of life2. These trees are mostly populated by eukaryotes, and bacterial diversity is vastly underrepresented3,4. Genetic techniques have significantly expanded our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. We can construct trees using molecular methods, such as the small-subunit ribosomal gene. The Tree of Life has been dramatically expanded through genome sequencing. However, there is still much diversity to be discovered. This is particularly true of microorganisms, which can be difficult to cultivate and are usually only present in a single sample5. A recent study of all known genomes has produced a rough draft version of the Tree of Life, including numerous bacteria and archaea that have not been isolated, and whose diversity is poorly understood6. The expanded Tree of Life is particularly useful in assessing the diversity of an area, which can help to determine if specific habitats require special protection. The information is useful in a variety of ways, such as finding new drugs, fighting diseases and improving crops. 에볼루션사이트 is also valuable for conservation efforts. It can aid biologists in identifying the areas most likely to contain cryptic species with potentially significant metabolic functions that could be vulnerable to anthropogenic change. While funding to protect biodiversity are important, the best way to conserve the world's biodiversity is to empower more people in developing nations with the knowledge they need to act locally and promote conservation. Phylogeny A phylogeny (also known as an evolutionary tree) illustrates the relationship between organisms. Using molecular data, morphological similarities and differences, or ontogeny (the process of the development of an organism), scientists can build an phylogenetic tree that demonstrates the evolution of taxonomic categories. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution. A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms with similar traits and evolved from an ancestor that shared traits. These shared traits are either homologous or analogous. Homologous traits are the same in terms of their evolutionary path. Analogous traits may look like they are, but they do not have the same ancestry. Scientists group similar traits together into a grouping called a the clade. All members of a clade share a characteristic, like 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 relationship to. Scientists make use of molecular DNA or RNA 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. The use of molecular data lets researchers identify the number of species that have an ancestor common to them and estimate their evolutionary age. The phylogenetic relationship can be affected by a number of factors, including the phenotypic plasticity. This is a type behavior that alters as a result of particular environmental conditions. This can cause a trait to appear more similar to one species than another, clouding the phylogenetic signal. This issue can be cured by using cladistics. This is a method that incorporates the combination of analogous and homologous features in the tree. Additionally, phylogenetics can help determine the duration and speed at which speciation occurs. This information can aid conservation biologists in deciding which species to safeguard from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced. Evolutionary Theory The fundamental concept in evolution is that organisms change over time as a result of their interactions with their environment. Many scientists have come up with theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could evolve according to its individual requirements, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern taxonomy system that is hierarchical, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of traits can lead to changes that are passed on to the next generation. In the 1930s and 1940s, concepts from various fields, such as natural selection, genetics & particulate inheritance, merged to create a modern theorizing of evolution. This explains how evolution happens through the variation of genes in a population and how these variants alter over time due to natural selection. This model, which is known as genetic drift, mutation, gene flow and sexual selection, is a key element of modern evolutionary biology and can be mathematically described. Recent discoveries in the field of evolutionary developmental biology have revealed how variation can be introduced to a species via mutations, genetic drift and reshuffling of genes during sexual reproduction and migration between populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time) can lead to evolution which is defined by change in the genome of the species over time and also by changes in phenotype over time (the expression of the genotype in the individual). Incorporating evolutionary thinking into all areas of biology education could increase students' understanding of phylogeny and evolution. In a recent study by Grunspan et al. It was found that teaching students about the evidence for evolution boosted their acceptance of evolution during an undergraduate biology course. For more details on how to teach about evolution, see The Evolutionary Power of Biology in All Areas of Biology or Thinking Evolutionarily: a Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Scientists have traditionally studied evolution by looking in the past—analyzing fossils and comparing species. They also study living organisms. Evolution isn't a flims event, but an ongoing process. Bacteria transform and resist antibiotics, viruses re-invent themselves and elude new medications and animals change their behavior to the changing environment. The resulting changes are often visible. But it wasn't until the late 1980s that biologists understood that natural selection can be seen in action, as well. The key is that different characteristics result in different rates of survival and reproduction (differential fitness), and can be passed from one generation to the next. In the past when one particular allele – the genetic sequence that determines coloration—appeared in a population of interbreeding species, it could quickly become more common than other alleles. As time passes, that 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 observe evolution when an organism, like bacteria, has a high generation turnover. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend 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 efficiency at which a population reproduces. 에볼루션바카라 demonstrates that evolution takes time, a fact that some find difficult to accept. Microevolution can also be seen in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides have been used. Pesticides create an exclusive pressure that favors those with resistant genotypes. The speed 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 adjusting. Understanding evolution will help you make better decisions about the future of our planet and its inhabitants.