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The Academy's Evolution Site Biological evolution is a central concept in biology. The Academies are committed to helping those who are interested in science to comprehend the evolution theory and how it is incorporated in all areas of scientific research. This site provides teachers, students and general readers with a wide range of learning resources on evolution. It contains key 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 is used in many religions and cultures as symbolizing unity and love. It also has important practical uses, like providing a framework for understanding the evolution of species and how they respond to changes in environmental conditions. The first attempts at depicting the biological world focused on the classification of organisms into distinct categories that had been identified by their physical and metabolic characteristics1. These methods are based on the sampling of different parts of organisms or DNA fragments have significantly increased the diversity of a tree of Life2. However, these trees are largely made up of eukaryotes. Bacterial diversity is still largely unrepresented3,4. Genetic techniques have significantly expanded our ability to represent the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular methods enable us to create trees by using sequenced markers such as the small subunit ribosomal gene. Despite the rapid expansion of the Tree of Life through genome sequencing, a large amount of biodiversity awaits discovery. This is especially true of microorganisms, which are difficult to cultivate and are usually only found in a single sample5. Recent analysis of all genomes produced an initial 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 thoroughly understood6. The expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if certain habitats require special protection. The information can be used in a range of ways, from identifying new medicines to combating disease to enhancing the quality of crop yields. This information is also valuable to conservation efforts. It can aid biologists in identifying areas that are most likely to be home to cryptic species, which could perform important metabolic functions, and could be susceptible to human-induced change. While funds to safeguard biodiversity are vital, ultimately the best way to protect the world's biodiversity is for more people living in developing countries to be equipped with the knowledge to act locally to promote conservation from within. Phylogeny A phylogeny, also known as an evolutionary tree, reveals the connections between various groups of organisms. Scientists can create a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic categories using molecular information and morphological differences or similarities. Phylogeny is crucial in understanding evolution, biodiversity and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that evolved from common ancestors. These shared traits could be either homologous or analogous. Homologous characteristics are identical in their evolutionary path. Analogous traits may look like they are, but they do not have the same ancestry. Scientists arrange similar traits into a grouping known as a the clade. All members of a clade share a characteristic, like amniotic egg production. They all derived from an ancestor that had these eggs. A phylogenetic tree can be built by connecting the clades to identify the organisms which are the closest to one another. Scientists use DNA or RNA molecular data to create a phylogenetic chart that is more precise and precise. This information is more precise than morphological information and gives evidence of the evolutionary background of an organism or group. Researchers can utilize Molecular Data to estimate the age of evolution of organisms and identify how many organisms have an ancestor common to all. The phylogenetic relationships between organisms can be affected by a variety of factors including phenotypic plasticity, a kind of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more like a species another, obscuring the phylogenetic signal. This issue can be cured by using cladistics, which is a a combination of homologous and analogous features in the tree. Furthermore, phylogenetics may help predict the duration and rate of speciation. This information can aid conservation biologists in making decisions about which species to save from extinction. In the end, it is the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced. Evolutionary Theory The main idea behind 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 a living thing would evolve according to its own needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical system of taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or non-use of certain traits can result in changes that can be passed on to future generations. In the 1930s and 1940s, concepts from various fields, including natural selection, genetics & particulate inheritance, came together to form a contemporary synthesis of evolution theory. This defines how evolution is triggered by the variations in genes within the population and how these variants change with time due to natural selection. This model, which encompasses genetic drift, mutations as well as gene flow and sexual selection is mathematically described. Recent developments in the field of evolutionary developmental biology have revealed that variation can be introduced into a species through mutation, genetic drift and reshuffling genes during sexual reproduction, as well as through the movement of populations. These processes, in conjunction with others, such as the directional selection process and the erosion of genes (changes in the frequency of genotypes over time) can lead to evolution. Evolution is defined as changes in the genome over time and changes in phenotype (the expression of genotypes within individuals). Incorporating evolutionary thinking into all aspects of biology education can 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 boosted their understanding of evolution during the course of a college biology. For more information on how to teach evolution read The Evolutionary Potency 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 is not a distant moment; it is a process that continues today. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals adapt their behavior as a result of the changing environment. The results are usually visible. It wasn't until late 1980s that biologists understood that natural selection could be seen in action, as well. The key is that different traits have different rates of survival and reproduction (differential fitness) and can be transferred from one generation to the next. In the past, if an allele – the genetic sequence that determines colour appeared in a population of organisms that interbred, it could be more common than other allele. In time, this could mean that the number of moths that have black pigmentation in a population may increase. 에볼루션 무료 바카라 is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. It is easier to observe evolutionary change when the species, like bacteria, has a rapid generation turnover. Since 1988, Richard Lenski, a biologist, has been tracking twelve populations of E.coli that descend from a single strain. The samples of each population have been collected frequently and more than 50,000 generations of E.coli have been observed to have passed. Lenski's research has shown that a mutation can dramatically alter the efficiency with which a population reproduces—and so, the rate at which it changes. It also shows that evolution takes time, something that is difficult for some to accept. Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas that have used insecticides. This is due to the fact that the use of pesticides causes a selective pressure that favors those with resistant genotypes. The rapidity of evolution has led to a growing recognition of its importance especially in a planet shaped largely by human activity. This includes the effects of climate change, pollution and habitat loss, which prevents many species from adapting. Understanding the evolution process can assist you in making better choices about the future of our planet and its inhabitants.