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10 Misconceptions That Your Boss May Have About Evolution Site The Academy's Evolution Site The concept of biological evolution is a fundamental concept in biology. The Academies are committed to helping those interested in science learn about the theory of evolution and how it can be applied in all areas of scientific research. This site provides a wide range of tools for teachers, students, and general readers on 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 used in many religions and cultures as symbolizing unity and love. It also has many practical applications, like providing a framework to understand the evolution of species and how they react to changes in environmental conditions. The first attempts to depict the biological world were founded on categorizing organisms on their physical and metabolic characteristics. These methods, which relied on the sampling of different parts of living organisms or short fragments of their DNA, significantly expanded the diversity that could be included in the tree of life2. However the trees are mostly comprised of eukaryotes, and bacterial diversity remains vastly underrepresented3,4. In avoiding the necessity of direct experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a more precise way. In particular, molecular methods allow us to build trees using sequenced markers such as the small subunit ribosomal RNA gene. Despite the massive growth of the Tree of Life through genome sequencing, much biodiversity still awaits discovery. This is especially the case for microorganisms which are difficult to cultivate and are typically found in one sample5. A recent study of all genomes that are known has produced a rough draft of the Tree of Life, including many bacteria and archaea that are not isolated and whose diversity is poorly understood6. This expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if certain habitats need special protection. The information can be used in a range of ways, from identifying the most effective treatments to fight disease to enhancing crop yields. This information is also extremely beneficial for conservation efforts. It helps biologists discover areas that are most likely to have species that are cryptic, which could perform important metabolic functions and be vulnerable to human-induced change. Although funds to safeguard biodiversity are vital, ultimately the best way to preserve the world's biodiversity is for more people living in developing countries to be empowered with the knowledge to act locally to promote conservation from within. Phylogeny A phylogeny, also known as an evolutionary tree, illustrates the relationships between groups of organisms. Scientists can construct a phylogenetic chart that shows the evolutionary relationships between taxonomic groups using molecular data and morphological differences or similarities. The role of phylogeny is crucial in understanding biodiversity, genetics and evolution. A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms with similar traits that have evolved from common ancestral. These shared traits are either analogous or homologous. Homologous traits share their evolutionary origins while analogous traits appear like they do, but don't have the same ancestors. Scientists organize similar traits into a grouping called a the clade. For instance, all of the species in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor who had these eggs. A phylogenetic tree can be constructed by connecting clades to determine the organisms that are most closely related to one another. Scientists utilize DNA or RNA molecular data to construct a phylogenetic graph that is more precise and detailed. This information is more precise and provides evidence of the evolution of an organism. The analysis of molecular data can help researchers determine 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 flexibility, a type of behavior that alters in response to unique environmental conditions. This can cause a trait to appear more similar to a species than to the other, obscuring the phylogenetic signals. However, this issue can be solved through the use of techniques such as cladistics that combine homologous and analogous features into the tree. In addition, phylogenetics can aid in predicting the length and speed of speciation. This information can aid conservation biologists in making decisions about which species to protect from the threat of extinction. In the end, it's the preservation of phylogenetic diversity which will result in an ecologically balanced and complete ecosystem. 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 developed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could develop according to its own needs as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy and Jean-Baptiste Lamarck (1844-1829), who believed that the use or non-use of certain traits can result in changes that are passed on to the In the 1930s and 1940s, ideas from different fields, such as genetics, natural selection and particulate inheritance, merged to form a contemporary evolutionary theory. This explains how evolution happens through the variations in genes within a population and how these variations alter over time due to natural selection. This model, which incorporates mutations, genetic drift, gene flow and sexual selection can be mathematically described. Recent developments in the field of evolutionary developmental biology have demonstrated that genetic variation can be introduced into a species by mutation, genetic drift and reshuffling of genes in sexual reproduction, as well as through migration between populations. These processes, along with other ones like directional selection and gene erosion (changes to the frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time as well as changes in the phenotype (the expression of genotypes in an individual). Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all aspects of biology. In a study by Grunspan and co. It was demonstrated that teaching students about the evidence for evolution increased their understanding of evolution in the course of a college biology. To find out more about how to teach about evolution, look up The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily A Framework for Infusing the Concept of Evolution into Life Sciences Education. Evolution in Action Traditionally scientists have studied evolution through studying fossils, comparing species, and observing living organisms. However, evolution isn't something that occurred in the past. It's an ongoing process, taking place today. Viruses reinvent themselves to avoid new drugs and bacteria evolve to resist antibiotics. Animals alter their behavior because of the changing environment. The changes that result are often evident. It wasn't until late-1980s that biologists realized that natural selection could be seen in action, as well. The key is that various characteristics result in different rates of survival and reproduction (differential fitness) and are passed down from one generation to the next. In the past, when one particular allele, the genetic sequence that defines color in a population of interbreeding species, it could rapidly become more common than all other alleles. Over time, that would mean the number of black moths within a population could increase. 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 tracked twelve populations of E.coli that descend from one strain. The samples of each population have been collected regularly and more than 50,000 generations of E.coli have passed. Lenski's research has shown that a mutation can dramatically alter the speed at the rate at which a population reproduces, and consequently, the rate at which it alters. It also proves that evolution takes time--a fact that some people 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 are used. This is due to the fact that the use of pesticides causes a selective pressure that favors those who have resistant genotypes. 에볼루션 코리아 of evolution has led to an increasing awareness of its significance especially in a planet shaped largely by human activity. This includes pollution, climate change, and habitat loss that hinders many species from adapting. Understanding the evolution process can help us make smarter choices about the future of our planet as well as the lives of its inhabitants.
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