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The Academy's Evolution Site Biology is one of the most important concepts in biology. The Academies have long been involved in helping people who are interested in science comprehend the concept of evolution and how it permeates every area of scientific inquiry. This site provides teachers, students and general readers with a variety of educational resources on evolution. It includes key video clip from NOVA and WGBH produced science programs on DVD. Tree of Life The Tree of Life is an ancient symbol of the interconnectedness of all life. It is seen in a variety of religions and cultures as symbolizing unity and love. It has numerous practical applications as well, such as providing a framework to understand the evolution of species and how they react to changing environmental conditions. The first attempts at depicting the biological world focused on separating organisms into distinct categories that were identified by their physical and metabolic characteristics1. These methods, based on the sampling of various parts of living organisms, or sequences of short fragments of their DNA, greatly increased the variety of organisms that could be included in a tree of life2. The trees are mostly composed by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4. By avoiding the necessity for direct observation and experimentation, genetic techniques have enabled us to depict the Tree of Life in a more precise manner. We can construct trees using molecular methods, such as the small-subunit ribosomal gene. Despite the dramatic growth of the Tree of Life through genome sequencing, a large amount of biodiversity awaits discovery. This is particularly true for microorganisms that are difficult to cultivate and are typically found in one sample5. Recent analysis of all genomes produced a rough draft of the Tree of Life. This includes a variety of archaea, bacteria, and other organisms that have not yet been isolated, or whose diversity has not been fully understood6. The expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if particular habitats require special protection. This information can be utilized in a range of ways, from identifying the most effective remedies to fight diseases to enhancing crops. It is also valuable in conservation efforts. It helps biologists discover areas most likely to have species that are cryptic, which could perform important metabolic functions and be vulnerable to human-induced change. While funds to protect biodiversity are essential however, the most effective method to protect the world's biodiversity is for more people living in developing countries to be equipped with the knowledge to act locally in order to promote conservation from within. Phylogeny A phylogeny (also called an evolutionary tree) illustrates the relationship between different organisms. By using molecular information, morphological similarities and differences or ontogeny (the process of the development of an organism), scientists can build a phylogenetic tree that illustrates the evolutionary relationships between taxonomic groups. 에볼루션사이트 plays a crucial role in understanding genetics, biodiversity and evolution. A basic phylogenetic tree (see Figure PageIndex 10 Identifies the relationships between organisms that have similar characteristics and have evolved from an ancestor that shared traits. These shared traits can be analogous, or homologous. Homologous traits are similar in their underlying evolutionary path while analogous traits appear similar, but do not share the same ancestors. Scientists group similar traits into a grouping known as a the clade. For instance, all the organisms in a clade share the characteristic of having amniotic eggs. They evolved from a common ancestor who had these eggs. The clades then join to form a phylogenetic branch to identify organisms that have the closest connection to each other. To create a more thorough and precise phylogenetic tree scientists use molecular data from DNA or RNA to establish the relationships between organisms. This information is more precise and gives evidence of the evolutionary history of an organism. The use of molecular data lets researchers identify the number of species who share a common ancestor and to estimate their evolutionary age. The phylogenetic relationships of a species can be affected by a variety of factors, including phenotypicplasticity. This is a kind of behaviour that can change as a result of unique environmental conditions. This can cause a trait to appear more similar to one species than another which can obscure the phylogenetic signal. This issue can be cured by using cladistics. This is a method that incorporates an amalgamation of homologous and analogous features in the tree. Additionally, phylogenetics can aid in predicting the duration and rate of speciation. This information can help conservation biologists decide which species to protect from the threat of extinction. In 에볼루션사이트 , it's 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 develop different features over time due to their interactions with their environment. Many theories of evolution have been proposed by a wide variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly in accordance with its requirements and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who developed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits can cause changes that could be passed on to offspring. In the 1930s and 1940s, ideas from a variety of fields — including genetics, natural selection and particulate inheritance – came together to form the modern evolutionary theory that explains how evolution occurs through the variation of genes within a population and how these variants change in time as a result of natural selection. This model, which incorporates genetic drift, mutations as well as gene flow and sexual selection, can be mathematically described mathematically. Recent developments in the field of evolutionary developmental biology have shown the ways in which variation can be introduced to a species via genetic drift, mutations or reshuffling of genes in sexual reproduction and migration between populations. These processes, along with others, such as directional selection and gene erosion (changes to the frequency of genotypes over time) can lead to evolution. Evolution is defined by changes in the genome over time, as well as changes in phenotype (the expression of genotypes in individuals). Students can better understand the concept of phylogeny through incorporating evolutionary thinking into all aspects of biology. A recent study by Grunspan and colleagues, for example demonstrated that teaching about the evidence supporting evolution increased students' acceptance of evolution in a college-level biology course. To find out more about how to teach about evolution, please look up The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education. Evolution in Action Scientists have studied evolution by looking in the past, studying fossils, and comparing species. They also study living organisms. But evolution isn't a thing that happened in the past; it's an ongoing process happening today. Bacteria mutate and resist antibiotics, viruses reinvent themselves and elude new medications and animals change their behavior to a changing planet. The results are usually easy to see. However, it wasn't until late 1980s that biologists realized that natural selection can be seen in action, as well. The key is that various traits confer 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 group of interbreeding organisms, it could rapidly become more common than the other alleles. In time, this could mean that the number of moths sporting black pigmentation in a group could increase. 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 rapid generation turnover. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples of each population are taken every day and more than 50,000 generations have now been observed. Lenski's research has revealed that mutations can alter the rate of change and the rate of a population's reproduction. It also demonstrates that evolution takes time, something that 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. That's because the use of pesticides creates a selective pressure that favors people who have 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 the effects of climate change, pollution and habitat loss that hinders many species from adapting. Understanding evolution can help us make better decisions regarding the future of our planet as well as the lives of its inhabitants.