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The Academy's Evolution Site Biology is a key concept in biology. The Academies have been for a long time involved in helping those interested in science understand the theory of evolution and how it affects all areas of scientific research. This site provides students, teachers and general readers with a variety of learning 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 that represents the interconnectedness of life. It is seen in a variety of cultures and spiritual beliefs as symbolizing unity and love. It has numerous practical applications as well, including providing a framework for understanding the history of species, and how they react to changing environmental conditions. Early attempts to represent the biological world were founded on categorizing organisms on their metabolic and physical characteristics. These methods rely on the sampling of different parts of organisms, or fragments of DNA, have significantly increased the diversity of a tree of Life2. These trees are mostly populated of eukaryotes, while bacterial diversity is vastly underrepresented3,4. By avoiding the need for direct experimentation and observation, genetic techniques have made it possible to depict the Tree of Life in a much more accurate way. Particularly, molecular techniques allow us to build trees using sequenced markers like the small subunit ribosomal gene. Despite the rapid growth of the Tree of Life through genome sequencing, much biodiversity still is waiting to be discovered. This is particularly true of microorganisms, which can be difficult to cultivate and are usually only present in a single sample5. Recent analysis of all genomes resulted in an unfinished draft of a Tree of Life. This includes a large number of bacteria, archaea 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 evaluate the biodiversity of a particular area and determine if certain habitats need special protection. The information can be used in a variety of ways, from identifying new treatments to fight disease to enhancing crops. This information is also beneficial in conservation efforts. It can help biologists identify those areas that are most likely contain cryptic species that could have important metabolic functions that could be at risk of anthropogenic changes. Although funding to safeguard biodiversity are vital but the most effective way to protect the world's biodiversity is for more people living in developing countries to be empowered 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 organisms. Scientists can create an phylogenetic chart which shows the evolution of taxonomic groups based on molecular data and morphological differences or similarities. Phylogeny plays a crucial role in understanding genetics, biodiversity and evolution. A basic phylogenetic Tree (see Figure PageIndex 10 Determines the relationship between organisms that have similar characteristics and have evolved from a common ancestor. These shared traits may be analogous, or homologous. Homologous traits are identical in their evolutionary origins, while analogous traits look similar but do not have the identical origins. Scientists arrange similar traits into a grouping called a clade. Every organism in a group have a common characteristic, like amniotic egg production. They all evolved from an ancestor who had these eggs. A phylogenetic tree can be built by connecting the clades to identify the species who are the closest to each other. Scientists make use of DNA or RNA molecular information to create a phylogenetic chart that is more accurate and precise. This information is more precise and gives evidence of the evolution history of an organism. Molecular data allows researchers to identify the number of species that share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationship can be affected by a number of factors such as the phenomenon of phenotypicplasticity. This is a kind of behavior that changes due to unique environmental conditions. This can cause a trait to appear more like a species another, obscuring the phylogenetic signal. However, this issue can be reduced by the use of techniques like cladistics, which incorporate a combination of similar and homologous traits into the tree. In addition, phylogenetics helps predict the duration and rate at which speciation occurs. This information can aid conservation biologists to decide the species they should safeguard from the threat of extinction. In the end, it is the conservation of phylogenetic variety that will lead to an ecosystem that is complete and balanced. Evolutionary Theory The main idea behind evolution is that organisms acquire various characteristics over time as a result of their interactions with their surroundings. Many scientists have come up with theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that a living thing would evolve according to its own needs as well as the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical system of taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the use or non-use of traits can cause changes that are passed on to the In the 1930s and 1940s, theories from various fields, including natural selection, genetics & particulate inheritance, were brought together to form a modern synthesis of evolution theory. This describes how evolution is triggered by the variation in genes within a population and how these variants change with time due to natural selection. This model, which includes genetic drift, mutations, gene flow and sexual selection, can be mathematically described mathematically. Recent discoveries in the field of evolutionary developmental biology have shown that genetic variation can be introduced into a species via mutation, genetic drift, and reshuffling of genes during sexual reproduction, as well as through migration between populations. These processes, along with other ones like directionally-selected selection and erosion of genes (changes in the frequency of genotypes over time) can result in evolution. Evolution is defined as changes in the genome over time, as well as changes in phenotype (the expression of genotypes in individuals). Incorporating evolutionary thinking into all aspects of biology education could increase students' understanding of phylogeny as well as evolution. A recent study conducted by Grunspan and colleagues, for example revealed that teaching students about the evidence supporting evolution increased students' acceptance of evolution in a college-level biology class. For more details on how to teach about evolution, see The Evolutionary Power of Biology in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating 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 a process that continues today. Bacteria mutate and resist antibiotics, viruses evolve and elude new medications and animals alter their behavior to a changing planet. The changes that occur are often apparent. But it wasn't until the 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 are transferred from one generation to the next. In the past, if a certain allele – the genetic sequence that determines color – appeared in a population of organisms that interbred, it could become more prevalent than any other allele. As time passes, that could mean that 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 observe evolution when an organism, like bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that are descended from a single strain. Samples of each population have been collected regularly and more than 500.000 generations of E.coli have passed. Lenski's research has demonstrated that mutations can alter the rate of change and the efficiency of a population's reproduction. 에볼루션 슬롯게임 proves that evolution is slow-moving, a fact that many find difficult to accept. Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides are used. This is because the use of pesticides creates a selective pressure that favors individuals with resistant genotypes. The rapid pace at which evolution takes place has led to an increasing awareness of its significance in a world shaped by human activity, including climate changes, pollution and the loss of habitats that prevent many species from adapting. Understanding evolution can help us make smarter decisions regarding the future of our planet, and the lives of its inhabitants.