The Academy's Evolution Site<br /><br />Biological evolution is one of the most fundamental concepts in biology. The Academies have been active for a long time in helping those interested in science comprehend the concept of evolution and how it permeates all areas of scientific exploration.<br /><br />This site provides students, teachers and general readers with a variety of educational resources on evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.<br /><br />Tree of Life<br /><br />The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is used in many religions and cultures as symbolizing unity and love. It can be used in many practical ways in addition to providing a framework to understand the evolution of species and how they react to changing environmental conditions.<br /><br />The first attempts to depict the biological world were founded on categorizing organisms on their physical and metabolic characteristics. These methods, based on sampling of different parts of living organisms, or small fragments of their DNA, greatly increased the variety of organisms that could be represented in the tree of life2. These trees are mostly populated of eukaryotes, while the diversity of bacterial species is greatly underrepresented3,4.<br /><br />In avoiding the necessity of direct experimentation and observation, genetic techniques have made it possible to represent the Tree of Life in a more precise way. We can construct trees by using molecular methods such as the small subunit ribosomal gene.<br /><br />Despite the dramatic growth of the Tree of Life through genome sequencing, a lot of biodiversity remains to be discovered. This is particularly the case for microorganisms which are difficult to cultivate and which are usually only present in a single sample5. Recent analysis of all genomes resulted in an unfinished draft of the Tree of Life. This includes a wide range of bacteria, archaea and other organisms that haven't yet been isolated, or their diversity is not thoroughly understood6.<br /><br />The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, assisting to determine if certain habitats require protection. This information can be utilized in a variety of ways, including finding new drugs, fighting diseases and enhancing crops. The information is also valuable to conservation efforts. It can help biologists identify those areas that are most likely contain cryptic species with important metabolic functions that could be vulnerable to anthropogenic change. Although funds to protect biodiversity are crucial, ultimately the best way to protect 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.<br /><br />Phylogeny<br /><br />A phylogeny is also known as an evolutionary tree, reveals the connections between groups of organisms. Scientists can construct a phylogenetic chart that shows the evolutionary relationship of taxonomic groups using molecular data and morphological differences or similarities. The phylogeny of a tree plays an important role in understanding biodiversity, genetics and evolution.<br /><br />A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and evolved from a common ancestor. These shared traits could be either homologous or analogous. Homologous traits are similar in their evolutionary journey. Analogous traits may look like they are, but they do not have the same ancestry. Scientists combine similar traits into a grouping called a Clade. For instance, all the species in a clade share the characteristic of having amniotic egg and evolved from a common ancestor which had these eggs. The clades then join to form a phylogenetic branch to determine the organisms with the closest relationship.<br /><br />Scientists make use of DNA or RNA molecular information to create a phylogenetic chart that is more precise and detailed. This information is more precise and provides evidence of the evolutionary history of an organism. Researchers can utilize Molecular Data to calculate the age of evolution of living organisms and discover how many organisms share a common ancestor.<br /><br />The phylogenetic relationships of a species can be affected by a variety of factors, including phenotypicplasticity. This is a kind of behavior that changes as a result of specific environmental conditions. This can cause a trait to appear more similar in one species than another, clouding the phylogenetic signal. However, this problem can be cured by the use of methods such as cladistics which include a mix of similar and homologous traits into the tree.<br /><br />In addition, phylogenetics helps predict the duration and rate at which speciation occurs. This information can help conservation biologists decide which species they should protect from the threat of extinction. It is ultimately the preservation of phylogenetic diversity which will result in an ecosystem that is complete and balanced.<br /><br />Evolutionary Theory<br /><br />The central theme of evolution is that organisms develop different features over time due to 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 would evolve according to its own requirements, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical system of taxonomy 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<br /><br />In the 1930s and 1940s, theories from various fields, including genetics, natural selection, and particulate inheritance--came together to form the modern synthesis of evolutionary theory that explains how evolution happens through the variation of genes within a population and how those variants change over time due to natural selection. <a href="https://evolutionkr.kr/">에볼루션바카라 Evolution KR</a> , which incorporates mutations, genetic drift, gene flow and sexual selection is mathematically described mathematically.<br /><br />Recent discoveries in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species via genetic drift, mutation, and reshuffling of genes during sexual reproduction, and also through the movement of populations. These processes, along with others such as directional selection or genetic erosion (changes in the frequency of a genotype over time) can result in evolution that is defined as changes in the genome of the species over time, and also the change in phenotype as time passes (the expression of the genotype in an individual).<br /><br />Students can gain a better understanding of the concept of phylogeny by using evolutionary thinking into all aspects of biology. In a study by Grunspan and co., it was shown that teaching students about the evidence for evolution increased their understanding of evolution during a college-level course in biology. For more information on how to teach evolution, see The Evolutionary Potency in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.<br /><br />Evolution in Action<br /><br />Scientists have traditionally studied evolution through looking back in the past--analyzing fossils and comparing species. They also study living organisms. Evolution isn't a flims moment; it is a process that continues today. Bacteria evolve and resist antibiotics, viruses re-invent themselves and are able to evade new medications and animals alter their behavior to the changing environment. The changes that result are often visible.<br /><br /><br /><br />However, it wasn't until late 1980s that biologists realized that natural selection can be seen in action, as well. The key to this is that different traits result in a different rate of survival as well as reproduction, and may be passed down from one generation to another.<br /><br />In the past, if one allele - the genetic sequence that determines color - was found in a group of organisms that interbred, it might become more common than any other allele. In time, this could mean the number of black moths in the population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.<br /><br />The ability to observe evolutionary change is easier when a particular species has a rapid generation turnover like bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that are descended from one strain. Samples from each population have been taken regularly and more than 500.000 generations of E.coli have passed.<br /><br />Lenski's research has revealed that mutations can alter the rate at which change occurs and the rate of a population's reproduction. It also demonstrates that evolution takes time, which is hard for some to accept.<br /><br />Microevolution can be observed in the fact that mosquito genes for pesticide resistance are more common in populations where insecticides are used. This is because the use of pesticides creates a selective pressure that favors those with resistant genotypes.<br /><br />The rapidity of evolution has led to an increasing awareness of its significance particularly in a world that is largely shaped by human activity. This includes the effects of climate change, pollution and habitat loss that prevents many species from adapting. Understanding the evolution process will help you make better decisions regarding the future of the planet and its inhabitants.<br /><br />