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The Academy's Evolution Site Biology is one of the most central concepts in biology. The Academies have long been involved in helping those interested in science comprehend the concept of evolution and how it permeates all areas of scientific research. This site provides teachers, students and general readers with a variety of learning resources on evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is a symbol of love and harmony in a variety of cultures. It has numerous practical applications as well, such as providing a framework to understand the history of species, and how they respond to changes in environmental conditions. Early attempts to describe the world of biology were built on categorizing organisms based on their physical and metabolic characteristics. These methods, based on the sampling of different parts of living organisms, or sequences of small fragments of their DNA significantly increased the variety that could be included in the tree of life2. These trees are largely composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4. Genetic techniques have greatly expanded our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. Trees can be constructed using molecular techniques, such as the small-subunit ribosomal gene. The Tree of Life has been greatly expanded thanks to genome sequencing. However, there is still much biodiversity to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are typically only present in a single sample5. Recent analysis of all genomes produced a rough draft of the Tree of Life. This includes a variety of bacteria, archaea and other organisms that have not yet been isolated, or their diversity is not fully understood6. This expanded Tree of Life is particularly useful in assessing the diversity of an area, which can help to determine whether specific habitats require special protection. This information can be utilized in a variety of ways, from identifying new remedies to fight diseases to enhancing the quality of crops. This information is also extremely useful in conservation efforts. It helps biologists determine the areas that are most likely to contain cryptic species with important metabolic functions that could be at risk of anthropogenic changes. While funding to protect biodiversity are important, the most effective method to preserve the world's biodiversity is to empower the people of developing nations with the information they require to act locally and support conservation. Phylogeny A phylogeny, also called an evolutionary tree, shows the connections between groups of organisms. By using molecular information, morphological similarities and differences, or ontogeny (the course of development of an organism), scientists can build a phylogenetic tree which illustrates the evolutionary relationship between taxonomic categories. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution. A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that have evolved from common ancestral. These shared traits could be analogous or homologous. Homologous traits are the same in their evolutionary journey. Analogous traits may look similar, but they do not have the same ancestry. Scientists organize similar traits into a grouping referred to as a Clade. All members of a clade have a common characteristic, like amniotic egg production. They all came from an ancestor who had these eggs. The clades are then connected to create a phylogenetic tree to determine which organisms have the closest relationship. For 에볼루션 바카라 무료 detailed and precise phylogenetic tree scientists make use of molecular data from DNA or RNA to determine the relationships among organisms. This information is more precise than the morphological data and provides evidence of the evolutionary history of an individual or group. Researchers can use Molecular Data to determine the evolutionary age of organisms and identify how many species share an ancestor common to all. Phylogenetic relationships can be affected by a number of factors that include the phenomenon of phenotypicplasticity. This is a type of behavior that alters in response to specific environmental conditions. This can cause a trait to appear more like a species other species, which can obscure the phylogenetic signal. However, this problem can be reduced by the use of methods such as cladistics that incorporate a combination of homologous and analogous features into the tree. Additionally, phylogenetics can help determine the duration and speed 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 that will create an ecosystem that is complete and balanced. Evolutionary Theory The fundamental concept in evolution is that organisms change 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 could evolve according to its own needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of traits can cause changes that are passed on to the In the 1930s & 1940s, theories from various fields, such as genetics, natural selection, and particulate inheritance, merged to create a modern synthesis of evolution theory. This defines how evolution is triggered by the variations in genes within the population, and how these variants change over time as a result of natural selection. This model, known as genetic drift mutation, gene flow, and sexual selection, is the foundation of the current evolutionary biology and can be mathematically described. Recent discoveries in the field of evolutionary developmental biology have revealed that variations can be introduced into a species through genetic drift, mutation, and reshuffling genes during sexual reproduction, as well as by migration between populations. These processes, in conjunction with other ones like the directional selection process and the erosion of genes (changes to the frequency of genotypes over time), can lead towards evolution. 에볼루션 코리아 is defined as changes in the genome over time, as well as changes in the phenotype (the expression of genotypes within individuals). Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking throughout all aspects of biology. In a recent study by Grunspan et al., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during the course of a college biology. To find out more about how to teach about evolution, please see 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 looking back, studying fossils, comparing species, and studying living organisms. Evolution is not a past event, but a process that continues today. The virus reinvents itself to avoid new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior in the wake of a changing world. The resulting changes are often visible. It wasn't until the 1980s that biologists began realize that natural selection was in action. The key to this is that different traits confer an individual rate of survival and reproduction, and they can be 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 quickly become more common than other alleles. As time passes, this could mean that the number of moths with black pigmentation in a population could increase. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. Monitoring evolutionary changes in action is much easier when a species has a rapid turnover of its generation such as bacteria. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from one strain. Samples from each population were taken frequently and more than 500.000 generations of E.coli have been observed to have passed. Lenski's research has revealed that mutations can alter the rate at which change occurs and the effectiveness of a population's reproduction. It also proves that evolution is slow-moving, a fact that some people find hard 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. That's because the use of pesticides creates a selective pressure that favors individuals who have resistant genotypes. The rapid pace at which evolution can take place has led to an increasing appreciation of its importance in a world that is shaped by human activities, including climate changes, pollution and the loss of habitats that prevent many species from adjusting. Understanding the evolution process can help us make smarter choices about the future of our planet as well as the life of its inhabitants.