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The Academy's Evolution Site Biology is a key concept in biology. The Academies are involved in helping those who are interested in the sciences learn about the theory of evolution and how it is permeated in all areas of scientific research. This site provides students, teachers and general readers with a variety of learning resources about 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 represents the interconnectedness of all life. It is an emblem of love and unity across many cultures. 에볼루션 바카라 has important practical applications, like providing a framework to understand the evolution of species and how they react to changes in the environment. The first attempts to depict the biological world were built on categorizing organisms based on their metabolic and physical characteristics. These methods, which relied on the sampling of various parts of living organisms or on sequences of small DNA fragments, significantly increased the variety that could be represented 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 depict the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular methods allow us to construct trees by using sequenced markers, such as the small subunit of ribosomal RNA gene. Despite the dramatic growth of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is especially true of microorganisms, which can be difficult to cultivate and are usually only found in a single sample5. A recent analysis of all genomes known to date has produced a rough draft version of the Tree of Life, including many bacteria and archaea that are not isolated and their diversity is not fully understood6. The expanded Tree of Life can be used to evaluate the biodiversity of a specific region and determine if particular habitats require special protection. This information can be utilized in a range of ways, from identifying the most effective medicines to combating disease to enhancing the quality of the quality of crops. This information is also useful to conservation efforts. It helps biologists discover areas that are likely to be home to cryptic species, which may perform important metabolic functions and be vulnerable to changes caused by humans. Although funds to safeguard biodiversity are vital but the most effective way to preserve the world's biodiversity is for more people in developing countries to be equipped with the knowledge to act locally in order to promote conservation from within. Phylogeny A phylogeny is also known as an evolutionary tree, reveals the connections between different groups of organisms. By using molecular information similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree which illustrates the evolutionary relationships between taxonomic groups. The concept of phylogeny is fundamental to understanding evolution, biodiversity and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that evolved from common ancestors. These shared traits can be analogous or homologous. Homologous traits are similar in their evolutionary origins and analogous traits appear similar but do not have the same ancestors. Scientists group similar traits together into a grouping known as a clade. For example, all of the species in a clade have the characteristic of having amniotic eggs. They evolved from a common ancestor who had eggs. The clades then join to form a phylogenetic branch to identify organisms that have the closest relationship to. To create a more thorough and accurate phylogenetic tree, scientists use molecular data from DNA or RNA to determine the relationships among organisms. This information is more precise and gives evidence of the evolution of an organism. Researchers can use Molecular Data to calculate the evolutionary age of organisms and identify the number of organisms that share an ancestor common to all. Phylogenetic relationships can be affected by a number of factors such as the phenomenon of phenotypicplasticity. This is a type of behaviour that can change in response to unique environmental conditions. This can cause a trait to appear more similar to one species than another, obscuring the phylogenetic signal. However, this problem can be cured by the use of methods like cladistics, which include a mix of homologous and analogous features into the tree. Additionally, phylogenetics can help determine the duration and speed at which speciation occurs. This information can aid conservation biologists to decide the species they should safeguard from extinction. In the end, it's the preservation of phylogenetic diversity which will lead to an ecosystem that is complete and balanced. Evolutionary Theory The fundamental concept of evolution is that organisms acquire various characteristics over time based on 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 an organism could develop according to its own requirements 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 usage or non-use of traits can cause changes that are passed on to the In the 1930s & 1940s, ideas from different fields, such as genetics, natural selection and particulate inheritance, merged to create a modern theorizing of evolution. This explains how evolution is triggered by the variation of genes in the population, and how these variants change over time as a result of natural selection. This model, which includes mutations, genetic drift as well as gene flow and sexual selection, can be mathematically described mathematically. Recent discoveries in the field of evolutionary developmental biology have shown the ways in which variation can be introduced to a species by mutations, genetic drift, reshuffling genes during sexual reproduction and the movement between populations. These processes, as well as others such as directional selection or genetic erosion (changes in the frequency of the genotype over time) can result in evolution which is defined by changes in the genome of the species over time and the change in phenotype as time passes (the expression of that genotype in an individual). Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all areas of biology. In a study by Grunspan et al. It was found that teaching students about the evidence for evolution boosted their understanding of evolution during the course of a college biology. To learn more about how to teach about evolution, please see The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution in Life Sciences Education. Evolution in Action Traditionally scientists have studied evolution by studying fossils, comparing species and studying living organisms. Evolution is not a past event, but an ongoing process. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals adapt their behavior because of the changing environment. The changes that result are often apparent. It wasn't until the 1980s that biologists began to realize that natural selection was also in action. The key to this is that different traits confer an individual rate of survival and reproduction, and they can be passed on from generation to generation. In the past when one particular allele—the genetic sequence that determines coloration—appeared in a population of interbreeding species, it could rapidly become more common than other alleles. As time passes, this could mean that the number of moths with black pigmentation may increase. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. The ability to observe evolutionary change 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 of each population have been collected frequently and more than 500.000 generations of E.coli have been observed to have passed. Lenski's research has demonstrated that mutations can alter the rate at which change occurs and the rate at which a population reproduces. 에볼루션바카라사이트 shows evolution takes time, a fact that is difficult for some to accept. Another example of microevolution is the way mosquito genes for resistance to pesticides show up more often in populations where insecticides are employed. This is because the use of pesticides causes a selective pressure that favors those who have resistant genotypes. The rapid pace of evolution taking place has led to a growing appreciation of its importance in a world that is shaped by human activity, including climate change, pollution and the loss of habitats that hinder many species from adapting. Understanding the evolution process will help us make better decisions regarding the future of our planet, and the lives of its inhabitants.