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The Academy's Evolution Site Biological evolution is one of the most important concepts in biology. The Academies have been active for a long time in helping people who are interested in science comprehend the concept of evolution and how it affects all areas of scientific research. This site provides students, teachers and general readers with a range of learning resources about evolution. It includes the most important video clips from NOVA and WGBH-produced science programs on DVD. Tree of Life The Tree of Life is an ancient symbol that symbolizes the interconnectedness of all life. It appears in many cultures and spiritual beliefs as a symbol of unity and love. It has many practical applications as well, including providing a framework to understand the history of species and how they react to changing environmental conditions. Early attempts to describe the biological world were based on categorizing organisms based on their physical and metabolic characteristics. These methods, based on sampling of different parts of living organisms or on sequences of small fragments of their DNA, greatly increased the variety of organisms that could be represented in a tree of life2. However these trees are mainly composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4. In avoiding the necessity of direct observation and experimentation, genetic techniques have enabled us to depict the Tree of Life in a much more accurate way. We can create trees using molecular techniques, such as the small-subunit ribosomal gene. Despite the massive expansion of the Tree of Life through genome sequencing, a lot of biodiversity is waiting to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are often only found in a single specimen5. A recent study of all genomes that are known has produced a rough draft of the Tree of Life, including a large number of archaea and bacteria that have not been isolated and which are not well understood. This expanded Tree of Life is particularly useful for assessing the biodiversity of an area, assisting to determine if specific habitats require special protection. The information is useful in a variety of ways, including finding new drugs, battling diseases and enhancing crops. The information is also incredibly useful in conservation efforts. It can aid biologists in identifying those areas that are most likely contain cryptic species that could have significant metabolic functions that could be at risk of anthropogenic changes. Although funds to protect biodiversity are crucial but the most effective way to ensure the preservation of biodiversity around the world is for more people in developing countries to be empowered with the knowledge to take action locally to encourage conservation from within. Phylogeny A phylogeny, also called an evolutionary tree, reveals the connections between various groups of organisms. Utilizing molecular data similarities and differences in morphology or ontogeny (the process of the development of an organism), scientists can build an phylogenetic tree that demonstrates the evolutionary relationship between taxonomic categories. Phylogeny is essential in understanding biodiversity, evolution and genetics. A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms that have similar traits and have evolved from an ancestor with common traits. These shared traits may be homologous, or analogous. Homologous traits are the same in their evolutionary journey. Analogous traits could appear similar however they do not have the same ancestry. Scientists group similar traits into a grouping known as a clade. For instance, all the organisms in a clade share the trait of having amniotic eggs and evolved from a common ancestor which had eggs. The clades are then linked to form a phylogenetic branch that can determine which organisms have the closest relationship. Scientists utilize molecular DNA or RNA data to create a phylogenetic chart that is more precise and precise. This data is more precise than morphological data and gives evidence of the evolutionary background of an organism or group. Researchers can use Molecular Data to estimate the age of evolution of organisms and determine how many organisms have the same ancestor. The phylogenetic relationships of organisms are influenced by many factors, including phenotypic flexibility, an aspect of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more similar to one species than another and obscure the phylogenetic signals. This problem can be mitigated by using cladistics, which incorporates a combination of homologous and analogous traits in the tree. Additionally, 에볼루션 코리아 determine the duration and speed of speciation. This information can assist conservation biologists in making decisions about which species to protect from the threat of extinction. In the end, it's the preservation of phylogenetic diversity which will create an ecologically balanced and complete ecosystem. Evolutionary Theory The central theme in evolution is that organisms change over time due to their interactions with their environment. Many scientists have proposed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would develop according to its own needs as well as the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern taxonomy system that is hierarchical and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of certain traits can result in changes that are passed on to the next generation. In the 1930s and 1940s, theories from various areas, including natural selection, genetics & particulate inheritance, came together to create a modern synthesis of evolution theory. This explains how evolution is triggered by the variation in genes within the population, and how these variations change with time due to natural selection. This model, known as genetic drift, mutation, gene flow and sexual selection, is a cornerstone of current evolutionary biology, and can be mathematically explained. 에볼루션 바카라 무료 in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species via mutation, genetic drift and reshuffling of genes in sexual reproduction, and also through migration between populations. These processes, along with others such as directional selection or genetic erosion (changes in the frequency of an individual's genotype over time) can result in evolution that is defined as change in the genome of the species over time and also the change in phenotype over time (the expression of the genotype in an individual). Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny as well as evolution. In a recent study conducted by Grunspan et al. It was demonstrated that teaching students about the evidence for evolution boosted their understanding of evolution during the course of a college biology. For more details on how to teach evolution, see The Evolutionary Power of Biology in All Areas of Biology or Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Traditionally, scientists have studied evolution through looking back—analyzing fossils, comparing species, and observing living organisms. But evolution isn't just something that occurred in the past; it's an ongoing process happening right now. Bacteria mutate and resist antibiotics, viruses evolve and are able to evade new medications and animals alter their behavior to the changing environment. The results are often apparent. It wasn't until late 1980s that biologists began realize that natural selection was also at work. The key is that different traits confer different rates of survival and reproduction (differential fitness) and can be passed down from one generation to the next. In the past, if an allele – the genetic sequence that determines colour – was found in a group of organisms that interbred, it could be more common than other allele. In time, this could mean that the number of black moths in a particular population could rise. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. It is easier to track evolutionary change when a species, such as bacteria, has a rapid generation turnover. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from one strain. The samples of each population have been taken regularly and more than 500.000 generations of E.coli have passed. Lenski's work has demonstrated that a mutation can profoundly alter the rate at the rate at which a population reproduces, and consequently, the rate at which it changes. It also shows that evolution takes time, a fact that many find difficult to accept. Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more prevalent in areas where insecticides are used. This is because pesticides cause an enticement that favors individuals who have resistant genotypes. The rapidity of evolution has led to a greater recognition of its importance especially in a planet shaped largely by human activity. This includes climate change, pollution, and habitat loss that prevents many species from adapting. Understanding the evolution process can help us make better decisions regarding the future of our planet and the lives of its inhabitants.