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The Academy's Evolution Site Biological evolution is one of the most central concepts in biology. The Academies have long been involved in helping people who are interested in science understand the theory of evolution and how it affects all areas of scientific exploration. 에볼루션 무료체험 provides teachers, students and general readers with a variety of learning resources about evolution. It contains important video clips from NOVA and WGBH-produced science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is a symbol of love and harmony in a variety of cultures. It also has practical applications, such as providing a framework for understanding the history of species and how they react to changing environmental conditions. The first attempts to depict the biological world were based on categorizing organisms based on their metabolic and physical characteristics. These methods, which depend on the sampling of different parts of organisms, or DNA fragments have significantly increased the diversity of a tree of Life2. However these trees are mainly made up of eukaryotes. Bacterial diversity is still largely unrepresented3,4. By avoiding the need for direct observation and experimentation, genetic techniques have allowed us to depict the Tree of Life in a more precise manner. We can create trees by using molecular methods like the small-subunit ribosomal gene. The Tree of Life has been greatly expanded thanks to genome sequencing. However there is still a lot of diversity to be discovered. This is particularly the case for microorganisms which are difficult to cultivate and which are usually only found in a single specimen5. Recent analysis of all genomes resulted in a rough draft of a Tree of Life. 에볼루션 코리아 includes a variety of archaea, bacteria, and other organisms that haven't yet been isolated, or whose diversity has not been well understood6. This expanded Tree of Life can be used to assess the biodiversity of a specific region and determine if particular habitats require special protection. The information can be used in a range of ways, from identifying the most effective treatments to fight disease to enhancing the quality of the quality of crops. The information is also beneficial to conservation efforts. It can help biologists identify areas that are most likely to have cryptic species, which could have vital metabolic functions, and could be susceptible to changes caused by humans. While funds 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 known as an evolutionary tree) depicts the relationships between different organisms. By using molecular information, morphological similarities and differences, or ontogeny (the process of the development of an organism) scientists can construct a phylogenetic tree which illustrates the evolution of taxonomic categories. Phylogeny is crucial in understanding biodiversity, evolution and genetics. A basic phylogenetic tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that evolved from common ancestors. These shared traits could be analogous, or homologous. Homologous traits are similar in their evolutionary journey. Analogous traits could appear like they are however they do not have the same ancestry. Scientists group similar traits together into a grouping referred to as a Clade. Every organism in a group share a characteristic, for example, amniotic egg production. They all came from an ancestor who had these eggs. The clades are then linked to create a phylogenetic tree to determine the organisms with the closest relationship. To create a more thorough and precise phylogenetic tree scientists rely on molecular information from DNA or RNA to establish the relationships between organisms. This information is more precise and gives evidence of the evolution history of an organism. Molecular data allows researchers to determine the number of organisms who share a common ancestor and to estimate their evolutionary age. The phylogenetic relationships of organisms are influenced by many factors including phenotypic plasticity, a kind of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar in one species than other species, which can obscure the phylogenetic signal. However, this issue can be solved through the use of methods such as cladistics which combine homologous and analogous features into the tree. Furthermore, phylogenetics may help predict the duration and rate of speciation. This information will assist conservation biologists in making choices about which species to safeguard from disappearance. Ultimately, it is the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced. Evolutionary Theory The fundamental concept of evolution is that organisms acquire distinct characteristics over time as a result of their interactions with their environments. Many scientists have proposed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would evolve according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1844-1829), who believed that the usage or non-use of certain traits can result in changes that are passed on to the next generation. In the 1930s & 1940s, theories from various fields, such as genetics, natural selection, and particulate inheritance, came together to form a modern evolutionary theory. This describes how evolution occurs by the variation of genes in the population, and how these variants change with time due to natural selection. This model, called genetic drift, mutation, gene flow, and sexual selection, is the foundation of current evolutionary biology, and can be mathematically described. Recent advances in the field of evolutionary developmental biology have revealed how variations can be introduced to a species through genetic drift, mutations or reshuffling of genes in sexual reproduction, and even migration between populations. These processes, in conjunction with others such as directional selection and gene erosion (changes in frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes in an individual). Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking throughout all areas of biology. In a recent study by Grunspan and co., it was shown 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 about evolution look up The Evolutionary Potential 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 by studying fossils, comparing species, and observing living organisms. Evolution is not a past event, but a process that continues today. Bacteria evolve and resist antibiotics, viruses reinvent themselves and are able to evade new medications and animals alter their behavior in response to the changing climate. 에볼루션 코리아 resulting changes are often evident. It wasn't until the 1980s that biologists began to realize that natural selection was in action. The main reason is that different traits result in a different rate of survival and reproduction, and they can be passed on from generation to generation. In the past, if a certain allele – the genetic sequence that determines colour – was found in a group of organisms that interbred, it could become more prevalent than any other allele. In time, this could mean that the number of moths sporting black pigmentation in a group 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 a species, such as bacteria, has a rapid generation turnover. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain. samples of each population are taken on a regular basis and over 500.000 generations have passed. Lenski's work has shown that mutations can alter the rate of change and the rate at which a population reproduces. It also shows that evolution takes time, a fact that some find hard to accept. Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more common in populations where insecticides are used. This is due to the fact that the use of pesticides creates a selective pressure that favors people who have 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 hinder many species from adjusting. Understanding the evolution process can aid you in making better decisions regarding the future of the planet and its inhabitants.