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The Academy's Evolution Site Biology is a key concept in biology. The Academies are involved in helping those interested in science to comprehend the evolution theory and how it is incorporated throughout all fields of scientific research. This site offers a variety of sources for students, teachers, and general readers on evolution. It includes key video clips from NOVA and the WGBH-produced science programs on DVD. Tree of Life The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It appears in many spiritual traditions and cultures as a symbol of unity and love. It also has practical uses, like providing a framework to understand the history of species and how they react to changes in environmental conditions. Early attempts to describe the world of biology were founded on categorizing organisms on their metabolic and physical characteristics. These methods, which rely on the sampling of different parts of organisms, or DNA fragments, have significantly increased the diversity of a Tree of Life2. The trees are mostly composed by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4. By avoiding the need for direct experimentation and observation, genetic techniques have enabled us to represent the Tree of Life in a much more accurate way. In particular, molecular methods allow us to construct trees by using sequenced markers, such as the small subunit ribosomal gene. Despite the massive expansion 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 are typically present in a single sample5. Recent analysis of all genomes has produced a rough draft of a Tree of Life. This includes a large number of bacteria, archaea and other organisms that haven't yet been isolated or their diversity is not fully understood6. This expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if particular habitats need special protection. This information can be utilized in a variety of ways, from identifying the most effective medicines to combating disease to enhancing crops. It is also beneficial to conservation efforts. It can aid biologists in identifying the areas most likely to contain cryptic species that could have important metabolic functions that may be at risk from anthropogenic change. While funding to protect biodiversity are important, the best method to protect the world's biodiversity is to empower the people of developing nations with the knowledge they need to act locally and promote conservation. Phylogeny A phylogeny (also called an evolutionary tree) depicts the relationships between different organisms. Using molecular data, morphological similarities and differences or ontogeny (the course of development of an organism) scientists can create an phylogenetic tree that demonstrates the evolutionary relationship between taxonomic groups. The phylogeny of a tree plays an important role in understanding biodiversity, genetics and evolution. A basic phylogenetic tree (see Figure PageIndex 10 ) identifies the relationships between organisms that share similar traits that have evolved from common ancestral. These shared traits are either analogous or homologous. 무료에볼루션 are identical in their evolutionary roots while analogous traits appear similar, but do not share the identical origins. Scientists put similar traits into a grouping called a clade. For instance, all of the species in a clade share the trait of having amniotic egg and evolved from a common ancestor that had these eggs. The clades are then connected to create a phylogenetic tree to identify organisms that have the closest relationship to. Scientists make use of molecular DNA or RNA data to build a phylogenetic chart that is more accurate and precise. This data is more precise than the morphological data and gives evidence of the evolutionary history of an organism or group. The analysis of molecular data can help researchers identify the number of species who share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationships between species are influenced by many factors, including phenotypic flexibility, a type of behavior that alters in response to specific environmental conditions. This can make a trait appear more similar to a species than to another which can obscure the phylogenetic signal. However, this problem can be solved through the use of techniques such as cladistics which include a mix of analogous and homologous features into the tree. In addition, phylogenetics can help predict the time and pace of speciation. This information can aid conservation biologists in making choices about which species to safeguard from extinction. Ultimately, it is the preservation of phylogenetic diversity that will result in an ecologically balanced and complete ecosystem. 에볼루션사이트 of evolution is that organisms acquire different features over time based on their interactions with their environments. A variety of theories about evolution have been proposed by a variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve gradually according to its needs and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that can be passed on to offspring. In the 1930s & 1940s, concepts from various fields, such as natural selection, genetics & particulate inheritance, were brought together to form a contemporary synthesis of evolution theory. This describes how evolution is triggered by the variation in genes within a population and how these variations change with time due to natural selection. This model, which encompasses mutations, genetic drift as well as gene flow and sexual selection can be mathematically described. Recent developments in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species through mutation, genetic drift, and reshuffling genes during sexual reproduction, as well as by migration between populations. These processes, as well as others, such as the directional selection process and the erosion of genes (changes in the frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time, as well as changes in phenotype (the expression of genotypes in individuals). Students can better understand 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 increased their understanding of evolution during an undergraduate biology course. For more details about how to teach evolution read The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily as a Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Traditionally, scientists have studied evolution through looking back, studying fossils, comparing species, and observing living organisms. But evolution isn't a thing that happened in the past; it's an ongoing process happening in the present. Bacteria transform and resist antibiotics, viruses re-invent themselves and elude new medications, and animals adapt their behavior in response to a changing planet. The resulting changes are often evident. But it wasn't until the late 1980s that biologists understood that natural selection can be observed in action as well. The key is that different traits have different rates of survival and reproduction (differential fitness), and can be passed down from one generation to the next. In the past, if one allele – the genetic sequence that determines colour – appeared in a population of organisms that interbred, it could become more prevalent 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. Observing evolutionary change in action is easier when a particular species has a rapid generation turnover, as with bacteria. Since 1988, Richard Lenski, a biologist, has been tracking 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 been observed to have passed. Lenski's research has revealed that mutations can alter the rate of change and the rate at which a population reproduces. It also proves that evolution is slow-moving, a fact that some people are unable to accept. Microevolution can also be seen in the fact that mosquito genes for pesticide resistance are more common in populations where insecticides have been used. That's because the use of pesticides creates a selective pressure that favors those who have resistant genotypes. The rapidity of evolution has led to a growing awareness of its significance especially in a planet that is largely shaped by human activity. This includes climate change, pollution, and habitat loss that hinders many species from adapting. Understanding evolution can help us make better choices about the future of our planet as well as the life of its inhabitants.