Profile
Are The Advances In Technology Making Evolution Site Better Or Worse? The Academy's Evolution Site Biological evolution is a central concept in biology. The Academies have been for a long time involved in helping people who are interested in science comprehend the theory of evolution and how it affects all areas of scientific exploration. This site provides a wide range of tools for teachers, students and general readers of 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 appears in many religions and cultures as a symbol of unity and love. It also has important practical uses, like providing a framework for understanding the history of species and how they respond to changes in environmental conditions. Early attempts to describe the world of biology were founded on categorizing organisms on their physical and metabolic characteristics. These methods, which rely on the sampling of different parts of organisms or short fragments of DNA have significantly increased the diversity of a tree of Life2. These trees are largely composed of eukaryotes, while bacterial diversity is vastly underrepresented3,4. By avoiding the necessity for direct experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a more precise way. Trees can be constructed using molecular techniques such as the small subunit ribosomal gene. Despite the massive expansion of the Tree of Life through genome sequencing, a large amount of biodiversity remains to be discovered. This is particularly true of microorganisms, which can be difficult to cultivate and are typically only present in a single sample5. A recent analysis of all genomes has produced an unfinished draft of a Tree of Life. This includes a wide range of archaea, bacteria, and other organisms that haven't yet been identified or the diversity of which is not thoroughly understood6. The expanded Tree of Life can be used to determine the diversity of a specific area and determine if particular habitats need special protection. This information can be utilized in a variety of ways, including finding new drugs, battling diseases and enhancing crops. It is also useful for conservation efforts. It can aid biologists in identifying areas most likely to have species that are cryptic, which could perform important metabolic functions and are susceptible to human-induced change. While funds to protect biodiversity are important, the best method to protect the biodiversity of the world is to equip more people in developing countries with the necessary knowledge to take action locally and encourage conservation. Phylogeny A phylogeny (also known as an evolutionary tree) shows the relationships between organisms. By using molecular information similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can construct an phylogenetic tree that demonstrates the evolution of taxonomic groups. Phylogeny plays a crucial role in understanding biodiversity, genetics and evolution. A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms that have similar traits and evolved from a common ancestor. These shared traits can be analogous or homologous. Homologous traits share their underlying evolutionary path and analogous traits appear similar, but do not share the same origins. Scientists group similar traits into a grouping known as a clade. For instance, all of the organisms that make up a clade share the characteristic of having amniotic egg and evolved from a common ancestor that had these eggs. A phylogenetic tree is then constructed by connecting clades to identify the organisms that are most closely related to one another. For a more precise and accurate phylogenetic tree scientists rely on molecular information from DNA or RNA to establish the connections between organisms. This information is more precise and provides evidence of the evolutionary history of an organism. Researchers can use Molecular Data to calculate the evolutionary age of organisms and identify the number of organisms that share the same ancestor. The phylogenetic relationships of a species can be affected by a number of factors such as the phenotypic plasticity. This is a type behavior that changes due to specific environmental conditions. This can cause a trait to appear more similar to one species than another, clouding the phylogenetic signal. This problem can be mitigated by using cladistics. 에볼루션코리아 is a method that incorporates the combination of homologous and analogous features in the tree. Furthermore, phylogenetics may aid in predicting the length and speed of speciation. This information can assist conservation biologists in making decisions about which species to safeguard from extinction. Ultimately, it is the preservation of phylogenetic diversity which will create an ecologically balanced and complete ecosystem. 에볼루션코리아 behind evolution is that organisms change over time as a result of 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 could develop according to its own requirements, 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 usage or non-use of traits can lead to changes that are passed on to the next generation. In the 1930s and 1940s, theories from a variety of fields -- including genetics, natural selection, and particulate inheritance -- came together to form the modern evolutionary theory, which defines how evolution occurs through the variations of genes within a population and how these variants change over time due to natural selection. This model, called genetic drift mutation, gene flow and sexual selection, is a cornerstone of the current evolutionary biology and can be mathematically explained. Recent advances in evolutionary developmental biology have shown how variation can be introduced to a species via mutations, genetic drift or reshuffling of genes in sexual reproduction and the movement between populations. These processes, along with other ones like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time), can lead to evolution that is defined as change in the genome of the species over time and the change in phenotype over time (the expression of the genotype within the individual). Students can gain a better understanding of the concept of phylogeny by using evolutionary thinking throughout all areas of biology. In a recent study conducted by Grunspan and co. It was demonstrated that teaching students about the evidence for evolution boosted their understanding of evolution in the course of a college biology. For more information on how to teach about evolution, please read The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education. Evolution in Action Traditionally, scientists have studied evolution by looking back, studying fossils, comparing species and observing living organisms. However, evolution isn't something that happened in the past. It's an ongoing process that is that is taking place today. Bacteria transform and resist antibiotics, viruses re-invent themselves and are able to evade new medications and animals change their behavior to a changing planet. The resulting changes are often visible. But it wasn't until the late-1980s that biologists realized that natural selection can be seen in action, as well. The key is the fact that different traits can confer the ability to survive at different rates and reproduction, and they can be passed on from one generation to another. In the past, if one particular allele, the genetic sequence that determines coloration--appeared in a group of interbreeding species, it could rapidly become more common than all other alleles. As time passes, that could mean that the number of black moths within a 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 fast generation turnover like bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples of each are taken on a regular basis and over 500.000 generations have been observed. 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 shows that evolution takes time, a fact that is difficult for some to accept. Microevolution can also be seen in the fact that mosquito genes that confer resistance to pesticides are more prevalent in populations where insecticides are used. This is due to pesticides causing a selective pressure which favors individuals who have resistant genotypes. The speed of evolution taking place has led to a growing recognition of its importance in a world that is shaped by human activity--including climate change, pollution, and the loss of habitats which prevent the species from adapting. Understanding the evolution process will help us make better decisions about the future of our planet, as well as the life of its inhabitants.
Forum Role: Participant
Topics Started: 0
Replies Created: 0