The email you entered is already receiving Daily Bits Emails!
The Academy's Evolution Site The concept of biological evolution is among the most important concepts in biology. The Academies are committed to helping those interested in the sciences understand evolution theory and how it can be applied throughout all fields of scientific research. This site provides a wide range of sources for teachers, students as well as general readers about 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, represents the interconnectedness of all life. It is used in many religions and cultures as an emblem of unity and love. It has numerous practical applications as well, such as providing a framework to understand the history of species and how they respond to changes in environmental conditions. The first attempts at depicting the biological world focused on the classification of organisms into distinct categories which were identified by their physical and metabolic characteristics1. ???? ??? ??? , which rely on the sampling of different parts of living organisms or 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. By avoiding the necessity for direct experimentation and observation genetic techniques have allowed us to represent the Tree of Life in a more precise manner. Particularly, molecular methods allow us to build trees by using sequenced markers, such as the small subunit ribosomal gene. Despite the rapid expansion of the Tree of Life through genome sequencing, a lot of biodiversity remains to be discovered. This is particularly true of microorganisms, which are difficult to cultivate and are often only found in a single sample5. A recent study of all genomes that are known has produced a rough draft version of the Tree of Life, including a large number of bacteria and archaea that are not isolated and their diversity is not fully understood6. The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, which can help to determine if specific habitats require protection. ???? ??? can be used in a variety of ways, including identifying new drugs, combating diseases and improving crops. This information is also extremely beneficial to conservation efforts. It can aid biologists in identifying areas most likely to be home to species that are cryptic, which could have important metabolic functions and are susceptible to the effects of human activity. While funds to protect biodiversity are essential, the best method to protect the world's biodiversity is to empower more people in developing countries with the information they require to act locally and support conservation. Phylogeny A phylogeny (also called an evolutionary tree) depicts the relationships between different organisms. Using molecular data similarities and differences in morphology or ontogeny (the course of development of an organism), scientists can build a phylogenetic tree which illustrates the evolutionary relationship between taxonomic groups. Phylogeny is essential in understanding biodiversity, evolution and genetics. A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that evolved from common ancestral. These shared traits may be analogous or homologous. Homologous characteristics are identical in their evolutionary path. Analogous traits could appear like they are but they don't share the same origins. Scientists group similar traits into a grouping referred to as a the clade. All organisms in a group have a common characteristic, for example, amniotic egg production. They all evolved from an ancestor who had these eggs. The clades then join to form a phylogenetic branch that can determine the organisms with the closest relationship to. For a more precise and accurate phylogenetic tree, scientists use molecular data 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. The analysis of molecular data can help researchers determine the number of organisms that share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationships between organisms can be influenced by several factors, including phenotypic flexibility, an aspect of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar to one species than to another and obscure the phylogenetic signals. However, this issue can be cured by the use of methods like cladistics, which combine homologous and analogous features into the tree. Additionally, phylogenetics can help predict the length and speed of speciation. This information can aid conservation biologists to make decisions about which species they should protect from extinction. In the end, it's the preservation of phylogenetic diversity which will lead to a complete and balanced ecosystem. Evolutionary Theory The main idea behind evolution is that organisms acquire various characteristics over time as a result of their interactions with their environment. Many scientists have come up with theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could develop according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or non-use of traits can lead to changes that are passed on to the In the 1930s and 1940s, ideas from a variety of fields--including genetics, natural selection and particulate inheritance--came together to create the modern synthesis of evolutionary theory that explains how evolution happens through the variations of genes within a population and how those variations change over time as a result of natural selection. This model, which encompasses genetic drift, mutations as well as gene flow and sexual selection, can be mathematically described mathematically. Recent discoveries in the field of evolutionary developmental biology have demonstrated that genetic variation can be introduced into a species through genetic drift, mutation, and reshuffling genes during sexual reproduction, and also through the movement of populations. These processes, as well as other ones like the directional selection process and the erosion of genes (changes in frequency of genotypes over time) can result in evolution. Evolution is defined as changes in the genome over time as well as changes in the phenotype (the expression of genotypes in an individual). Incorporating evolutionary thinking into all areas of biology education can improve student understanding of the concepts of phylogeny and evolutionary. In a study by Grunspan et al. It was found that teaching students about the evidence for evolution boosted their acceptance of evolution during an undergraduate biology course. For more information about how to teach evolution read The Evolutionary Power of Biology 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 by 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, that is taking place today. Bacteria mutate and resist antibiotics, viruses evolve and are able to evade new medications and animals alter their behavior to a changing planet. The resulting changes are often visible. But it wasn't until the late 1980s that biologists understood that natural selection could be observed in action as well. The main reason is that different traits can confer the ability to survive at different rates and reproduction, and can be passed down from one generation to the next. In the past, if an allele - the genetic sequence that determines color - appeared in a population of organisms that interbred, it might become more prevalent than any other allele. As time passes, that could mean the number of black moths within the population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms. Monitoring evolutionary changes in action is easier when a species has a rapid turnover of its generation like bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from a single strain. Samples from each population were taken frequently and more than 500.000 generations of E.coli have passed. Lenski's research has revealed that a mutation can dramatically alter the efficiency with which a population reproduces--and so, the rate at which it evolves. It also shows that evolution is slow-moving, a fact that some are unable to accept. Microevolution can also be seen in the fact that mosquito genes for resistance to pesticides are more prevalent in populations that have used insecticides. This is due to pesticides causing a selective pressure which favors those with resistant genotypes. The rapidity of evolution has led to a greater appreciation of its importance, especially in a world which is largely shaped by human activities. This includes climate change, pollution, and habitat loss, which prevents many species from adapting. Understanding evolution will assist you in making better choices about the future of our planet and its inhabitants.
Member since: Wednesday, January 1, 2025
Website: http://psicolinguistica.letras.ufmg.br/wiki/index.php/15-Great-Documentaries-About-Evolution-Baccarat-Site-m
