tankmap1

The Academy's Evolution Site Biology is one of the most central concepts in biology. The Academies are involved in helping those interested in science learn about the theory of evolution and how it is permeated in all areas of scientific research. This site provides teachers, students and general readers with a wide range of learning resources on evolution. It contains key 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 is an emblem of love and harmony in a variety of cultures. It also has important practical applications, such as providing a framework to understand the evolution of species and how they react to changing environmental conditions. Early approaches to depicting the biological world focused on the classification of organisms into distinct categories which were distinguished by their physical and metabolic characteristics1. These methods, which are based on the collection of various parts of organisms or short DNA fragments, have greatly increased the diversity of a tree of Life2. However these trees are mainly composed of eukaryotes; bacterial diversity is still largely unrepresented3,4. Genetic techniques have significantly expanded our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. Trees can be constructed using molecular methods, such as the small-subunit ribosomal gene. Despite the rapid growth of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is especially true of microorganisms that are difficult to cultivate and are usually only present in a single sample5. A recent analysis of all genomes that are known has produced a rough draft of the Tree of Life, including numerous bacteria and archaea that are not isolated and their diversity is not fully understood6. The expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine if specific habitats require special protection. This information can be used in a variety of ways, from identifying new treatments to fight disease to improving crops. It is also useful for conservation efforts. It helps biologists discover areas that are most likely to be home to cryptic species, which could have vital metabolic functions and be vulnerable to human-induced change. Although funds to protect biodiversity are essential, ultimately the best way to protect the world's biodiversity is for more people living in developing countries to be equipped with the knowledge to act locally in order to promote conservation from within. Phylogeny A phylogeny, also called an evolutionary tree, reveals the connections between groups of organisms. By using molecular information as well as morphological similarities and distinctions, or ontogeny (the process of the development of an organism) scientists can create a phylogenetic tree which illustrates the evolutionary relationships between taxonomic groups. The role of phylogeny is crucial in understanding biodiversity, genetics and evolution. A basic phylogenetic Tree (see Figure PageIndex 10 Finds the connections between organisms that have similar traits and evolved from an ancestor with common traits. These shared traits are either homologous or analogous. Homologous traits are the same in terms of their evolutionary journey. Analogous traits might appear similar, but they do not have the same origins. Scientists group similar traits together into a grouping referred to as a Clade. For example, all of the species in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor which had these eggs. The clades are then connected to form a phylogenetic branch that can determine which organisms have the closest relationship to. Scientists utilize DNA or RNA molecular data to build a phylogenetic chart that is more precise and precise. This data is more precise than the morphological data and provides evidence of the evolution history of an organism or group. The use of molecular data lets researchers determine the number of species that share an ancestor common to them and estimate their evolutionary age. The phylogenetic relationships between species can be influenced by several factors including phenotypic plasticity, a type 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 problem can be solved through the use of methods such as cladistics which include a mix of homologous and analogous features into the tree. Furthermore, phylogenetics may aid in predicting the duration and rate 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 conservation of phylogenetic variety which will create an ecosystem that is complete and balanced. Evolutionary Theory The main idea behind evolution is that organisms develop various characteristics over time based on their interactions with their environments. Many scientists have developed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would evolve according to its individual needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern taxonomy system that is hierarchical, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of traits can lead to changes that can be passed on to future generations. In the 1930s and 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance—came together to form the current evolutionary theory, which defines how evolution is triggered by the variations of genes within a population and how those variations change over time as a result of natural selection. This model, which includes mutations, genetic drift as well as gene flow and sexual selection is mathematically described mathematically. Recent developments in the field of evolutionary developmental biology have revealed that genetic variation can be introduced into a species by mutation, genetic drift and reshuffling genes during sexual reproduction, and also through migration between populations. These processes, as well as others such as directional selection or genetic erosion (changes in the frequency of a genotype over time) can lead to evolution, which is defined by change in the genome of the species over time and the change in phenotype over time (the expression of the genotype within the individual). Incorporating evolutionary thinking into all aspects of biology education can improve student understanding of the concepts of phylogeny and evolutionary. In a recent study conducted by Grunspan and colleagues., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during a college-level course in biology. To find out more about how to teach about evolution, please look up The Evolutionary Potential in all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing the Concept of Evolution into Life Sciences Education. Evolution in Action Traditionally scientists have studied evolution through studying fossils, comparing species, and studying living organisms. Evolution is not a distant moment; it is a process that continues today. Bacteria mutate and resist antibiotics, viruses re-invent themselves and escape new drugs and animals alter their behavior in response to the changing climate. The resulting changes are often evident. It wasn't until the late 1980s that biologists began realize that natural selection was in action. The key is that different traits have different rates of survival and reproduction (differential fitness), and can be transferred from one generation to the next. In the past, if a certain allele – the genetic sequence that determines colour was present in a population of organisms that interbred, it could be more common than any other allele. In time, this could mean that the number of moths sporting black pigmentation in a population could increase. The same is true for many other characteristics—including morphology and behavior—that vary among populations of organisms. 에볼루션사이트 to observe evolutionary change is easier when a particular species has a rapid turnover of its generation such as bacteria. Since 1988, Richard Lenski, a biologist, has been tracking twelve populations of E.coli that are descended from one strain. Samples of each population have been collected regularly and more than 500.000 generations of E.coli have been observed to have passed. Lenski's research has demonstrated that mutations can alter the rate of change and the rate at which a population reproduces. It also demonstrates that evolution takes time, something that is hard for some to accept. Another example of microevolution is how mosquito genes that confer resistance to pesticides appear more frequently in areas where insecticides are used. This is due to the fact that the use of pesticides creates a selective pressure that favors individuals with resistant genotypes. The rapidity of evolution has led to an increasing awareness of its significance particularly in a world shaped largely by human activity. This includes the effects of climate change, pollution and habitat loss that hinders many species from adapting. Understanding evolution will aid you in making better decisions about the future of the planet and its inhabitants.