The Academy's Evolution Site
Biology is a key concept in biology. The Academies have been for a long time involved in helping those interested in science comprehend the concept of evolution and how it influences all areas of scientific research.
This site offers a variety of sources for students, teachers and general readers of evolution. It also includes important 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 spiritual traditions and cultures as symbolizing unity and love. 에볼루션 무료 바카라 has numerous practical applications as well, including providing a framework to understand the history of species, and how they respond to changes in environmental conditions.
The first attempts to depict the world of biology were built on categorizing organisms based on their metabolic and physical characteristics. These methods, which rely on sampling of different parts of living organisms, or small fragments of their DNA greatly increased the variety of organisms that could be represented in the tree of life2. However the trees are mostly composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4.
By avoiding the necessity for direct observation and experimentation, genetic techniques have enabled us to represent the Tree of Life in a much more accurate way. In particular, molecular methods enable us to create trees using sequenced markers, such as the small subunit ribosomal RNA gene.
무료에볼루션 of Life has been greatly expanded thanks to genome sequencing. However, there is still much biodiversity to be discovered. This is particularly true for microorganisms, which are difficult to cultivate and are typically only found in a single specimen5. A recent analysis of all genomes known to date has produced a rough draft version of the Tree of Life, including numerous bacteria and archaea that are not isolated and which are not well understood.
The expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if specific habitats need special protection. The information can be used in a variety of ways, from identifying new medicines to combating disease to enhancing the quality of the quality of crops. It is also useful to conservation efforts. It can aid biologists in identifying areas that are likely to be home to cryptic species, which may have important metabolic functions, and could be susceptible to human-induced change. While funds to protect biodiversity are important, the most effective way to conserve the world's biodiversity is to empower the people of developing nations with the information they require to act locally and promote conservation.
Phylogeny
A phylogeny is also known as an evolutionary tree, illustrates the relationships between various groups of organisms. Scientists can construct a phylogenetic chart that shows the evolution of taxonomic categories using molecular information and morphological differences or similarities. Phylogeny is crucial in understanding biodiversity, evolution and genetics.
A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms that share similar traits that have evolved from common ancestors. These shared traits are either homologous or analogous. Homologous traits are similar in their underlying evolutionary path and analogous traits appear like they do, but don't have the same origins. Scientists arrange similar traits into a grouping referred to as a clade. For example, all of the species in a clade share the trait of having amniotic eggs and evolved from a common ancestor who had these eggs. The clades are then linked to form a phylogenetic branch to identify organisms that have the closest connection to each other.
Scientists use DNA or RNA molecular data to create a phylogenetic chart that is more accurate and precise. This information is more precise than morphological information and provides evidence of the evolution background of an organism or group. Researchers can utilize Molecular Data to determine the evolutionary age of organisms and identify how many species have the same ancestor.
The phylogenetic relationships between organisms can be affected by a variety of factors, including phenotypic plasticity a type of behavior that changes in response to unique environmental conditions. This can cause a trait to appear more similar to one species than to the other and obscure the phylogenetic signals. This issue can be cured by using cladistics, which is a an amalgamation of analogous and homologous features in the tree.
In addition, phylogenetics helps determine the duration and speed at which speciation takes place. This information can aid conservation biologists to make decisions about which species they should protect from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will lead to a complete and balanced ecosystem.
Evolutionary Theory
The central theme of evolution is that organisms acquire various characteristics over time due to their interactions with their environments. Many scientists have proposed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could evolve according to its own requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical system of taxonomy, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of certain traits can result in changes that are passed on to the
In the 1930s and 1940s, concepts from various areas, including genetics, natural selection and particulate inheritance, merged to form a contemporary evolutionary theory. This describes how evolution happens through the variation of genes in a population and how these variations alter over time due to natural selection. 에볼루션사이트 , which encompasses genetic drift, mutations, gene flow and sexual selection is mathematically described mathematically.
Recent discoveries in evolutionary developmental biology have demonstrated the ways in which variation can be introduced to a species by genetic drift, mutations or reshuffling of genes in sexual reproduction, and even migration 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, which is defined by changes in the genome of the species over time and also by changes in phenotype over time (the expression of that genotype in the individual).
Incorporating evolutionary thinking into all aspects of biology education can increase students' understanding of phylogeny as well as evolution. In a recent study conducted by Grunspan et al. It was demonstrated that teaching students about the evidence for evolution boosted their understanding of evolution during an undergraduate biology course. For more details on how to teach about 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
Scientists have traditionally studied evolution by looking in the past, studying fossils, and comparing species. They also observe living organisms. Evolution isn't a flims event; it is a process that continues today. Bacteria evolve and resist antibiotics, viruses evolve and elude new medications and animals alter their behavior to a changing planet. The changes that result are often visible.
However, it wasn't until late 1980s that biologists realized that natural selection could be seen in action, as well. The key is that various traits have different rates of survival and reproduction (differential fitness) and are passed from one generation to the next.
In the past, if an allele - the genetic sequence that determines color - was found in a group of organisms that interbred, it could become more prevalent than any other allele. Over time, this would mean that the number of moths that have black pigmentation in a group may 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, 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 were taken frequently and more than 50,000 generations of E.coli have been observed to have passed.
Lenski's work has shown that mutations can alter the rate at which change occurs and the rate at which a population reproduces. It also shows that evolution takes time, a fact that is hard for some to accept.
Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides are used. This is due to the fact that the use of pesticides creates a selective pressure that favors people with resistant genotypes.
The speed at which evolution takes place has led to a growing recognition of its importance in a world shaped by human activity, including climate change, pollution, and the loss of habitats that hinder many species from adapting. Understanding evolution can assist you in making better choices about the future of the planet and its inhabitants.