15 Amazing Facts About Evolution Site
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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 who are interested in science learn about the theory of evolution and how it can be applied across all areas of scientific research.
This site offers a variety of resources for students, teachers as well as general readers about evolution. It has important video clips from NOVA and WGBH-produced science programs on DVD.
Tree of Life
The Tree of Life is an ancient symbol of the interconnectedness of life. It is seen in a variety of spiritual traditions and cultures as an emblem of unity and love. It also has practical applications, such as providing a framework to understand the history of species and how they respond to changing environmental conditions.
Early attempts to represent the world of biology were built on categorizing organisms based on their metabolic and physical characteristics. These methods rely on the collection of various parts of organisms or 무료에볼루션 (delphi.larsbo.org) short fragments of DNA have greatly increased the diversity of a Tree of Life2. These trees are largely composed by eukaryotes, and bacteria are largely underrepresented3,4.
Genetic techniques have significantly expanded our ability to visualize the Tree of Life by circumventing the need for direct observation and experimentation. We can create trees using molecular techniques such as the small subunit ribosomal gene.
Despite the dramatic growth of the Tree of Life through genome sequencing, much biodiversity still awaits discovery. This is especially true for 바카라 무료 에볼루션 (www.Nlvbang.Com) microorganisms that are difficult to cultivate, and are usually present in a single sample5. A recent analysis of all genomes produced a rough draft of a Tree of Life. This includes a variety of archaea, bacteria and other organisms that have not yet been isolated, or the diversity of which is not well understood6.
This expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if particular habitats need special protection. This information can be utilized in a variety of ways, from identifying the most effective treatments to fight disease to enhancing the quality of crops. The information is also incredibly valuable in conservation efforts. It can aid biologists in identifying areas that are likely to be home to cryptic species, which could have important metabolic functions and be vulnerable to human-induced change. While funding to protect biodiversity are important, the best method to preserve the biodiversity of the world is to equip the people of developing nations with the information they require to act locally and promote conservation.
Phylogeny
A phylogeny (also called an evolutionary tree) shows the relationships between species. Scientists can construct a phylogenetic chart that shows the evolution of taxonomic groups based on molecular data and morphological similarities or differences. Phylogeny is essential in understanding evolution, biodiversity 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 ancestral. These shared traits could be either analogous or homologous. Homologous characteristics are identical in terms of their evolutionary path. Analogous traits may look similar, but they do not have the same origins. Scientists group similar traits together into a grouping called a the clade. For example, all of the species in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor who had eggs. The clades are then linked to form a phylogenetic branch to determine which organisms have the closest relationship.
Scientists use DNA or RNA molecular data to build a phylogenetic chart that is more precise and detailed. This information is more precise and provides evidence of the evolution history of an organism. The use of molecular data lets researchers identify the number of species that share a common ancestor and to estimate their evolutionary age.
The phylogenetic relationships between organisms can be influenced by several factors including phenotypic plasticity, a kind of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more similar in one species than another, clouding the phylogenetic signal. This problem can be mitigated by using cladistics, which is a a combination of homologous and analogous traits in the tree.
Additionally, phylogenetics aids determine the duration and rate at which speciation takes place. This information can aid conservation biologists to decide the species they should safeguard from the threat of extinction. It is ultimately the preservation of phylogenetic diversity which will lead to an ecosystem that is complete and balanced.
Evolutionary Theory
The main idea behind evolution is that organisms alter over time because of their interactions with their environment. Many scientists have proposed theories of evolution, 무료 에볼루션 including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could evolve according to its own needs, 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 traits can lead to changes that can be passed on to future generations.
In the 1930s & 1940s, concepts from various areas, including natural selection, genetics & particulate inheritance, merged to form a contemporary synthesis of evolution theory. This explains how evolution is triggered by the variation in genes within the population, and 무료 에볼루션 how these variants change with time due to natural selection. This model, which is known as genetic drift mutation, gene flow and sexual selection, is a key element of modern evolutionary biology and can be mathematically described.
Recent developments in evolutionary developmental biology have shown how variations can be introduced to a species by mutations, genetic drift or reshuffling of genes in sexual reproduction and 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 result in evolution, which is defined by change in the genome of the species over time, and the change in phenotype over time (the expression of that genotype within the individual).
Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny as well as evolution. A recent study by Grunspan and colleagues, 무료 에볼루션 for example, showed that teaching about the evidence for evolution increased students' acceptance of evolution in a college biology course. For more information about how to teach evolution, see The Evolutionary Power of Biology in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.
Evolution in Action
Scientists have traditionally looked at evolution through the past, analyzing fossils and comparing species. They also study living organisms. Evolution is not a past event; it is an ongoing process that continues to be observed today. Bacteria evolve and resist antibiotics, viruses re-invent themselves and are able to evade new medications, and animals adapt their behavior to a changing planet. The results are usually evident.
However, it wasn't until late 1980s that biologists understood that natural selection could be observed in action as well. The key is that different characteristics result in different rates of survival and reproduction (differential fitness), and can be passed down from one generation to the next.
In the past, if a certain allele - the genetic sequence that determines colour - was found in a group of organisms that interbred, it might become more common than any other allele. In time, this 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.
Monitoring evolutionary changes in action is much easier when a species has a fast generation turnover like bacteria. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain. samples of each population are taken regularly, and over 500.000 generations have been observed.
Lenski's work has shown that mutations can alter the rate of change and the efficiency at which a population reproduces. It also demonstrates that evolution takes time, a fact that some find hard to accept.
Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides are used. This is because the use of pesticides creates a selective pressure that favors individuals who have resistant genotypes.
The rapid pace at which evolution takes place has led to an increasing appreciation of its importance in a world that is shaped by human activity--including climate change, pollution, and the loss of habitats that prevent the species from adapting. Understanding evolution can assist you in making better choices about the future of our planet and its inhabitants.
The concept of biological evolution is among the most important concepts in biology. The Academies are committed to helping those who are interested in science learn about the theory of evolution and how it can be applied across all areas of scientific research.
This site offers a variety of resources for students, teachers as well as general readers about evolution. It has important video clips from NOVA and WGBH-produced science programs on DVD.
Tree of Life
The Tree of Life is an ancient symbol of the interconnectedness of life. It is seen in a variety of spiritual traditions and cultures as an emblem of unity and love. It also has practical applications, such as providing a framework to understand the history of species and how they respond to changing environmental conditions.
Early attempts to represent the world of biology were built on categorizing organisms based on their metabolic and physical characteristics. These methods rely on the collection of various parts of organisms or 무료에볼루션 (delphi.larsbo.org) short fragments of DNA have greatly increased the diversity of a Tree of Life2. These trees are largely composed by eukaryotes, and bacteria are largely underrepresented3,4.
Genetic techniques have significantly expanded our ability to visualize the Tree of Life by circumventing the need for direct observation and experimentation. We can create trees using molecular techniques such as the small subunit ribosomal gene.
Despite the dramatic growth of the Tree of Life through genome sequencing, much biodiversity still awaits discovery. This is especially true for 바카라 무료 에볼루션 (www.Nlvbang.Com) microorganisms that are difficult to cultivate, and are usually present in a single sample5. A recent analysis of all genomes produced a rough draft of a Tree of Life. This includes a variety of archaea, bacteria and other organisms that have not yet been isolated, or the diversity of which is not well understood6.
This expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if particular habitats need special protection. This information can be utilized in a variety of ways, from identifying the most effective treatments to fight disease to enhancing the quality of crops. The information is also incredibly valuable in conservation efforts. It can aid biologists in identifying areas that are likely to be home to cryptic species, which could have important metabolic functions and be vulnerable to human-induced change. While funding to protect biodiversity are important, the best method to preserve the biodiversity of the world is to equip the people of developing nations with the information they require to act locally and promote conservation.
Phylogeny
A phylogeny (also called an evolutionary tree) shows the relationships between species. Scientists can construct a phylogenetic chart that shows the evolution of taxonomic groups based on molecular data and morphological similarities or differences. Phylogeny is essential in understanding evolution, biodiversity 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 ancestral. These shared traits could be either analogous or homologous. Homologous characteristics are identical in terms of their evolutionary path. Analogous traits may look similar, but they do not have the same origins. Scientists group similar traits together into a grouping called a the clade. For example, all of the species in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor who had eggs. The clades are then linked to form a phylogenetic branch to determine which organisms have the closest relationship.
Scientists use DNA or RNA molecular data to build a phylogenetic chart that is more precise and detailed. This information is more precise and provides evidence of the evolution history of an organism. The use of molecular data lets researchers identify the number of species that share a common ancestor and to estimate their evolutionary age.
The phylogenetic relationships between organisms can be influenced by several factors including phenotypic plasticity, a kind of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more similar in one species than another, clouding the phylogenetic signal. This problem can be mitigated by using cladistics, which is a a combination of homologous and analogous traits in the tree.
Additionally, phylogenetics aids determine the duration and rate at which speciation takes place. This information can aid conservation biologists to decide the species they should safeguard from the threat of extinction. It is ultimately the preservation of phylogenetic diversity which will lead to an ecosystem that is complete and balanced.
Evolutionary Theory
The main idea behind evolution is that organisms alter over time because of their interactions with their environment. Many scientists have proposed theories of evolution, 무료 에볼루션 including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could evolve according to its own needs, 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 traits can lead to changes that can be passed on to future generations.
In the 1930s & 1940s, concepts from various areas, including natural selection, genetics & particulate inheritance, merged to form a contemporary synthesis of evolution theory. This explains how evolution is triggered by the variation in genes within the population, and 무료 에볼루션 how these variants change with time due to natural selection. This model, which is known as genetic drift mutation, gene flow and sexual selection, is a key element of modern evolutionary biology and can be mathematically described.
Recent developments in evolutionary developmental biology have shown how variations can be introduced to a species by mutations, genetic drift or reshuffling of genes in sexual reproduction and 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 result in evolution, which is defined by change in the genome of the species over time, and the change in phenotype over time (the expression of that genotype within the individual).
Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny as well as evolution. A recent study by Grunspan and colleagues, 무료 에볼루션 for example, showed that teaching about the evidence for evolution increased students' acceptance of evolution in a college biology course. For more information about how to teach evolution, see The Evolutionary Power of Biology in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.
Evolution in Action
Scientists have traditionally looked at evolution through the past, analyzing fossils and comparing species. They also study living organisms. Evolution is not a past event; it is an ongoing process that continues to be observed today. Bacteria evolve and resist antibiotics, viruses re-invent themselves and are able to evade new medications, and animals adapt their behavior to a changing planet. The results are usually evident.
However, it wasn't until late 1980s that biologists understood that natural selection could be observed in action as well. The key is that different characteristics result in different rates of survival and reproduction (differential fitness), and can be passed down from one generation to the next.In the past, if a certain allele - the genetic sequence that determines colour - was found in a group of organisms that interbred, it might become more common than any other allele. In time, this 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.
Monitoring evolutionary changes in action is much easier when a species has a fast generation turnover like bacteria. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain. samples of each population are taken regularly, and over 500.000 generations have been observed.
Lenski's work has shown that mutations can alter the rate of change and the efficiency at which a population reproduces. It also demonstrates that evolution takes time, a fact that some find hard to accept.
Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides are used. This is because the use of pesticides creates a selective pressure that favors individuals who have resistant genotypes.
The rapid pace at which evolution takes place has led to an increasing appreciation of its importance in a world that is shaped by human activity--including climate change, pollution, and the loss of habitats that prevent the species from adapting. Understanding evolution can assist you in making better choices about the future of our planet and its inhabitants.
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