The Academy's Evolution Site
Biology is a key concept in biology. The Academies are committed to helping those who are interested in science to learn about the theory of evolution and how it is incorporated throughout all fields 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 unity in many cultures. It has many practical applications as well, including providing a framework to understand the history of species and how they react to changing environmental conditions.
Early attempts to describe 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 DNA fragments have significantly increased the diversity of a tree of Life2. These trees are largely composed by eukaryotes and the diversity of bacterial species is greatly underrepresented3,4.
Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the need for
에볼루션게이밍 direct observation and experimentation. Trees can be constructed using molecular techniques such as the small subunit ribosomal gene.
Despite the dramatic expansion of the Tree of Life through genome sequencing, much biodiversity still is waiting to be discovered. This is particularly the case for microorganisms which are difficult to cultivate, and which are usually only found in a single specimen5. Recent analysis of all genomes produced a rough draft of the Tree of Life. This includes a large number of archaea, bacteria, and other organisms that have not yet been isolated, or the diversity of which is not fully understood6.
The expanded Tree of Life can be used to determine the diversity of a specific region and determine if particular habitats need special protection. This information can be used in many ways, including finding new drugs, battling diseases and improving the quality of crops. This information is also useful for conservation efforts. It can aid biologists in identifying areas most likely to be home to species that are cryptic, which could have vital metabolic functions, and could be susceptible to the effects of human activity. While funds to protect biodiversity are important, the best method to preserve the world's biodiversity is to equip 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 connections between groups of organisms. Scientists can construct a phylogenetic diagram that illustrates the evolutionary relationship of taxonomic categories using molecular information and morphological similarities or differences. The concept of phylogeny is fundamental to understanding biodiversity, evolution and genetics.
A basic phylogenetic tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that have evolved from common ancestral. These shared traits may be homologous, or analogous. Homologous traits share their evolutionary roots and analogous traits appear similar but do not have the same ancestors. Scientists put similar traits into a grouping known as a clade. For instance, all the organisms that make up a clade have the characteristic of having amniotic egg and evolved from a common ancestor which had eggs. The clades are then linked to create a phylogenetic tree to determine which organisms have the closest relationship.
Scientists use molecular DNA or RNA data to create a phylogenetic chart which is more precise and detailed. 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 the same ancestor and estimate their evolutionary age.
The phylogenetic relationships of a species can be affected by a variety of factors, including phenotypicplasticity. This is a type of behavior that changes in response to particular environmental conditions. This can cause a characteristic to appear more similar to a species than to another,
에볼루션게이밍 obscuring the phylogenetic signals. This problem can be addressed by using cladistics. This is a method that incorporates an amalgamation of homologous and analogous features in the tree.
Furthermore, phylogenetics may help predict the time and pace of speciation. This information will assist conservation biologists in deciding which species to safeguard from extinction. In the end,
에볼루션 바카라 무료 코리아 (
Https://skinner-Cox.technetbloggers.De/) it is the conservation of phylogenetic diversity that will lead to an ecosystem that is balanced and complete.
Evolutionary Theory
The main idea behind evolution is that organisms alter over time because of their interactions with their environment. Several theories of evolutionary change have been proposed by a wide range of scientists, including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve gradually according to its requirements,
에볼루션 바카라사이트 the Swedish botanist Carolus Linnaeus (1707-1778) who conceived modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits cause changes that could be passed on to offspring.
In the 1930s and 1940s, ideas from various fields, including genetics, natural selection, and particulate inheritance - came together to form the current evolutionary theory, which defines how evolution happens through the variation of genes within a population and how those variations change over time due to natural selection. This model, which includes genetic drift, mutations in gene flow, and sexual selection, can be mathematically described.
Recent discoveries in the field of evolutionary developmental biology have demonstrated that variation can be introduced into a species by genetic drift, mutation, and reshuffling of genes during sexual reproduction, and also through the movement of populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time) can result in evolution that is defined as change in the genome of the species over time and the change in phenotype as time passes (the expression of the genotype in an individual).
Students can better understand the concept of phylogeny through incorporating evolutionary thinking throughout all areas of biology. In a recent study conducted by Grunspan et al. It was demonstrated that teaching students about the evidence for
에볼루션 룰렛 evolution increased their understanding of evolution in the course of a college biology. For
에볼루션게이밍 more information on how to teach about evolution, see The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have studied evolution through looking back in the past, analyzing fossils and comparing species. They also study living organisms. Evolution isn't a flims event, but an ongoing process. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals alter their behavior as a result of a changing environment. The resulting changes are often easy to see.
It wasn't until late 1980s when biologists began to realize that natural selection was also in action.