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Buzzwords De-Buzzed: 10 Other Ways Of Saying Evolution Site
The Academy's Evolution Site

Biological evolution is a central 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 can be applied throughout all fields of scientific research.

This site provides a wide range of resources for teachers, students, and general readers on 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 a symbol of love and harmony in a variety of cultures. It also has practical uses, like providing a framework to understand the history of species and how they respond to changes in environmental conditions.

Early attempts to describe the world of biology were founded on categorizing organisms on their metabolic and physical characteristics. These methods, based on the sampling of various parts of living organisms or sequences of small fragments of their DNA, greatly increased the variety of organisms that could be represented in the tree of life2. However these trees are mainly made up of eukaryotes. Bacterial diversity remains vastly underrepresented3,4.

By avoiding the necessity for direct observation and experimentation genetic techniques have allowed us to represent the Tree of Life in a much more accurate way. Particularly, molecular techniques allow us to construct trees using sequenced markers like the small subunit of ribosomal RNA gene.

에볼루션 코리아 of Life has been significantly expanded by genome sequencing. However, there is still much diversity to be discovered. This is especially relevant to microorganisms that are difficult to cultivate and which are usually only present in a single sample5. A recent analysis of all genomes known to date has produced a rough draft version of the Tree of Life, including many archaea and bacteria that have not been isolated, and their diversity is not fully understood6.

This expanded Tree of Life can be used to determine the diversity of a specific area and determine if specific habitats need special protection. This information can be utilized in a variety of ways, from identifying the most effective remedies to fight diseases to improving crops. This information is also extremely beneficial to conservation efforts. It can aid biologists in identifying the areas most likely to contain cryptic species that could have important metabolic functions that may be at risk of anthropogenic changes. While funding to protect biodiversity are important, the most effective method to preserve the biodiversity of the world is to equip the people of developing nations with the knowledge they need to act locally and promote conservation.

Phylogeny

A phylogeny (also known as an evolutionary tree) depicts the relationships between species. Scientists can build a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic groups based on molecular data and morphological differences or similarities. The concept of phylogeny is fundamental to understanding biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms with similar traits and evolved from an ancestor that shared traits. These shared traits can be analogous or homologous. Homologous characteristics are identical in terms of their evolutionary journey. Analogous traits might appear similar but they don't have the same ancestry. Scientists organize similar traits into a grouping known as a the clade. For instance, all of the species in a clade share the trait of having amniotic eggs and evolved from a common ancestor which had eggs. A phylogenetic tree is built by connecting the clades to determine the organisms which are the closest to one another.

For a more detailed and accurate phylogenetic tree scientists use molecular data from DNA or RNA to determine the connections between organisms. This information is more precise than morphological information and gives evidence of the evolutionary background of an organism or group. Researchers can utilize Molecular Data to estimate the evolutionary age of living organisms and discover how many species have the same ancestor.

The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic flexibility, a type of behavior that alters in response to specific environmental conditions. This can cause a trait to appear more similar to one species than other species, which can obscure the phylogenetic signal. This problem can be mitigated by using cladistics, which is a the combination of analogous and homologous features in the tree.

Furthermore, phylogenetics may aid in predicting the duration and rate of speciation. This information can help conservation biologists make decisions about which species to protect from the threat of extinction. Ultimately, it is the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced.

Evolutionary Theory

The fundamental concept in evolution is that organisms change over time as a result of their interactions with their environment. A variety of theories about evolution have been developed by a wide range of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly in accordance with its requirements as well as the Swedish botanist Carolus Linnaeus (1707-1778) who designed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that could be passed on to offspring.

In the 1930s and 1940s, concepts from a variety of fields--including genetics, natural selection, and particulate inheritance--came together to form the modern evolutionary theory, which defines how evolution happens through the variation of genes within a population and how these variants change in time as a result of natural selection. This model, which incorporates mutations, genetic drift as well as gene flow and sexual selection can be mathematically described.

Recent advances in evolutionary developmental biology have demonstrated the ways in which variation can be introduced to a species by mutations, genetic drift or reshuffling of genes in sexual reproduction, and even migration between populations. These processes, in conjunction with other ones like directionally-selected selection and erosion of genes (changes to the frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes in individuals).

Incorporating evolutionary thinking into all aspects of biology education can improve student understanding of the concepts of phylogeny as well as evolution. A recent study by Grunspan and colleagues, for instance revealed that teaching students about the evidence supporting evolution increased students' understanding of evolution in a college biology class. For more information on how to teach about evolution read The Evolutionary Power of Biology in all Areas of Biology or Thinking Evolutionarily: a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Scientists have traditionally looked at evolution through the past, studying fossils, and comparing species. 에볼루션 바카라 무료체험 study living organisms. Evolution is not a distant moment; it is a process that continues today. Bacteria evolve and resist antibiotics, viruses evolve and escape new drugs, and animals adapt their behavior in response to the changing environment. The results are often apparent.

It wasn't until the late 1980s that biologists began realize that natural selection was at work. The key to this is that different traits result in a different rate of survival and reproduction, and can be passed on from one generation to the next.

In the past, if one allele - the genetic sequence that determines color - was found in a group of organisms that interbred, it could be more prevalent than any other allele. Over time, this would mean that the number of moths sporting black pigmentation in a population may increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to see evolutionary change when an organism, like bacteria, has a rapid generation turnover. 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 on a regular basis, and over 500.000 generations have been observed.

Lenski's work has shown that mutations can alter the rate at which change occurs and the efficiency at which a population reproduces. It also demonstrates that evolution takes time, a fact that some people find hard to accept.


Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in populations that have used insecticides. This is because pesticides cause an enticement that favors those with resistant genotypes.

The rapidity of evolution has led to a growing awareness of its significance particularly in a world that is largely shaped by human activity. This includes the effects of climate change, pollution and habitat loss, which prevents many species from adapting. Understanding evolution can help us make better choices about the future of our planet, as well as the lives of its inhabitants.

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