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The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been active for a long time in helping people who are interested in science understand the theory of evolution and 바카라 에볼루션 how it permeates all areas of scientific research.

This site provides a wide range of tools for students, teachers and general readers of evolution. It includes key video clip from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol of the interconnectedness of all life. It is a symbol of love and unity across many cultures. It can be used in many practical ways as well, including providing a framework for understanding the history of species and how they react to changing environmental conditions.

Early attempts to represent the world of biology were based on categorizing organisms based on their physical and metabolic characteristics. These methods, which depend on the sampling of different parts of organisms or short DNA fragments have significantly increased the diversity of a Tree of Life2. These trees are largely composed of eukaryotes, while the diversity of bacterial species is greatly underrepresented3,4.

In avoiding the necessity of direct observation and experimentation genetic techniques have made it possible to represent the Tree of Life in a more precise manner. We can create trees using molecular methods such as the small subunit ribosomal gene.

The Tree of Life has been dramatically expanded through genome sequencing. However there is a lot of biodiversity to be discovered. This is especially true of microorganisms, which are difficult to cultivate and are often only represented in a single specimen5. A recent study of all known genomes has produced a rough draft version of the Tree of Life, including a large number of archaea and bacteria that are not isolated and which are not well understood.

This expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine whether specific habitats require special protection. The information can be used in a range of ways, from identifying new medicines to combating disease to improving crop yields. This information is also useful for conservation efforts. It can help biologists identify areas that are most likely to be home to cryptic species, which could perform important metabolic functions and are susceptible to human-induced change. While funding to protect biodiversity are essential, the best method to preserve the world's biodiversity is to equip more people in developing nations with the knowledge they need to act locally and support conservation.

Phylogeny

A phylogeny, also known as an evolutionary tree, reveals the relationships between different groups of organisms. Using molecular data similarities and differences in morphology, or ontogeny (the course of development of an organism), scientists can build a phylogenetic tree that illustrates the evolutionary relationships between taxonomic categories. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and have evolved from a common ancestor. These shared traits are either analogous or 에볼루션 게이밍 homologous. Homologous traits share their underlying evolutionary path while analogous traits appear similar but do not have the identical origins. Scientists put similar traits into a grouping referred to as a clade. Every organism in a group share a characteristic, for example, amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree is then constructed by connecting the clades to identify the species that are most closely related to each other.

For a more precise and accurate phylogenetic tree, scientists make use of molecular data from DNA or RNA to establish the connections between organisms. This data is more precise than morphological information and provides evidence of the evolution background of an organism or group. Molecular data allows researchers to determine the number of organisms that have the same ancestor and estimate their evolutionary age.

Phylogenetic relationships can be affected by a number of factors such as phenotypicplasticity. This is a type of behavior 에볼루션 코리아 that changes due to specific environmental conditions. This can cause a trait to appear more resembling to one species than to another and obscure the phylogenetic signals. This problem can be mitigated by using cladistics. This is a method that incorporates a combination of analogous and homologous features in the tree.

Additionally, phylogenetics can help predict the time and pace of speciation. This information can aid conservation biologists in deciding which species to protect from the threat of extinction. In the end, it is the conservation of phylogenetic variety which will create an ecosystem that is balanced and complete.

Evolutionary Theory

The main idea behind evolution is that organisms change over time due to their interactions with their environment. Many scientists have come up with theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that a living thing would develop according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the usage or non-use of traits can cause changes that can be passed on to future generations.

In the 1930s and 1940s, ideas from a variety of fields--including genetics, natural selection, and particulate inheritance - came together to create the modern evolutionary theory synthesis which explains how evolution happens through the variations of genes within a population and how those variations change over time as a result of natural selection. This model, called genetic drift or mutation, gene flow and sexual selection, is the foundation of modern evolutionary biology and is mathematically described.

Recent developments in evolutionary developmental biology have demonstrated how variations can be introduced to a species through genetic drift, mutations or reshuffling of genes in sexual reproduction and the movement between populations. These processes, along with 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 as time passes (the expression of the genotype within the individual).

Students can better understand the concept of phylogeny by using evolutionary thinking throughout all areas of biology. A recent study by Grunspan and colleagues, for instance demonstrated that teaching about the evidence supporting evolution increased students' understanding of evolution in a college-level biology class. For more information on how to teach about evolution, please read The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing the Concept of Evolution into Life Sciences Education.

Evolution in Action

Scientists have looked at evolution through the past, studying fossils, and comparing species. They also study living organisms. But evolution isn't a thing that happened in the past, 에볼루션 무료체험 it's an ongoing process that is happening today. The virus reinvents itself to avoid new drugs and bacteria evolve to resist antibiotics. Animals adapt their behavior 에볼루션 게이밍 (xxh5gamebbs.uwan.com) as a result of the changing environment. The changes that result are often apparent.

But it wasn't until the late-1980s that biologists realized that natural selection can be observed in action as well. The key is the fact that different traits result in an individual rate of survival as well as reproduction, and may be passed on from one generation to another.

In the past when one particular allele--the genetic sequence that controls coloration - was present in a population of interbreeding organisms, it could rapidly become more common than other alleles. In time, this could mean that the number of moths that have black pigmentation in a group could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

Observing evolutionary change in action is much easier when a species has a rapid generation turnover like bacteria. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from one strain. Samples of each population have been taken regularly and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has shown that a mutation can dramatically alter the speed at which a population reproduces and, consequently the rate at which it evolves. It also proves that evolution takes time--a fact that some people find difficult to accept.

Another example of microevolution is that mosquito genes that confer resistance to pesticides show up more often in areas in which insecticides are utilized. This is because pesticides cause an enticement that favors those who have resistant genotypes.

The rapidity of evolution has led to an increasing appreciation of its importance particularly in a world shaped largely by human activity. This includes pollution, climate change, and habitat loss, which prevents many species from adapting. Understanding the evolution process can assist you in making better choices about the future of the planet and its inhabitants.