• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

The Academy's Evolution Site

Biology is a key concept in biology. The Academies are involved in helping those who are interested in science comprehend the evolution theory and how it can be applied in all areas of scientific research.

This site provides a wide range of resources for students, teachers, and general readers on evolution. It contains important 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 appears in many religions and cultures as symbolizing unity and love. It also has important practical applications, such as providing a framework to understand the history of species and how they respond to changes in environmental conditions.

Early approaches to depicting the world of biology focused on separating organisms into distinct categories that had been distinguished by their physical and metabolic characteristics1. These methods, based on the sampling of different parts of living organisms or small fragments of their DNA, significantly increased the variety that could be represented in the tree of life2. These trees are largely composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4.

Genetic techniques have greatly expanded our ability to depict the Tree of Life by circumventing the requirement for direct observation and experimentation. In particular, molecular methods allow us to build trees by using sequenced markers such as the small subunit ribosomal gene.

The Tree of Life has been greatly expanded thanks to genome sequencing. However there is still a lot of biodiversity to be discovered. This is particularly true for microorganisms that are difficult to cultivate, 에볼루션 사이트 and are usually found in one sample5. A recent study of all genomes known to date has produced a rough draft version of the Tree of Life, including many archaea and 에볼루션 룰렛 게이밍 (Www.Mi-Zhenimsya.ru) bacteria that are not isolated and whose diversity is poorly understood6.

This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, helping to determine if certain habitats require special protection. The information can be used in a variety of ways, from identifying new treatments to fight disease to enhancing crop yields. The information is also beneficial to conservation efforts. It can help biologists identify areas most likely to have species that are cryptic, which could have important metabolic functions and are susceptible to changes caused by humans. While funds to safeguard biodiversity are vital, ultimately the best way to protect the world's biodiversity is for more people in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny (also called an evolutionary tree) shows the relationships between different organisms. Scientists can construct a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic categories using molecular information and morphological differences or similarities. Phylogeny is crucial in understanding the evolution of biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 Finds the connections between organisms that have similar characteristics and have evolved from a common ancestor. These shared traits may be homologous, or analogous. Homologous traits are identical in their evolutionary origins and analogous traits appear like they do, but don't have the identical origins. Scientists arrange similar traits into a grouping called a clade. For instance, all the species in a clade have the characteristic of having amniotic egg and evolved from a common ancestor which had these eggs. A phylogenetic tree can be constructed by connecting the clades to identify the organisms who are the closest to each other.

Scientists use DNA or RNA molecular information to build a phylogenetic chart that is more precise and detailed. This data is more precise than morphological data and provides evidence of the evolution background of an organism or group. Researchers can utilize Molecular Data to estimate the evolutionary age of living organisms and discover how many organisms share an ancestor common to all.

The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic flexibility, an aspect of behavior that changes in response to unique environmental conditions. This can cause a trait to appear more like a species another, obscuring the phylogenetic signal. However, this issue can be solved through the use of methods such as cladistics that combine homologous and analogous features into the tree.

Additionally, phylogenetics aids predict the duration and rate of speciation. This information can help conservation biologists make decisions about the species they should safeguard from extinction. In the end, 에볼루션바카라사이트 it's the conservation of phylogenetic diversity which will create an ecosystem that is balanced and complete.

Evolutionary Theory

The central theme in evolution is that organisms change over time as a result of their interactions with their environment. Many scientists have proposed theories of evolution, 에볼루션바카라사이트 including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would develop according to its own requirements, 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 non-use of traits can cause changes that are passed on to the

In the 1930s and 1940s, concepts from various fields, including genetics, natural selection, and particulate inheritance - came together to create the modern evolutionary theory synthesis, which defines how evolution is triggered by the variation of genes within a population and how these variants change in time due to natural selection. This model, known as genetic drift or mutation, gene flow and sexual selection, is the foundation of the current evolutionary biology and is mathematically described.

Recent discoveries in the field of evolutionary developmental biology have demonstrated that genetic variation can be introduced into a species through genetic drift, mutation, and reshuffling of genes in sexual reproduction, and also by migration between populations. These processes, along with others such as the directional selection process and the erosion of genes (changes to the frequency of genotypes over time) can lead to evolution. Evolution is defined by changes in the genome over time, as well as changes in the phenotype (the expression of genotypes in an individual).

Incorporating evolutionary thinking into all aspects of biology education can improve students' understanding of phylogeny as well as evolution. A recent study by Grunspan and colleagues, for 에볼루션 코리아카지노사이트 - site, instance revealed that teaching students about the evidence for evolution increased students' understanding of evolution in a college-level biology class. To learn more about 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 traditionally studied evolution through looking back in the past, analyzing fossils and comparing species. They also study living organisms. Evolution isn't a flims moment; it is an ongoing process. Viruses reinvent themselves to avoid new medications and bacteria mutate to resist antibiotics. Animals alter their behavior as a result of a changing environment. The results are often evident.

However, it wasn't until late 1980s that biologists understood that natural selection could be observed in action as well. The key is the fact that different traits can confer a different 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 determines coloration--appeared in a group of interbreeding organisms, it could quickly become more prevalent than the other alleles. Over time, that would mean the number of black moths in the population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to track evolution 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 are taken regularly, and over fifty thousand generations have been observed.

Lenski's work has shown that mutations can alter the rate at which change occurs and the rate of a population's reproduction. It also shows that evolution takes time, which is hard for some to accept.

Another example of microevolution is that mosquito genes that are resistant to pesticides appear more frequently in areas where insecticides are employed. Pesticides create a selective pressure which favors those who have resistant genotypes.

The rapidity of evolution has led to an increasing recognition of its importance especially in a planet which is largely shaped by human activities. This includes climate change, pollution, and habitat loss, which prevents many species from adapting. Understanding evolution will help you make better decisions about the future of the planet and its inhabitants.