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

The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies are involved in helping those who are interested in science understand evolution theory and how it is permeated in all areas of scientific research.

This site provides a wide range of tools for teachers, students, and general readers on evolution. It has the most important video clips from NOVA and WGBH's science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is an emblem of love and unity in many cultures. It also has practical uses, like providing a framework to understand the evolution of species and how they react to changing environmental conditions.

Early approaches to depicting the biological world focused on categorizing organisms into distinct categories that were distinguished by physical and metabolic characteristics1. These methods, which depend on the collection of various parts of organisms, or fragments of DNA have significantly increased the diversity of a tree of Life2. The trees are mostly composed by eukaryotes and bacteria are largely underrepresented3,4.

Genetic techniques have significantly expanded our ability to depict the Tree of Life by circumventing the requirement for 에볼루션 바카라 무료게이밍 (theindietube.com) direct observation and experimentation. In particular, molecular methods enable us to create trees using sequenced markers such as the small subunit ribosomal RNA gene.

The Tree of Life has been dramatically expanded through genome sequencing. However there is still a lot of diversity to be discovered. This is particularly true of microorganisms that are difficult to cultivate and are usually only present in a single sample5. Recent analysis of all genomes has produced an initial draft of a Tree of Life. This includes a wide range of bacteria, archaea and other organisms that haven't yet been isolated or whose diversity has not been fully understood6.

The expanded Tree of Life can be used to evaluate the biodiversity of a specific area and determine if specific habitats require special protection. The information can be used in a range of ways, from identifying new medicines to combating disease to enhancing crop yields. The information is also useful in conservation efforts. It helps biologists discover areas most likely to have cryptic species, which could have important metabolic functions and be vulnerable to changes caused by humans. While funds to protect biodiversity are essential but the most effective way to protect the world's biodiversity is for more people in developing countries to be empowered with the necessary knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, reveals the relationships between groups of organisms. Scientists can create an phylogenetic chart which shows the evolution of taxonomic groups based on molecular data and morphological differences or similarities. Phylogeny is crucial in understanding biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that evolved from common ancestors. These shared traits may be analogous or homologous. Homologous traits are similar in terms of their evolutionary path. Analogous traits could appear similar but they don't have the same origins. Scientists combine similar traits into a grouping known as a clade. Every organism in a group share a characteristic, for 에볼루션 바카라 체험 example, amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree can be constructed by connecting the clades to identify the species that are most closely related to one another.

Scientists make use of DNA or RNA molecular data to create a phylogenetic chart which is more precise and precise. This data is more precise than morphological information and gives evidence of the evolutionary history of an organism or group. The analysis of molecular data can help researchers determine the number of species who share an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships of a species can be affected by a number of factors that include the phenomenon of phenotypicplasticity. This is a kind of behavior that alters due to unique environmental conditions. This can cause a particular trait to appear more similar to one species than other species, which can obscure the phylogenetic signal. However, this issue can be solved through the use of techniques such as cladistics that incorporate a combination of homologous and analogous features into the tree.

Additionally, phylogenetics can help determine the duration and rate at which speciation occurs. This information can aid conservation biologists to make decisions about which species to protect from extinction. Ultimately, it is the preservation of phylogenetic diversity which will create a complete and balanced ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms alter over time because of their interactions with their environment. Many scientists have come up with theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could develop according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), 에볼루션사이트 who believed that the use or non-use of certain traits can result in changes that can be passed on to future generations.

In the 1930s and 1940s, theories from various areas, including natural selection, genetics & particulate inheritance, were brought together to form a modern synthesis of evolution theory. This defines how evolution happens through the variation of genes in a population and how these variants change with time due to natural selection. This model, which includes mutations, genetic drift as well as gene flow and sexual selection can be mathematically described mathematically.

Recent discoveries in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species by mutation, genetic drift, and reshuffling of genes in sexual reproduction, as well as through migration between populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of the genotype over time) can result in evolution, which is defined by changes in the genome of the species over time, and also the change in phenotype as time passes (the expression of the genotype in the individual).

Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny as well as evolution. In a recent study by Grunspan and colleagues., it was shown that teaching students about the evidence for evolution boosted their acceptance of evolution during a college-level course in biology. For more details about how to teach evolution, see The Evolutionary Potency in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution by looking back, studying fossils, comparing species and observing living organisms. However, evolution isn't something that happened in the past, it's an ongoing process that is taking place right now. Viruses evolve to stay away from new drugs and bacteria evolve to resist antibiotics. Animals alter their behavior because of a changing world. The changes that result are often apparent.

It wasn't until late 1980s when biologists began to realize that natural selection was in action. The reason is that different traits have different rates of survival and reproduction (differential fitness) and are transferred from one generation to the next.

In the past, if one allele - the genetic sequence that determines colour - was present in a population of organisms that interbred, it could be more prevalent than any other allele. In time, this could mean that the number of moths sporting black pigmentation 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 evolutionary change when a species, such as bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, 에볼루션사이트 has tracked twelve populations of E.coli that descend from a single strain. The samples of each population have been collected regularly and more than 50,000 generations of E.coli have passed.

Lenski's research has revealed that mutations can alter the rate at which change occurs and the rate at which a population reproduces. It also shows that evolution takes time, a fact that is difficult for some to accept.

Microevolution can be observed in the fact that mosquito genes for resistance to pesticides are more common in populations where insecticides are used. This is due to pesticides causing an exclusive pressure that favors those with resistant genotypes.

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