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

The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been for a long time involved in helping those interested in science comprehend the concept of evolution and how it permeates all areas of scientific exploration.

This site offers a variety of sources for students, teachers, and general readers on evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life, 에볼루션 무료 바카라 an ancient symbol, symbolizes the interconnectedness of all life. It is used in many religions and cultures as a symbol of unity and love. It has numerous practical applications as well, including providing a framework for understanding the history of species, and how they respond to changing environmental conditions.

The first attempts at depicting the biological world focused on separating organisms into distinct categories which were distinguished by physical and metabolic characteristics1. These methods depend on the sampling of different parts of organisms or DNA fragments, have significantly increased the diversity of a tree of Life2. These trees are mostly populated by eukaryotes and bacteria are largely underrepresented3,4.

Genetic techniques have significantly expanded our ability to visualize the Tree of Life by circumventing the need for direct observation and experimentation. Trees can be constructed by using molecular methods, such as the small-subunit ribosomal gene.

Despite the rapid expansion of the Tree of Life through genome sequencing, a large amount of biodiversity remains to be discovered. This is particularly true for microorganisms, which can be difficult to cultivate and are typically only present in a single specimen5. A recent analysis of all genomes produced an unfinished draft of a Tree of Life. This includes a variety of archaea, bacteria and other organisms that have not yet been isolated, or whose diversity has not been thoroughly understood6.

The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, which can help to determine whether specific habitats require protection. This information can be used in a variety of ways, including finding new drugs, battling diseases and improving crops. This information is also extremely beneficial to conservation efforts. It can aid biologists in identifying those areas that are most likely contain cryptic species with potentially significant metabolic functions that could be at risk of anthropogenic changes. While funds to protect biodiversity are important, the best method to protect the world's biodiversity is to empower the people of developing nations with the information they require to take action locally and encourage conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the relationships between different groups of organisms. By using molecular information, morphological similarities and differences or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree that illustrates the evolutionary relationship between taxonomic groups. 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 ) identifies the relationships between organisms that share similar traits that have evolved from common ancestral. These shared traits could be analogous, or homologous. Homologous traits are similar in their evolutionary roots while analogous traits appear like they do, but don't have the same origins. Scientists organize similar traits into a grouping called a clade. All organisms in a group have a common trait, such as amniotic egg production. They all evolved from an ancestor that had these eggs. The clades are then connected to create a phylogenetic tree to identify organisms that have the closest relationship to.

For a more detailed and precise phylogenetic tree scientists use molecular data from DNA or RNA to identify the relationships among organisms. This information is more precise and gives evidence of the evolution of an organism. The analysis of molecular data can help researchers identify the number of organisms that 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 type of behavior that alters in response to unique environmental conditions. This can make a trait appear more similar to one species than to the other and obscure the phylogenetic signals. However, this issue can be reduced by the use of techniques like cladistics, which incorporate a combination of analogous and homologous features into the tree.

In addition, phylogenetics helps determine the duration and rate at which speciation takes place. This information can help conservation biologists make decisions about which species to protect from extinction. In the end, it's the conservation of phylogenetic variety that will lead to an ecosystem that is complete and balanced.

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, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that a living thing would evolve according to its own 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 use or non-use of certain traits can result in changes that are passed on to the

In the 1930s & 1940s, ideas from different areas, 에볼루션 사이트 including genetics, natural selection, and particulate inheritance, came together to form a contemporary synthesis of evolution theory. This explains how evolution is triggered by the variation of genes in the population, and how these variants change with time due to natural selection. This model, which includes genetic drift, mutations in gene flow, and sexual selection can be mathematically described.

Recent developments in the field of evolutionary developmental biology have revealed how variations can be introduced to a species via mutations, genetic drift or reshuffling of genes in sexual reproduction and migration between populations. These processes, in conjunction with others, 에볼루션 무료 바카라 such as directional selection and gene erosion (changes in the frequency of genotypes over time) can lead to evolution. Evolution is defined as changes in the genome over time and changes in the phenotype (the expression of genotypes in an individual).

Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny and evolution. In a study by Grunspan and co., 에볼루션바카라사이트 it was shown that teaching students about the evidence for evolution boosted their acceptance of evolution during an undergraduate biology course. For more information on how to teach about evolution read The Evolutionary Potency in all Areas of Biology or Thinking Evolutionarily as a Framework for Integrating 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 is not a distant event, but an ongoing process that continues to be observed today. The virus reinvents itself to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior in the wake of a changing environment. The results are often apparent.

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

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

It is easier to observe evolution when the species, like bacteria, has a rapid generation turnover. Since 1988, 에볼루션사이트 Richard Lenski, a biologist, has been tracking twelve populations of E.coli that descend from a single strain. Samples from each population have been taken regularly and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's work has shown that mutations can alter the rate at which change occurs and the effectiveness of a population's reproduction. It also shows that evolution is slow-moving, a fact that some find difficult to accept.

Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in populations where insecticides are used. This is because the use of pesticides causes a selective pressure that favors those with resistant genotypes.

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