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

The Academy's Evolution Site

Biological evolution is a central concept in biology. The Academies have been active for a long time in helping people who are interested in science comprehend the concept of evolution and how it influences all areas of scientific research.

This site provides a range of resources for teachers, students and general readers of evolution. It contains key video clips from NOVA and 에볼루션 룰렛 바카라 무료 (italianculture.Net) 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 used in many religions and cultures as a symbol of unity and love. It also has many practical applications, like providing a framework for understanding the history of species and how they react to changes in environmental conditions.

The first attempts at depicting the world of biology focused on categorizing organisms into distinct categories which had been distinguished by physical and metabolic characteristics1. These methods, which relied on the sampling of various parts of living organisms, or short DNA fragments, greatly increased the variety of organisms that could be represented in a tree of life2. These trees are largely composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4.

In avoiding the necessity of direct experimentation and observation, genetic techniques have enabled us to depict the Tree of Life in a more precise way. Trees can be constructed using molecular methods like the small-subunit ribosomal 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 for microorganisms, which are difficult to cultivate and are often only present in a single specimen5. Recent analysis of all genomes produced an unfinished draft of the Tree of Life. This includes a variety of archaea, bacteria, and other organisms that have not yet been isolated or their diversity is not fully understood6.

The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, which can help to determine if certain habitats require protection. The information can be used in a variety of ways, from identifying new remedies to fight diseases to enhancing the quality of the quality of crops. It is also beneficial in conservation efforts. It helps biologists discover areas that are most likely to have species that are cryptic, which could have vital metabolic functions, and could be susceptible to changes caused by humans. While conservation funds 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 act locally and support conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, shows the connections between different groups of organisms. Scientists can construct a phylogenetic chart that shows the evolutionary relationship of taxonomic groups using molecular data and morphological similarities or differences. Phylogeny plays a crucial role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms with similar traits that evolved from common ancestral. These shared traits could be either analogous or 에볼루션 바카라사이트 (find out here) homologous. Homologous traits are similar in their evolutionary roots, 에볼루션바카라 (ceshi.xyhero.com) while analogous traits look similar but do not have the same origins. Scientists group similar traits into a grouping referred to as a the clade. For example, all of the organisms that make up a clade have the characteristic of having amniotic egg and evolved from a common ancestor which had eggs. The clades are then connected to form a phylogenetic branch to determine the organisms with the closest relationship.

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

The phylogenetic relationships of a species can be affected by a variety of factors such as the phenomenon of phenotypicplasticity. This is a kind of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar to a species than another which can obscure the phylogenetic signal. However, this issue can be solved through the use of methods such as cladistics which combine analogous and homologous features into the tree.

Additionally, phylogenetics aids determine the duration and rate at which speciation occurs. This information can aid conservation biologists to make decisions about which species to protect from the threat of extinction. It is ultimately the preservation of phylogenetic diversity that will lead to an ecologically balanced and complete ecosystem.

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, including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly according to its requirements, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived 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, theories from a variety of fields -- including genetics, natural selection and particulate inheritance -- came together to form the current evolutionary theory, which defines how evolution is triggered by the variation of genes within a population and how those variants change over time due to natural selection. This model, known as genetic drift mutation, 에볼루션 바카라사이트 gene flow, and sexual selection, is the foundation of current evolutionary biology, and can be mathematically described.

Recent developments in evolutionary developmental biology have shown how variations can be introduced to a species through mutations, genetic drift or reshuffling of genes in sexual reproduction and migration between populations. These processes, as well as other ones like the directional selection process and the erosion of genes (changes in the frequency of genotypes over time) can lead to evolution. Evolution is defined as changes in the genome over time, as well as changes in the phenotype (the expression of genotypes within individuals).

Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking into all aspects of biology. In a recent study conducted by Grunspan and colleagues. It was found that teaching students about the evidence for evolution increased their understanding of evolution in a college-level course in biology. To find out more about how to teach about evolution, please read The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution through studying fossils, comparing species and observing living organisms. But evolution isn't just something that happened in the past; it's an ongoing process, 에볼루션 카지노 taking place today. Viruses reinvent themselves to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior in the wake of a changing world. The changes that result are often easy to see.

It wasn't until late 1980s that biologists began realize that natural selection was also in action. The key is that different traits confer different rates of survival and reproduction (differential fitness), and can be transferred from one generation to the next.

In the past, if one particular allele - the genetic sequence that controls coloration - was present in a population of interbreeding organisms, it could quickly become more common than other alleles. In time, this could 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.

Monitoring evolutionary changes in action is much easier when a species has a rapid turnover of its generation, as with bacteria. Since 1988, Richard Lenski, a biologist, has been tracking twelve populations of E.coli that are descended from a single strain. The samples of each population have been taken frequently and more than 50,000 generations of E.coli have been observed to have passed.

Lenski's research has shown that a mutation can dramatically alter the rate at the rate at which a population reproduces, and consequently the rate at which it changes. 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 pesticide resistance are more prevalent in areas where insecticides have been used. Pesticides create a selective pressure which favors those who have resistant genotypes.

The speed of evolution taking place has led to an increasing awareness of its significance in a world shaped by human activity--including climate change, pollution and the loss of habitats that hinder many species from adapting. Understanding the evolution process will help you make better decisions about the future of our planet and its inhabitants.