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

The Academy's Evolution Site

The concept of biological evolution is a fundamental concept in biology. The Academies are committed to helping those interested in science to understand evolution theory and how it can be applied in all areas of scientific research.

This site provides teachers, students and 에볼루션 코리아 general readers with a wide range of learning resources about evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is seen in a variety of religions and cultures as symbolizing unity and love. It has numerous practical applications as well, such as providing a framework for understanding the history of species, and how they react to changing environmental conditions.

The first attempts at depicting the biological world focused on categorizing organisms into distinct categories that had been identified by their physical and metabolic characteristics1. These methods, which rely on the sampling of various parts of living organisms or on sequences of short DNA fragments, significantly increased the variety that could be represented in the tree of life2. However these trees are mainly made up of eukaryotes. Bacterial diversity is still largely unrepresented3,4.

Genetic techniques have significantly expanded our ability to represent the Tree of Life by circumventing the requirement for direct observation and experimentation. We can create trees by using molecular methods, such as the small-subunit ribosomal gene.

The Tree of Life has been greatly expanded thanks to genome sequencing. However, there is still much biodiversity to be discovered. This is particularly relevant to microorganisms that are difficult to cultivate, and are typically found in one sample5. A recent analysis of all genomes produced an unfinished draft of the Tree of Life. This includes a wide range of archaea, bacteria and other organisms that have not yet been isolated or whose diversity has not been fully understood6.

The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, assisting to determine if specific habitats require protection. The information can be used in a variety of ways, from identifying the most effective medicines to combating disease to enhancing the quality of crops. This information is also extremely beneficial in conservation efforts. It can aid biologists in identifying areas most likely to be home to cryptic species, which may perform important metabolic functions and be vulnerable to the effects of human activity. Although funding to protect biodiversity are crucial however, the most effective method to ensure the preservation of biodiversity around the world is for more people in developing countries to be equipped with the knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny, also known as an evolutionary tree, shows the connections between different groups of organisms. Scientists can build a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic groups based on molecular data and morphological differences or similarities. Phylogeny plays a crucial role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that have evolved from common ancestors. These shared traits are either homologous or 에볼루션 게이밍 analogous. Homologous characteristics are identical in terms of their evolutionary path. Analogous traits may look similar however they do not have the same origins. Scientists group similar traits together into a grouping called a clade. For instance, all the organisms that make up a clade have the characteristic of having amniotic eggs and evolved from a common ancestor that had these eggs. A phylogenetic tree can be built by connecting the clades to identify the organisms that are most closely related to each other.

Scientists make use of DNA or RNA molecular information to construct a phylogenetic graph that is more accurate and detailed. This information is more precise and provides evidence of the evolution history of an organism. Researchers can use Molecular Data to determine the evolutionary age of organisms and determine how many organisms have the same ancestor.

The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic flexibility, a kind of behavior that changes in response to unique environmental conditions. This can cause a trait to appear more similar to a species than another which can obscure the phylogenetic signal. This issue can be cured by using cladistics, 에볼루션 which is a an amalgamation of homologous and analogous traits in the tree.

Furthermore, phylogenetics may aid in predicting the time and pace of speciation. This information will assist conservation biologists in deciding which species to safeguard from the threat of extinction. It is ultimately the preservation of phylogenetic diversity that will create an ecosystem that is complete and balanced.

Evolutionary Theory

The fundamental concept in evolution is that organisms alter over time because of 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 an organism could develop according to its own needs as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern taxonomy system that is hierarchical as well as Jean-Baptiste Lamarck (1844-1829), who believed that the use or absence of traits can lead to changes that are passed on to the

In the 1930s & 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance, were brought together to form a contemporary evolutionary 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, known as genetic drift or mutation, gene flow, and sexual selection, is a key element of modern evolutionary biology and can be mathematically described.

Recent developments in the field of evolutionary developmental biology have shown that variations can be introduced into a species through mutation, genetic drift, and reshuffling of genes in sexual reproduction, 에볼루션 코리아 as well as through the movement of populations. These processes, along with other ones like directionally-selected selection and erosion of genes (changes to 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 in an individual).

Students can better understand phylogeny by incorporating evolutionary thinking in all aspects of biology. A recent study conducted by Grunspan and colleagues, for instance demonstrated that teaching about the evidence for evolution helped students accept the concept of evolution in a college-level biology course. For more details on how to teach about evolution, see The Evolutionary Potency in All Areas of Biology or Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution by looking back--analyzing fossils, comparing species and studying living organisms. However, evolution isn't something that occurred in the past; it's an ongoing process happening today. Viruses evolve to stay away from new medications and bacteria mutate to resist antibiotics. Animals adapt their behavior because of the changing environment. The results are often visible.

However, it wasn't until late-1980s that biologists realized that natural selection can be observed in action as well. The key to this is that different traits confer the ability to survive at different rates as well as reproduction, and may be passed down from one generation to the next.

In the past, if a certain allele - the genetic sequence that determines color - was present in a population of organisms that interbred, it could become 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.

Observing evolutionary change in action is easier when a species has a fast generation turnover, as with bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from one strain. Samples of each population were taken frequently and more than 50,000 generations of E.coli have been observed to have passed.

Lenski's research has revealed that a mutation can profoundly alter the efficiency with the rate at which a population reproduces, and consequently, 에볼루션 바카라 the rate at which it changes. It also shows evolution takes time, which is hard for some to accept.

Another example of microevolution is the way mosquito genes that are resistant to pesticides are more prevalent in populations in which insecticides are utilized. Pesticides create an enticement that favors those who have resistant genotypes.

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