• 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 who are interested in science to comprehend the evolution theory and how it is permeated in all areas of scientific research.

This site offers a variety of tools for students, teachers as well as general readers about evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

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

Early attempts to describe the biological world were founded on categorizing organisms on their metabolic and physical characteristics. These methods, which relied on the sampling of different parts of living organisms or on sequences of small fragments of their DNA, significantly expanded the diversity that could be included in the tree of life2. However, these trees are largely composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4.

By avoiding the necessity for direct observation and experimentation, genetic techniques have allowed us to represent the Tree of Life in a more precise manner. Trees can be constructed using molecular methods such as the small subunit ribosomal gene.

The Tree of Life has been significantly expanded by genome sequencing. However, there is still much diversity to be discovered. This is especially the case for microorganisms which are difficult to cultivate and are usually present in a single sample5. Recent analysis of all genomes has produced an unfinished draft of the Tree of Life. This includes a large number of bacteria, archaea and other organisms that haven't yet been identified or whose diversity has not been thoroughly understood6.

This expanded Tree of Life can be used to assess the biodiversity of a specific region and determine if specific habitats need special protection. This information can be utilized in a variety of ways, such as identifying new drugs, combating diseases and enhancing crops. This information is also beneficial for conservation efforts. It helps biologists determine the areas most likely to contain cryptic species that could have important metabolic functions that could be vulnerable to anthropogenic change. Although funding to safeguard biodiversity are vital, ultimately the best way 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 called an evolutionary tree) illustrates the relationship between organisms. Scientists can build an phylogenetic chart which shows the evolutionary relationship of taxonomic categories using molecular information and morphological similarities or differences. The phylogeny of a tree plays an important role in understanding genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms that have similar traits and evolved from an ancestor with common traits. These shared traits could be analogous, or homologous. Homologous traits are the same in terms of their evolutionary path. Analogous traits may look like they are, but they do not share the same origins. Scientists group similar traits into a grouping called a the clade. All organisms in a group have a common characteristic, for example, amniotic egg production. They all evolved from an ancestor that had these eggs. A phylogenetic tree is then built by connecting the clades to identify the organisms that are most closely related to one another.

To create a more thorough and accurate phylogenetic tree, scientists rely on molecular information from DNA or RNA to identify the connections between organisms. This information is more precise and provides evidence of the evolution of an organism. The use of molecular data lets researchers determine the number of organisms that have an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships between organisms can be affected by a variety of factors, including phenotypic flexibility, an aspect of behavior that changes in response to specific environmental conditions. This can cause a particular trait to appear more similar in one species than other species, which can obscure the phylogenetic signal. This problem can be addressed by using cladistics, which incorporates a combination of homologous and analogous traits in the tree.

In addition, phylogenetics helps determine the duration and speed at which speciation takes place. This information can aid conservation biologists in deciding which species to protect from extinction. In the end, it's the preservation of phylogenetic diversity that will create a complete and balanced ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms develop distinct characteristics over time due to their interactions with their environments. 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 would evolve according to its own requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the usage or non-use of traits can lead to changes that are passed on to the next generation.

In the 1930s & 1940s, theories from various fields, such as genetics, natural selection, and particulate inheritance, merged to form a contemporary theorizing of evolution. This defines how evolution is triggered by the variation in genes within the population, and how these variants change over time as a result of natural selection. This model, which incorporates genetic drift, mutations, gene flow and 에볼루션카지노사이트 sexual selection is mathematically described.

Recent discoveries in evolutionary developmental biology have revealed the ways in which variation can be introduced to a species by genetic drift, mutations and reshuffling of genes during sexual reproduction and migration between populations. These processes, 에볼루션 슬롯게임 슬롯 (Click4R.Com) as well as others such as directional selection or genetic erosion (changes in the frequency of a 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 that genotype in the individual).

Incorporating evolutionary thinking into all aspects of biology education can improve students' understanding of phylogeny and evolutionary. In a study by Grunspan et al., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during an undergraduate biology course. For more information on how to teach about evolution, read The Evolutionary Potential in all Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Scientists have traditionally studied evolution by looking in the past, studying fossils, and comparing species. They also observe living organisms. Evolution is not a distant event; it is a process that continues today. Bacteria transform and resist antibiotics, viruses re-invent themselves and escape new drugs and 에볼루션바카라 animals change their behavior to the changing environment. The results are often evident.

It wasn't until the 1980s that biologists began to realize that natural selection was also at work. The reason is that different traits have different rates of survival and reproduction (differential fitness) and can be passed from one generation to the next.

In the past, if a certain allele - the genetic sequence that determines colour - was present in a population of organisms that interbred, it might become more common than other allele. Over time, this would mean that the number of moths with 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 evolution when a species, such as 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 population are taken every day and over 50,000 generations have now passed.

Lenski's work has demonstrated that a mutation can dramatically alter the rate at the rate at which a population reproduces, and consequently, the rate at which it evolves. It also shows that evolution takes time, something that is hard for some to accept.

Another example of microevolution is that mosquito genes that are resistant to pesticides are more prevalent in areas in which insecticides are utilized. This is because the use of pesticides causes a selective pressure that favors individuals who have resistant genotypes.

The rapid pace of evolution taking place has led to a growing recognition of its importance in a world that is shaped by human activities, 에볼루션 게이밍 including climate change, pollution and 에볼루션 카지노 the loss of habitats that prevent many species from adapting. Understanding the evolution process can help you make better decisions about the future of our planet and its inhabitants.