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

The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been active for a long time in helping people who are interested in science understand the theory of evolution and how it permeates all areas of scientific exploration.

This site provides teachers, students and general readers with a wide range of learning resources on evolution. It contains important video clips from NOVA and the WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is used in many spiritual traditions and cultures as symbolizing unity and love. It also has important practical applications, such as providing a framework to understand 에볼루션 블랙잭 the evolution of species and how they respond to changing environmental conditions.

The first attempts at depicting the biological world focused on categorizing organisms into distinct categories which were identified by their physical and metabolic characteristics1. These methods, which are based on the sampling of different parts of organisms or fragments of DNA have greatly increased the diversity of a Tree of Life2. However these trees are mainly made up of eukaryotes. Bacterial diversity is still largely unrepresented3,4.

By avoiding the need for direct experimentation and observation, genetic techniques have made it possible to represent the Tree of Life in a more precise way. In particular, molecular methods allow us to build trees using sequenced markers such as the small subunit of ribosomal RNA gene.

Despite the massive expansion of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is particularly true of microorganisms that are difficult to cultivate and are often only present in a single sample5. A recent analysis of all known genomes has created a rough draft of the Tree of Life, including many archaea and bacteria that have not been isolated, and whose diversity is poorly understood6.

This expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine if certain habitats require protection. The information is useful in a variety of ways, 에볼루션 블랙잭 including finding new drugs, fighting diseases and enhancing crops. It is also valuable in conservation efforts. It helps biologists determine those areas that are most likely contain cryptic species with important metabolic functions that could be vulnerable to anthropogenic change. While funding to protect biodiversity are essential, the best method to preserve the world's biodiversity is to empower the people of developing nations with the knowledge they need to act locally and support conservation.

Phylogeny

A phylogeny (also called an evolutionary tree) shows the relationships between organisms. Scientists can create an phylogenetic chart which shows the evolutionary relationships between taxonomic groups using molecular data and 에볼루션 바카라 무료 morphological differences or similarities. The concept of phylogeny is fundamental to understanding evolution, 에볼루션 바카라 무료체험사이트, please click the following internet site, biodiversity and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that evolved from common ancestors. These shared traits can be either analogous or homologous. Homologous traits are the same in their evolutionary paths. Analogous traits may look like they are, but they do not share the same origins. Scientists group similar traits together into a grouping referred to as a Clade. All organisms in a group have a common characteristic, for example, amniotic egg production. They all evolved from an ancestor who had these eggs. The clades then join to create a phylogenetic tree to determine which organisms have the closest relationship.

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 data is more precise than morphological data and provides evidence of the evolutionary background of an organism or group. Researchers can use Molecular Data to determine the evolutionary age of organisms and determine how many species have an ancestor common to all.

The phylogenetic relationships between organisms can be influenced by several factors including phenotypic plasticity, a type of behavior that changes in response to specific environmental conditions. This can cause a particular trait to appear more similar in one species than another, clouding the phylogenetic signal. This problem can be addressed by using cladistics. This is a method that incorporates a combination of homologous and analogous traits in the tree.

Additionally, phylogenetics can help determine the duration and rate at which speciation occurs. This information can assist conservation biologists decide the species they should safeguard from the threat of extinction. In the end, it's the conservation of phylogenetic diversity that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

The main idea behind evolution is that organisms acquire various characteristics over time due to their interactions with their environment. Several theories of evolutionary change have been developed by a wide variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve gradually according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that could be passed onto offspring.

In the 1930s and 1940s, theories from various fields, including genetics, natural selection, and particulate inheritance -- came together to form the current synthesis of evolutionary theory, which defines how evolution happens through the variation of genes within a population and how these variants change over time due to natural selection. This model, which encompasses mutations, genetic drift in gene flow, and 에볼루션 블랙잭 sexual selection, can be mathematically described.

Recent discoveries in the field of evolutionary developmental biology have shown that genetic variation can be introduced into a species through genetic drift, mutation, and reshuffling of genes during sexual reproduction, as well as through the movement of populations. These processes, along with other ones like directional selection and genetic erosion (changes in the frequency of the genotype over time) can result in evolution that is defined as change in the genome of the species over time and also the change in phenotype over time (the expression of the genotype within the individual).

Students can better understand 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 boosted their understanding of evolution in an undergraduate biology course. For more information about how to teach evolution look up The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily as a Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution through looking back--analyzing fossils, comparing species, and studying living organisms. But evolution isn't just something that occurred in the past, it's an ongoing process that is happening in the present. Bacteria evolve and resist antibiotics, viruses re-invent themselves and elude new medications, and animals adapt their behavior in response to a changing planet. The results are often apparent.

But it wasn't until the late 1980s that biologists realized that natural selection could be seen in action, as well. The reason 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 an allele - the genetic sequence that determines colour was found in a group of organisms that interbred, it could become more common than any other allele. In time, this could 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.

Observing evolutionary change in action is easier when a species has a rapid turnover of its generation like bacteria. 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 on a regular basis and over 50,000 generations have now been observed.

Lenski's research has revealed that mutations can drastically alter the rate at which a population reproduces and, consequently, the rate at which it evolves. It also demonstrates that evolution takes time, which is difficult for some to accept.

Another example of microevolution is the way mosquito genes that are resistant to pesticides show up more often in populations where insecticides are employed. Pesticides create an enticement that favors those with resistant genotypes.

The rapidity of evolution has led to an increasing recognition of its importance, especially in a world which is largely shaped by human activities. This includes the effects of climate change, pollution and habitat loss that prevents many species from adapting. Understanding the evolution process can help us make smarter decisions about the future of our planet and the lives of its inhabitants.