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

The Academy's Evolution Site

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

This site provides a wide range of resources for students, teachers, and general readers on evolution. It includes the most 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 a symbol of love and unity in many cultures. It can be used in many practical ways as well, such as providing a framework for understanding the history of species and 무료 에볼루션 게이밍 (www.aupeopleweb.com.au) how they react to changes in environmental conditions.

Early attempts to describe the biological world were built on categorizing organisms based on their metabolic and physical characteristics. These methods, which rely on the collection of various parts of organisms or DNA fragments, have greatly increased the diversity of a tree of Life2. The trees are mostly composed by eukaryotes, and bacterial diversity is 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 much more accurate way. Trees can be constructed using molecular methods such as the small subunit ribosomal gene.

Despite the dramatic growth of the Tree of Life through genome sequencing, a lot of biodiversity remains to be discovered. This is particularly true of microorganisms, which can be difficult to cultivate and are typically only present in a single sample5. A recent analysis of all known genomes has produced a rough draft version of the Tree of Life, including numerous bacteria and archaea that have not been isolated and which are not well understood.

This expanded Tree of Life can be used to determine the diversity of a particular area and determine if particular habitats need special protection. The information is useful in many ways, including finding new drugs, fighting diseases and improving the quality of crops. The information is also beneficial to conservation efforts. It can aid biologists in identifying areas that are most likely to be home to cryptic species, 에볼루션 슬롯게임 which may perform important metabolic functions and be vulnerable to the effects of human activity. Although funding to safeguard biodiversity are vital however, the most effective method to ensure the preservation of biodiversity around the world is for more people in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, shows the relationships between various groups of organisms. Scientists can construct a phylogenetic chart that shows the evolutionary relationships between taxonomic groups using molecular data and morphological similarities or differences. The phylogeny of a tree plays an important role in understanding biodiversity, genetics and evolution.

A basic phylogenetic tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that evolved from common ancestors. These shared traits may be analogous, or homologous. Homologous traits are the same in their evolutionary paths. Analogous traits may look similar, but they do not share the same origins. Scientists group similar traits into a grouping referred to as a Clade. For instance, all of the organisms that make up a clade share the trait 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 who are the closest to each other.

To create a more thorough and precise phylogenetic tree scientists use molecular data from DNA or RNA to establish the connections between organisms. This data is more precise than morphological information and provides evidence of the evolutionary history of an organism or group. Molecular data allows researchers to determine the number of organisms who share the same ancestor and estimate their evolutionary age.

The phylogenetic relationships between organisms are influenced by many factors including phenotypic plasticity, a kind of behavior that alters in response to unique environmental conditions. This can cause a trait to appear more similar to one species than another which can obscure the phylogenetic signal. This problem can be mitigated by using cladistics, which incorporates a combination of analogous and homologous features in the tree.

In addition, phylogenetics helps determine the duration and speed at which speciation takes place. This information can help conservation biologists decide which species to protect from extinction. It is ultimately the preservation of phylogenetic diversity which will lead to a complete and balanced ecosystem.

Evolutionary Theory

The fundamental concept in evolution is that organisms alter over time because of their interactions with their environment. Many theories of evolution have been developed by a wide variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who envisioned an organism developing slowly in accordance with its requirements, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits causes changes that can be passed onto 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 occurs through the variation of genes within a population and how those variants change over time due to natural selection. This model, which is known as genetic drift mutation, gene flow and sexual selection, is a cornerstone of modern evolutionary biology and can be mathematically explained.

Recent advances in evolutionary developmental biology have shown how variations can be introduced to a species via genetic drift, mutations and reshuffling of genes during sexual reproduction and the movement between populations. These processes, in conjunction with other ones like directionally-selected selection and erosion of genes (changes in frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes in an individual).

Incorporating evolutionary thinking into all aspects of biology education can increase students' understanding of phylogeny as well as evolution. A recent study by Grunspan and colleagues, for example revealed that teaching students about the evidence supporting evolution increased students' acceptance of evolution in a college biology class. For more information on how to teach about evolution, see The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have looked at evolution through the past, studying fossils, and comparing species. They also study living organisms. But evolution isn't a thing that happened in the past. It's an ongoing process happening right now. Viruses reinvent themselves to avoid new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior as a result of the changing environment. The changes that result are often evident.

But it wasn't until the late 1980s that biologists realized that natural selection could be seen in action, as well. The key is that various traits confer different rates of survival and reproduction (differential fitness) and can be passed down from one generation to the next.

In the past, when one particular allele, the genetic sequence that controls coloration - was present in a group of interbreeding organisms, it might rapidly become more common than other alleles. As time passes, that could mean the number of black moths within the population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to see evolution when the species, like bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has been tracking twelve populations of E.coli that descend from a single strain. The samples of each population have been collected regularly and more than 50,000 generations of E.coli have passed.

Lenski's work has shown that mutations can alter the rate of change and the rate at which a population reproduces. It also demonstrates that evolution takes time, something that is difficult for some to accept.

Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more common in populations where insecticides have been used. Pesticides create an enticement that favors those with resistant genotypes.

The rapid pace at which evolution can take place has led to a growing recognition of its importance in a world that is shaped by human activities, including climate changes, pollution and the loss of habitats which prevent many species from adapting. Understanding the evolution process can help us make better choices about the future of our planet, and 에볼루션 블랙잭 the life of its inhabitants.