The Academy's Evolution Site

Biological evolution is one of the most central concepts in biology. The Academies are involved in helping those interested in science learn about the theory of evolution and how it can be applied across all areas of scientific research.

This site provides teachers, students and general readers with a wide range of educational resources on evolution. It includes key video clip from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, 에볼루션 슬롯 symbolizes the interconnectedness of all life. It appears in many spiritual traditions and cultures as a symbol of unity and love. It has numerous practical applications in addition to providing a framework for understanding the evolution of species and how they react to changing environmental conditions.

Early approaches to depicting the biological world focused on separating organisms into distinct categories which had been distinguished by their physical and metabolic characteristics1. These methods rely on the collection of various parts of organisms or short DNA fragments, have significantly increased the diversity of a Tree of Life2. These trees are largely composed of eukaryotes, while the diversity of bacterial species is greatly underrepresented3,4.

Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the need for direct observation and experimentation. In particular, molecular methods allow us to construct trees using sequenced markers, such as the small subunit ribosomal gene.

Despite the rapid expansion of the Tree of Life through genome sequencing, 에볼루션 코리아 much biodiversity still awaits discovery. This is especially true for microorganisms that are difficult to cultivate and which are usually only found in one sample5. A recent analysis of all genomes resulted in a rough draft of a Tree of Life. This includes a variety of archaea, bacteria, and other organisms that haven't yet been identified or their diversity is not well understood6.

The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, helping to determine if specific habitats require protection. This information can be used in a variety of ways, including finding new drugs, fighting diseases and improving the quality of crops. This information is also extremely beneficial for conservation efforts. It can aid biologists in identifying the areas that are most likely to contain cryptic species that could have important metabolic functions that may be at risk of anthropogenic changes. While funding to protect biodiversity are important, the most effective way to conserve the world's biodiversity is to equip more people in developing countries with the necessary knowledge to act locally and promote conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the relationships between groups of organisms. By using molecular information similarities and differences in morphology or ontogeny (the proces76229">http://120.zsluoping.Cn/, homologous features into the tree.

Additionally, phylogenetics aids determine the duration and rate of speciation. This information can aid conservation biologists in making choices about which species to protect from extinction. In the end, it is 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 based on their interactions with their surroundings. Many scientists have proposed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would develop according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1844-1829), who believed that the usage or non-use of certain traits can result in changes that are passed on to the

In the 1930s and 1940s, concepts from various fields, including natural selection, genetics, and particulate inheritance -- came together to form the current synthesis of evolutionary theory which explains how evolution happens through the variation of genes within a population and how those variations change over time due to natural selection. This model, which is known as genetic drift mutation, gene flow, and sexual selection, is the foundation of modern evolutionary biology and can be mathematically explained.

Recent developments in evolutionary developmental biology have shown how variation can be introduced to a species by genetic drift, mutations and reshuffling of genes during sexual reproduction and the movement between populations. These processes, along with others, such as directionally-selected selection and erosion of genes (changes in the frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time and changes in phenotype (the expression of genotypes in individuals).

Incorporating evolutionary thinking into all aspects of biology education could increase students' understanding of phylogeny and evolution. A recent study by Grunspan and colleagues, for instance demonstrated that teaching about the evidence that supports evolution helped students accept the concept of evolution in a college-level biology course. For more information about how to teach evolution read The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution through studying fossils, comparing species, and studying living organisms. Evolution is not a distant event; it is an ongoing process that continues to be observed today. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior because of a changing environment. The changes that result are often visible.

It wasn't until the 1980s when biologists began to realize that natural selection was also at work. The key 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 one particular allele--the genetic sequence that defines color in a population of interbreeding organisms, it could quickly become more common than other alleles. In time, this could mean that the number of black moths within a particular population could rise. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to observe evolution when the species, 에볼루션 게이밍 like bacteria, has a rapid generation turnover. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from one strain. Samples of each population were taken regularly, and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has revealed that mutations can drastically alter the speed at which a population reproduces--and so the rate at which it alters. It also shows evolution takes time, something that is hard for some to accept.

Another example of microevolution is the way mosquito genes that confer resistance to pesticides show up more often in populations where insecticides are used. This is due to the fact that the use of pesticides creates a pressure that favors individuals with resistant genotypes.

The rapidity of evolution has led to an increasing appreciation of its importance especially in a planet shaped largely by human activity. This includes pollution, climate change, and habitat loss that hinders many species from adapting. Understanding the evolution process can help us make smarter decisions regarding the future of our planet as well as the life of its inhabitants.