The Academy's Evolution Site

The concept of biological evolution is a fundamental concept in biology. The Academies have been for a long time involved in helping people who are interested in science comprehend the theory of evolution and how it affects all areas of scientific research.

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

Tree of Life

The Tree of Life is an ancient symbol that symbolizes the interconnectedness of all life. It is an emblem of love and harmony in a variety of cultures. It can be used in many practical ways in addition to providing a framework for understanding the history of species and how they respond to changing environmental conditions.

Early attempts to describe the world of biology 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 sequences of small fragments of their DNA, greatly increased the variety of organisms that could be represented in the tree of life2. The trees are mostly composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4.

By avoiding the necessity for direct experimentation and observation, genetic techniques have allowed us to depict the Tree of Life in a much more accurate way. Trees can be constructed using molecular methods like the small-subunit ribosomal gene.

Despite the rapid growth of the Tree of Life through genome sequencing, a lot of biodiversity is waiting to be discovered. This is particularly true for microorganisms that are difficult to cultivate and which are usually only found in a single specimen5. A recent study of all genomes that are known has produced a rough draft version of the Tree of Life, including many bacteria and archaea that are not isolated and their diversity is not fully understood6.

The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, assisting to determine if specific habitats require special protection. The information is useful in many ways, including finding new drugs, fighting diseases and improving crops. It is also useful for conservation efforts. It can aid biologists in identifying those areas that are most likely contain cryptic species that could have significant metabolic functions that could be vulnerable to anthropogenic change. While funding to protect biodiversity are important, the best method to protect the world's biodiversity is to equip the people of developing nations with the knowledge they need to act locally and promote conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, reveals the connections between various groups of organisms. Scientists can build a phylogenetic chart that shows the evolutionary relationship of taxonomic categories using molecular information and morphological similarities or differences. Phylogeny is essential in understanding the evolution of biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits thatbr/>Evolutionary Theory

The central theme of evolution is that organisms acquire different features over time as a result of their interactions with their surroundings. Many scientists have developed theories of evolution, 에볼루션게이밍 including the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could evolve according to its own needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who believed that the usage or non-use of traits can cause changes that can be passed on to future generations.

In the 1930s and 1940s, ideas from a variety of fields--including genetics, natural selection and particulate inheritance--came together to create the modern synthesis of evolutionary theory, 에볼루션 카지노 which defines how evolution happens through the variations of genes within a population, and how these variants change in time as a result of natural selection. This model, which encompasses mutations, genetic drift as well as gene flow and sexual selection is mathematically described.

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

Incorporating evolutionary thinking into all areas of biology education can improve students' understanding of phylogeny and evolution. A recent study by Grunspan and colleagues, for instance, showed that teaching about the evidence for 에볼루션 게이밍 evolution helped students accept the concept of evolution in a college biology class. For more information about how to teach evolution look up The Evolutionary Potential 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 through looking back--analyzing 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 medications and bacteria mutate to resist antibiotics. Animals alter their behavior as a result of a changing environment. The changes that result are often visible.

It wasn't until late 1980s that biologists understood that natural selection could be seen in action, as well. The key is the fact that different traits can confer a different rate of survival as well as reproduction, and may be passed down from one generation to the next.

In the past, if one allele - the genetic sequence that determines colour was found in a group of organisms that interbred, it could be more prevalent than any other allele. As time passes, that could mean that the number of black moths in 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 track evolution when a species, such as bacteria, has a rapid generation turnover. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from one strain. Samples from each population have been collected frequently and more than 500.000 generations of E.coli have passed.

Lenski's work has demonstrated that mutations can drastically alter the rate at the rate at which a population reproduces, and consequently, the rate at which it alters. It also proves that evolution is slow-moving, a fact that some people are unable to accept.

Microevolution can also be seen in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides have been used. This is due to pesticides causing an exclusive pressure that favors those who have resistant genotypes.

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