The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies have been for a long time involved in helping people who are interested in science understand the concept of evolution and how it permeates all areas of scientific research.

This site provides a wide range of sources for students, teachers and general readers of evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of all life. It is used in many spiritual traditions and cultures as an emblem of unity and love. It also has important practical uses, like providing a framework for understanding the evolution of species and how they react to changes in the environment.

The first attempts to depict the biological world were founded on categorizing organisms on their physical and metabolic characteristics. These methods, which rely on the sampling of different parts of living organisms, or sequences of small DNA fragments, significantly expanded the diversity that could be included in a tree of life2. However the trees are mostly composed of eukaryotes; bacterial diversity is not represented in a large way3,4.

Genetic techniques have significantly expanded our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular techniques allow us to build trees by using sequenced markers such as the small subunit of ribosomal RNA gene.

Despite the dramatic growth of the Tree of Life through genome sequencing, much biodiversity still awaits discovery. This is especially relevant to microorganisms that are difficult to cultivate, and 에볼루션 사이트 (http://www.Neumannlawoffices.com) are usually present in a single sample5. A recent analysis of all genomes resulted in an unfinished draft of the Tree of Life. This includes a large number of archaea, bacteria, and other organisms that haven't yet been isolated or whose diversity has not been fully understood6.

The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, helping to determine if specific habitats require protection. This information can be used in many ways, including finding new drugs, battling diseases and enhancing crops. This information is also extremely valuable for conservation efforts. It helps biologists discover areas most likely to be home to cryptic species, which could have important metabolic functions, and could be susceptible to human-induced change. While funding to protect biodiversity are important, the most effective method to preserve the biodiversity of the world 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) shows the relationships between species. Scientists can build a phylogenetic chart that shows the evolutionary relationship of taxonomic groups using molecular data and morphological similarities or differences. Phylogeny is essential in understanding the evolution of biodiversity, evolution and 에볼루션 바카라 무료체험 genetics.

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 homologous, or analogous. Homologous characteristics are identical in their evolutionary path. Analogous traits may look similar however they do not have the same ancestry. Scientists combine similar traits into a grouping called a Clade. Every organism in a group share a characteristic, for example, amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree can be constructed by connecting clades to identify the species who are the closest to one another.

To create a more thorough and accurate phylogenetic tree scientists use molecular data from DNA or RNA to establish the relationships between organisms. This information is more precise and gives evidence of the evolution of an organism. Researchers can utilize Molecular Data to calculate the age of evolution of organisms and identify the number of organisms that have a common ancestor.

The phylogenetic relationship can be affected by a number of factors that include phenotypicplasticity. This is a type behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar to a species than another and obscure the phylogenetic signals. However, this issue can be cured by the use of methods such as cladistics which combine similar and homologous traits into the tree.

Additionally, phylogenetics can aid in predicting the length and speed of speciation. This information can aid conservation biologists in deciding which species to save from the threat of extinction. Ultimately, it is the preservation of phylogenetic diversity which will result in an ecologically balanced and complete ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms change over time as a result of their interactions with their environment. 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 as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical system of taxonomy, 에볼루션카지노사이트; www.lawandorder.biz, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of traits can cause changes that are passed on to the

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

Recent developments in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species by mutation, genetic drift, and reshuffling genes during sexual reproduction, as well as by migration between populations. These processes, along with other ones like directional selection and genetic erosion (changes in the frequency of the genotype over time), can lead to 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 the genotype in the individual).

Incorporating evolutionary thinking into all areas of biology education can increase students' understanding of phylogeny as well as evolution. A recent study conducted by Grunspan and colleagues, for example demonstrated that teaching about the evidence that supports evolution increased students' understanding 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 the Concept of Evolution into Life Sciences Education.

Evolution in Action

Scientists have traditionally looked at evolution through the past--analyzing fossils and comparing species. They also observe living organisms. But evolution isn't a thing that happened in the past, it's an ongoing process that is happening today. Bacteria evolve and 에볼루션 코리아 resist antibiotics, viruses re-invent themselves and are able to evade new medications and animals change their behavior in response to the changing environment. The changes that result are often easy to see.

But it wasn't until the late 1980s that biologists understood that natural selection can be seen in action, as well. The main reason is that different traits result in the ability to survive at different rates and reproduction, and 에볼루션 코리아 can be passed down from generation to generation.

In the past, if a certain allele - the genetic sequence that determines color - appeared in a population of organisms that interbred, it might become more common than any other allele. In time, this could mean that the number of moths with black pigmentation in a group may increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

The ability to observe evolutionary change is easier when a species has a rapid generation turnover like bacteria. Since 1988, Richard Lenski, 에볼루션 코리아 a biologist, has studied twelve populations of E.coli that are descended from a single strain. Samples of each population have been taken regularly, and more than 50,000 generations of E.coli have passed.

Lenski's research has revealed that mutations can alter the rate of change and the efficiency at which a population reproduces. It also shows that evolution takes time, a fact that is difficult for some to accept.

Another example of microevolution is how mosquito genes that are resistant to pesticides show up more often in populations where insecticides are employed. This is because the use of pesticides creates a pressure that favors people with resistant genotypes.

The rapid pace of evolution taking place has led to an increasing awareness of its significance in a world shaped by human activities, including climate changes, pollution and the loss of habitats which prevent many species from adjusting. Understanding evolution can help us make better choices about the future of our planet as well as the life of its inhabitants.