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20 Resources That'll Make You More Efficient With Evolution Site
The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies have long been involved in helping people who are interested in science understand the theory of evolution and how it influences all areas of scientific exploration.

This site provides students, teachers 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 is an ancient symbol that symbolizes the interconnectedness of life. It is a symbol of love and harmony in a variety of cultures. It has many practical applications as well, including providing a framework for understanding the history of species and how they react to changes in environmental conditions.

Early approaches to depicting the world of biology focused on categorizing species into distinct categories that were distinguished by physical and metabolic characteristics1. These methods, which are based on the sampling of different parts of organisms, or DNA fragments have greatly increased the diversity of a Tree of Life2. These trees are largely composed of eukaryotes, while bacteria are largely underrepresented3,4.

Genetic techniques have greatly broadened our ability to depict the Tree of Life by circumventing the need for direct observation and experimentation. Particularly, molecular techniques allow us to construct trees using sequenced markers, such as the small subunit ribosomal RNA gene.

The Tree of Life has been significantly expanded by genome sequencing. However, there is still much diversity to be discovered. This is especially true for microorganisms that are difficult to cultivate and are usually present in a single sample5. Recent analysis of all genomes has produced an initial draft of the Tree of Life. This includes a large number of archaea, bacteria and other organisms that have not yet been isolated, or whose diversity has not been well understood6.

The expanded Tree of Life can be used to determine the diversity of a specific region and determine if specific habitats need special protection. This information can be used in a variety of ways, including identifying new drugs, combating diseases and improving crops. This information is also extremely valuable to conservation efforts. It helps biologists discover areas that are most likely to have cryptic species, which may have vital metabolic functions, and could be susceptible to human-induced change. While conservation funds are important, the best way to conserve the biodiversity of the world is to equip more people in developing countries with the necessary knowledge to act locally and support conservation.

Phylogeny

A phylogeny (also called an evolutionary tree) depicts the relationships between organisms. By using molecular information similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can construct an phylogenetic tree that demonstrates the evolution of taxonomic groups. Phylogeny is essential in understanding evolution, biodiversity and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 ) identifies the relationships between organisms that share similar traits that evolved from common ancestral. These shared traits are either homologous or analogous. Homologous traits share their evolutionary origins and analogous traits appear like they do, but don't have the same origins. Scientists put similar traits into a grouping called a clade. For instance, all the organisms that make up a clade share the characteristic of having amniotic eggs. They evolved from a common ancestor who had eggs. The clades are then linked to create a phylogenetic tree to determine the organisms with the closest relationship.

Scientists make use of DNA or RNA molecular data to construct a phylogenetic graph which is more precise and precise. This information is more precise and gives evidence of the evolution of an organism. Molecular data allows researchers to determine the number of organisms who share an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationship can be affected by a number of factors, including phenotypicplasticity. This is a type of behaviour that can change in response to particular environmental conditions. This can cause a characteristic to appear more like a species another, clouding the phylogenetic signal. This problem can be mitigated by using cladistics. This is a method that incorporates a combination of homologous and analogous traits in the tree.


Additionally, phylogenetics aids predict the duration and rate of speciation. This information will assist conservation biologists in making decisions about which species to protect from disappearance. In the end, it's the conservation of phylogenetic variety which will create an ecosystem that is complete and balanced.

Evolutionary Theory

The main idea behind evolution is that organisms change over time as a result of their interactions with their environment. 에볼루션코리아 of theories about evolution have been proposed by a wide range of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that could be passed on to the offspring.

In the 1930s and 1940s, theories from a variety of fields--including natural selection, genetics, and particulate inheritance -- came together to create the modern synthesis of evolutionary theory that explains how evolution happens through the variation of genes within a population and how these variants change over time as a result of natural selection. This model, called genetic drift mutation, gene flow and sexual selection, is a key element of the current evolutionary biology and can be mathematically explained.

Recent discoveries in the field of evolutionary developmental biology have shown that variation can be introduced into a species via genetic drift, mutation, and reshuffling of genes in sexual reproduction, and also through migration between populations. These processes, along with others, such as directionally-selected selection and erosion of genes (changes to the frequency of genotypes over time), can lead towards evolution. Evolution is defined as changes in the genome over time and changes in the phenotype (the expression of genotypes within individuals).

Incorporating evolutionary thinking into all aspects of biology education can increase students' understanding of phylogeny and evolution. In a recent study 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 on how to teach about evolution, please read The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Traditionally, scientists have studied evolution through looking back, studying fossils, comparing species and observing living organisms. However, evolution isn't something that occurred in the past, it's an ongoing process taking place today. Bacteria mutate and resist antibiotics, viruses evolve and are able to evade new medications and animals change their behavior to a changing planet. The results are often visible.

It wasn't until the late 1980s when biologists began to realize that natural selection was in play. The key is that various characteristics result in different rates of survival and reproduction (differential fitness) and can be transferred from one generation to the next.

In the past when one particular allele--the genetic sequence that defines color in a population of interbreeding organisms, it might quickly become more common than the other alleles. Over time, that would mean 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.

Observing evolutionary change in action is easier when a species has a rapid generation turnover, as with bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from a single strain. Samples of each population have been taken regularly and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has revealed that a mutation can profoundly alter the efficiency with which a population reproduces--and so, the rate at which it changes. It also demonstrates that evolution is slow-moving, a fact that some people find difficult 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 the fact that the use of pesticides creates a selective pressure that favors people who have resistant genotypes.

The rapid pace at which evolution takes place has led to a growing appreciation of its importance in a world shaped by human activity, including climate change, pollution, and the loss of habitats that prevent many species from adapting. Understanding evolution can help us make smarter decisions regarding the future of our planet, as well as the lives of its inhabitants.