The Academy's Evolution Site

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

This site provides a wide range of resources for teachers, students 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 symbolizes the interconnectedness of life. It is an emblem of love and unity across many cultures. It also has practical applications, like providing a framework to understand the history of species and how they react to changes in environmental conditions.

Early attempts to describe the world of biology were built on categorizing organisms based on their metabolic and physical characteristics. These methods, based on the sampling of various parts of living organisms or sequences of short fragments of their DNA significantly increased the variety that could be represented in a tree of life2. These trees are mostly populated of eukaryotes, while bacteria are largely underrepresented3,4.

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

The Tree of Life has been greatly expanded thanks to genome sequencing. However, there is still much diversity to be discovered. This is particularly true of microorganisms, which are difficult to cultivate and are typically only present in a single specimen5. Recent analysis of all genomes has produced a rough 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 thoroughly understood6.

The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, assisting to determine whether specific habitats require protection. This information can be utilized in a range of ways, from identifying the most effective treatments to fight disease to improving crop yields. The information is also incredibly valuable to conservation efforts. It helps biologists discover areas that are most likely to be home to species that are cryptic, which could perform important metabolic functions, and could be susceptible to changes caused by humans. While funds to safeguard biodiversity are vital but the most effective way to protect the world's biodiversity is for more people in developing countries to be empowered with the necessary knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the connections between various groups of organisms. Scientists can construct a phylogenetic diagram that illustrates the evolutionary relationships bsts in deciding which species to save from extinction. It is ultimately the preservation of phylogenetic diversity that will create a complete and balanced ecosystem.

Evolutionary Theory

The central theme in evolution is that organisms change over time due to their interactions with their environment. Many theories of 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 gradually according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or misuse of traits causes changes that could be passed on to the offspring.

In the 1930s and 1940s, concepts from various fields, such as genetics, natural selection, and particulate inheritance, merged to form a modern evolutionary theory. This defines how evolution happens through the variation of genes in a population and how these variations change with time due to natural selection. This model, known as genetic drift mutation, gene flow, and sexual selection, is the foundation of current evolutionary biology, and can be mathematically described.

Recent discoveries in the field of evolutionary developmental biology have revealed how variation can be introduced to a species via genetic drift, mutations or reshuffling of genes in sexual reproduction, and even migration between populations. These processes, as well as others such as the directional selection process and the erosion of genes (changes in frequency of genotypes over time) can result in evolution. Evolution is defined as changes in the genome over time as well as changes in phenotype (the expression of genotypes in individuals).

Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny and evolutionary. In a recent study conducted by Grunspan and co. It was found that teaching students about the evidence for evolution boosted their understanding of evolution in an undergraduate biology course. To learn more about how to teach about evolution, look up The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Scientists have studied evolution by looking in the past, analyzing fossils and comparing species. They also study living organisms. Evolution is not a past event; it is an ongoing process. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals alter their behavior 에볼루션 게이밍사이트 (Https://www.metooo.io/u/676928cb52a62011e855fc21) in the wake of the changing environment. The changes that occur are often apparent.

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

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

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

Lenski's work has demonstrated that a mutation can profoundly alter the efficiency with 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 find difficult to accept.

Another example of microevolution is how mosquito genes for resistance to pesticides appear more frequently in populations where insecticides are employed. Pesticides create an exclusive pressure that favors those who have resistant genotypes.

The rapid pace of evolution taking place has led to an increasing awareness of its significance in a world that is shaped by human activity, including climate change, pollution, 에볼루션 사이트 (click4r.com) and the loss of habitats which prevent the species from adapting. Understanding evolution can help us make better decisions about the future of our planet, as well as the life of its inhabitants.