The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been for a long time 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 has the most 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 a symbol of love and unity across many cultures. It also has practical applications, such as providing a framework for understanding the history of species and how they respond to changes in the environment.

Early attempts to represent the world of biology were based on categorizing organisms based on their metabolic and physical characteristics. These methods depend 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 mostly populated by eukaryotes and the diversity of bacterial species is greatly underrepresented3,4.

By avoiding the necessity for direct observation and experimentation genetic techniques have made it possible to depict the Tree of Life in a more precise way. Trees can be constructed by using molecular methods such as the small subunit ribosomal gene.

Despite the rapid expansion of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are usually only represented in a single specimen5. Recent analysis of all genomes has produced an initial draft of the Tree of Life. This includes a variety of archaea, bacteria and other organisms that haven't yet been isolated, or the diversity of which is not fully understood6.

This expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if particular habitats need special protection. This information can be utilized in a range of ways, from identifying new medicines to combating disease to improving the quality of crops. The information is also incredibly beneficial to conservation efforts. It can help biologists identify the areas most likely to contain cryptic species with important metabolic functions that may be vulnerable to anthropogenic change. Although funding to protect biodiversity are essential but the most effective way to protect the world's biodiversity is for more people in developing countries to be equipped with the knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, shows the connections between groups of organisms. By using molecular information as well as morphological similarities and distinctions or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree which illustrates the evolution of taxonomic groups. The concept of phylogeny is fundamental to understanding biodiversity, evolution and the phenotypic plasticity. This is a kind of behavior that alters due to unique environmental conditions. This can cause a characteristic to appear more similar to one species than another, clouding the phylogenetic signal. However, this problem can be solved through the use of methods like cladistics, which incorporate a combination of analogous and homologous features into the tree.

Additionally, phylogenetics aids determine the duration and 에볼루션바카라 speed of speciation. This information can assist conservation biologists decide which species they should protect from extinction. In the end, it is the conservation of phylogenetic variety that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

The central theme of evolution is that organisms develop different features over time as a result of their interactions with their environments. Many scientists have proposed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could develop according to its own requirements, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of certain traits can result in changes that are passed on to the next generation.

In the 1930s and 1940s, theories from various fields, including genetics, natural selection, 무료 에볼루션 and particulate inheritance -- came together to create the modern evolutionary theory synthesis, which defines how evolution is triggered by the variation of genes within a population and how these 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 explained.

Recent developments in the field of evolutionary developmental biology have demonstrated that genetic variation can be introduced into a species by genetic drift, mutation, and reshuffling genes during sexual reproduction, as well as through the movement of populations. These processes, as well as others such as directional selection and gene erosion (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 an individual).

Students can better understand the concept of phylogeny by using evolutionary thinking into all aspects of biology. In a recent study conducted by Grunspan et al. It was found that teaching students about the evidence for evolution boosted their acceptance of evolution during an undergraduate biology course. For more information on how to teach about evolution, see The Evolutionary Potency in All Areas of Biology or Thinking Evolutionarily: a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Traditionally, scientists have studied evolution by looking back--analyzing fossils, comparing species, and studying living organisms. However, evolution isn't something that happened in the past; it's an ongoing process that is taking place in the present. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior in the wake of a changing environment. The changes that result are often evident.

It wasn't until the 1980s that biologists began to realize that natural selection was in action. The key to this is that different traits result in an individual rate of survival as well as reproduction, and may be passed down from one generation to another.

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 prevalent than the other alleles. As time passes, that could mean that the number of black moths within 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, as with bacteria. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. Coli that descended from a single strain. samples of each are taken on a regular basis and more than fifty thousand generations have been observed.

Lenski's research has revealed that mutations can alter the rate of change and the rate of a population's reproduction. It also demonstrates that evolution takes time--a fact that many find difficult to accept.

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

The rapid pace at which evolution takes place has led to an increasing recognition of its importance in a world that is shaped by human activities, including climate change, pollution, and the loss of habitats that prevent many species from adapting. Understanding evolution will help us make better decisions about the future of our planet, and the life of its inhabitants.