The Academy's Evolution Site

The concept of biological evolution is among the most fundamental concepts in biology. The Academies are involved in helping those interested in science to understand evolution theory and how it is incorporated across all areas of scientific research.

This site provides teachers, students and general readers with a range of learning resources on evolution. It contains key video clips from NOVA and WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It appears in many spiritual traditions and cultures as an emblem of unity and love. It also has practical applications, like providing a framework for understanding the history of species and how they react to changes in environmental conditions.

The earliest attempts to depict the world of biology focused on separating organisms into distinct categories that had been distinguished by their physical and metabolic characteristics1. These methods, which rely on the sampling of different parts of organisms or DNA fragments have significantly increased the diversity of a tree of Life2. However, these trees are largely comprised of eukaryotes, and 에볼루션 코리아 bacterial diversity remains vastly underrepresented3,4.

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

Despite the rapid growth of the Tree of Life through genome sequencing, a large amount of biodiversity awaits discovery. This is particularly true for microorganisms, which are difficult to cultivate and are usually only found in a single sample5. Recent analysis of all genomes has produced a rough draft of a Tree of Life. This includes a large number of archaea, bacteria, and other organisms that haven't yet been isolated, or their diversity is not fully understood6.

This expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine whether specific habitats require protection. This information can be utilized in a variety of ways, including identifying new drugs, combating diseases and enhancing crops. This information is also beneficial to conservation efforts. It can help biologists identify areas that are likely to have cryptic species, which may perform important metabolic functions and are susceptible to changes caused by humans. Although funds to protect biodiversity are essential but the most effective way to preserve the world's biodiversity is for more people living in developing countries to be empowered with the knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the connections between different groups of organisms. Utilizing molecular data 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 categories. Thehondacityclub.com/all_new/home.php?mod=space&uid=2092541">에볼루션 슬롯코리아 (Http://Wzgroupup.Hkhz76.Badudns.Cc/) phylogenetics aids determine the duration and speed at which speciation occurs. This information can aid conservation biologists to decide the species they should safeguard from the threat of extinction. In the end, it is the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced.

Evolutionary Theory

The fundamental concept of evolution is that organisms develop various characteristics over time due to their interactions with their environments. Many scientists have come up with theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism would evolve according to its individual requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or non-use of traits can lead to changes that are passed on to the

In the 1930s & 1940s, theories from various areas, including natural selection, genetics & particulate inheritance, merged to form a modern synthesis of evolution theory. This describes how evolution happens through the variation in genes within the population, and how these variants change with time due to natural selection. This model, which is known as genetic drift mutation, gene flow, and sexual selection, is the foundation of modern 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 via mutation, 에볼루션코리아 genetic drift and reshuffling genes during sexual reproduction, as well as by migration between populations. These processes, along with others such as directional selection or genetic erosion (changes in the frequency of an individual's genotype over time), can lead to evolution which is defined by changes in the genome of the species over time and also by changes in phenotype over time (the expression of the genotype within the individual).

Incorporating evolutionary thinking into all areas of biology education could increase student understanding of the concepts of phylogeny as well as evolution. In a recent study by Grunspan et al. It was found that teaching students about the evidence for evolution increased their acceptance of evolution during the course of a college biology. To learn more about how to teach about evolution, please read The Evolutionary Potential of All Areas of Biology and 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 observing living organisms. Evolution isn't a flims event; it is an ongoing process. Bacteria transform and resist antibiotics, viruses evolve and elude new medications and animals alter their behavior to the changing environment. The changes that occur are often evident.

But it wasn't until the late-1980s that biologists realized that natural selection could be seen in action, as well. The key is that different traits have different rates of survival and reproduction (differential fitness) and are transferred from one generation to the next.

In the past, if one particular allele--the genetic sequence that defines color in a group of interbreeding species, it could quickly become more prevalent than the other alleles. Over time, that would mean that 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.

It is easier to track evolutionary change when a species, such as bacteria, has a rapid generation turnover. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain; samples of each population are taken on a regular basis, and over 50,000 generations have now passed.

Lenski's work has demonstrated that a mutation can profoundly alter the rate at which a population reproduces--and so, the rate at which it alters. It also shows evolution takes time, which is difficult for some to accept.

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

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