The Academy's Evolution Site

Biology is one of the most central concepts 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 permeates all areas of scientific research.

This site offers a variety of resources for teachers, students and general readers of evolution. It contains the most important video clips from NOVA and the WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that symbolizes the interconnectedness of all life. It is a symbol of love and unity in many cultures. It also has many practical applications, such as providing a framework to understand the evolution of species and how they respond to changing environmental conditions.

The earliest attempts to depict the biological world focused on categorizing species into distinct categories that were identified by their physical and metabolic characteristics1. These methods, 에볼루션 사이트 which rely on the collection of various parts of organisms or short DNA fragments, have significantly increased the diversity of a Tree of Life2. The trees are mostly composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4.

Genetic techniques have greatly broadened our ability to depict the Tree of Life by circumventing the requirement for 에볼루션 direct observation and experimentation. We can create trees by using molecular methods like the small-subunit ribosomal gene.

The Tree of Life has been significantly expanded by genome sequencing. However, there is still much biodiversity to be discovered. This is particularly relevant to microorganisms that are difficult to cultivate, and which are usually only found in a single specimen5. Recent analysis of all genomes has produced an initial draft of a Tree of Life. This includes a wide range of archaea, bacteria, and other organisms that haven't yet been identified or the diversity of which is not well understood6.

The expanded Tree of Life is particularly useful in assessing the diversity of an area, which can help to determine if certain habitats require protection. The information is useful in a variety of ways, including finding new drugs, fighting diseases and improving crops. The information is also incredibly useful for conservation efforts. It can help biologists identify the areas that are most likely to contain cryptic species that could have important metabolic functions that could be vulnerable to anthropogenic change. While funds to safeguard biodiversity are vital but the most effective way to ensure the preservation of biodiversity around the world is for more people living 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, shows the relationships between various groups of organisms. Utilizing molecular data, morphological similarities and differences, or ontogeny (the process of the development of an organism), scientists can build an phylogenetic tree that demonstrates the evolution of taxonomic categories. The concept of phylogeny is fundamental to 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 ancestors. These shared traits may be analogous or homologous. Homologous traits are identical in their evolutionary origins while analogous traits appear similar but do not have the same origins. Scientists put similar traits into a grouping called a clade. For instance, all of the organisms in a clade share the characteristic of having amniotic egg and evolved from a common ancestor 에볼루션 코리아 that had eggs. A phylogenetic tree is then built by connecting the clades to identify the species who are the closest to each other.

For a more detailed 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 history of an organism. Researchers can use Molecular Data to calculate the evolutionary age of organisms and determine how many species share a common ancestor.

Phylogenetic relationships can be affected by a number of factors such as the phenotypic plasticity. This is a type of behaviour that can change due to unique environmental conditions. This can cause a trait to appear more similar in one species than another, clouding the phylogenetic signal. However, this problem can be solved through the use of techniques such as cladistics that combine homologous and analogous features into the tree.

Additionally, phylogenetics aids predict the duration and rate at which speciation takes place. This information can aid conservation biologists in deciding which species to save from extinction. In the end, it is the conservation of phylogenetic diversity which will create an ecosystem that is balanced and complete.

Evolutionary Theory

The central theme in evolution is that organisms change over time as a result of their interactions with their environment. Several theories of evolutionary change have been proposed by a variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly in accordance with its requirements and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits causes changes that could be passed on to offspring.

In the 1930s and 1940s, theories from various fields, including natural selection, genetics, and particulate inheritance - came together to form the modern evolutionary theory synthesis which explains how evolution is triggered by the variations of genes within a population, and how those variations change in time as a result of natural selection. This model, which encompasses mutations, genetic drift in gene flow, and sexual selection can be mathematically described mathematically.

Recent discoveries in the field of evolutionary developmental biology have demonstrated that variation can be introduced into a species through mutation, genetic drift, and reshuffling of genes in sexual reproduction, and also through the movement of populations. These processes, as well as others such as directional selection or genetic erosion (changes in the frequency of an individual's genotype over time), can lead to evolution that is defined as changes in the genome of the species over time, and the change in phenotype over time (the expression of the genotype in an individual).

Students can gain a better understanding of the concept of phylogeny by using evolutionary thinking into all aspects of biology. In a study by Grunspan and colleagues., it was shown 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, please read The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have studied evolution by looking in the past--analyzing fossils and comparing species. They also observe living organisms. But evolution isn't just something that happened in the past, it's an ongoing process that is happening today. Bacteria transform and resist antibiotics, viruses reinvent themselves and escape new drugs and 에볼루션 무료체험 - Http://120.202.38.15:3000/evolutionkr0087 - animals alter their behavior in response to a changing planet. The resulting changes are often easy to see.

However, it wasn't until late 1980s that biologists understood that natural selection can be observed in action as well. The main reason is that different traits can confer the ability to survive at different rates and reproduction, and can be passed on from one generation to another.

In the past, if one particular allele--the genetic sequence that determines coloration--appeared in a population of interbreeding organisms, it could quickly become more common than all other alleles. Over time, that would mean that the number of black moths in a population could 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 fast generation turnover like bacteria. 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 every day, and over 50,000 generations have now passed.

Lenski's work has demonstrated that a mutation can dramatically alter the efficiency with which a population reproduces--and so the rate at which it alters. It also shows that evolution is slow-moving, a fact that some are unable 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 due to pesticides causing an enticement that favors individuals who have resistant genotypes.

The rapidity of evolution has led to a growing awareness of its significance particularly in a world that is largely shaped by human activity. This includes the effects of climate change, pollution and habitat loss that prevents many species from adapting. Understanding evolution will assist you in making better choices about the future of our planet and its inhabitants.