The Academy's Evolution Site

Biological evolution is a central concept in biology. The Academies are committed to helping those interested in the sciences learn about the theory of evolution and how it is permeated in all areas of scientific research.

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

Tree of Life

The Tree of Life, 무료 에볼루션 에볼루션 블랙잭 (from this source) an ancient symbol, represents the interconnectedness of all life. It is a symbol of love and harmony in a variety of cultures. It has many practical applications as well, such as providing a framework for understanding the evolution of species and how they respond to changing environmental conditions.

Early attempts to describe the world of biology were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which relied on sampling of different parts of living organisms or 에볼루션 바카라 무료체험 small DNA fragments, significantly expanded the diversity that could be represented in a tree of life2. However the trees are mostly made up of eukaryotes. Bacterial diversity remains vastly underrepresented3,4.

Genetic techniques have significantly expanded our ability to represent the Tree of Life by circumventing the requirement for direct observation and experimentation. We can construct trees by using molecular methods such as the small subunit ribosomal gene.

Despite the rapid growth of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is especially the case for microorganisms which are difficult to cultivate, and are usually found in a single specimen5. A recent analysis of all genomes has produced a rough draft of the Tree of Life. This includes a large number of bacteria, archaea and other organisms that haven't yet been isolated, or whose diversity has not been thoroughly understood6.

The expanded Tree of Life can be used to determine the diversity of a particular area and determine if specific habitats require special protection. The information can be used in a range of ways, from identifying the most effective medicines to combating disease to improving the quality of crops. The information is also incredibly beneficial for 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 human-induced change. While funds to protect biodiversity are essential, the best method to preserve the biodiversity of the world is to equip the people of developing nations with the knowledge they need to act locally and support conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, shows the relationships between groups of organisms. Scientists can build a phylogenetic chart that shows the evolutionary relationship of taxonomic groups based on molecular data and morphological differences or similarities. The concept of phylogeny is fundamental to understanding biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 Determines the relationship between organisms with similar traits and evolved from an ancestor that shared traits. These shared traits could be analogous, or homologous. Homologous traits are the same in their evolutionary journey. Analogous traits may look similar, but they do not share the same origins. Scientists group similar traits together into a grouping referred to as a the clade. All members of a clade have a common characteristic, like amniotic egg production. They all evolved from an ancestor 무료 에볼루션 that had these eggs. The clades then join to form a phylogenetic branch that can determine which organisms have the closest relationship.

For a more precise and accurate phylogenetic tree scientists rely on molecular information from DNA or RNA to establish the relationships between organisms. This information is more precise and provides evidence of the evolution of an organism. Researchers can utilize Molecular Data to determine the age of evolution of living organisms and discover how many species have the same ancestor.

The phylogenetic relationship can be affected by a variety of factors such as the phenomenon of phenotypicplasticity. This is a type behavior that alters in response to specific environmental conditions. This can cause a trait to appear more similar in one species than other species, which can obscure the phylogenetic signal. This problem can be mitigated by using cladistics, which is a a combination of homologous and analogous features in the tree.

In addition, phylogenetics can aid in predicting the time and pace of speciation. This information can assist conservation biologists decide the species they should safeguard from extinction. In the end, it's the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced.

Evolutionary Theory

The main idea behind evolution is that organisms acquire different features over time as a result of their interactions with their surroundings. 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 could evolve according to its own needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of traits can cause changes that are passed on to the

In the 1930s and 1940s, theories from various fields, including genetics, natural selection and particulate inheritance -- came together to create the modern synthesis of evolutionary theory which explains how evolution occurs through the variations of genes within a population and how those variants change over time as a result of natural selection. This model, called genetic drift or mutation, gene flow and sexual selection, 에볼루션 코리아 is a cornerstone of modern evolutionary biology and can be mathematically described.

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

Students can better understand the concept of phylogeny by using evolutionary thinking into all areas of biology. A recent study by Grunspan and colleagues, for instance demonstrated that teaching about the evidence for evolution increased students' acceptance of evolution in a college biology course. To learn more about how to teach about evolution, read The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily A Framework for Infusing the Concept of Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution by studying fossils, comparing species and studying living organisms. Evolution is not a past event, but a process that continues today. Viruses evolve to stay away from new drugs and bacteria evolve to resist antibiotics. Animals adapt their behavior in the wake of a changing world. The changes that result are often easy to see.

But it wasn't until the late 1980s that biologists realized that natural selection can be seen in action, as well. The key is the fact that different traits can confer an individual rate of survival as well as reproduction, and may be passed down from one generation to the next.

In the past, if one particular allele--the genetic sequence that determines coloration--appeared in a population of interbreeding organisms, 에볼루션카지노사이트 it could rapidly become more common than other alleles. In time, this could 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.

The ability to observe evolutionary change is easier when a particular species has a rapid turnover of its generation like bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain. samples of each are taken every day and over 500.000 generations have been observed.

Lenski's research has revealed that mutations can drastically alter the rate at which a population reproduces and, consequently the rate at which it alters. It also demonstrates that evolution takes time, a fact that is difficult for some to accept.

Another example of microevolution is how mosquito genes that are resistant to pesticides are more prevalent in populations where insecticides are employed. That's because the use of pesticides creates a selective pressure that favors people who have resistant genotypes.

The rapidity of evolution has led to a greater appreciation of its importance, especially in a world which is largely shaped by human activities. This includes climate change, pollution, and habitat loss, which prevents many species from adapting. Understanding the evolution process can help us make better choices about the future of our planet, and the life of its inhabitants.