The Academy's Evolution Site

Biological evolution is a central concept in biology. The Academies are involved in helping those who are interested in science to comprehend the evolution theory and how it is permeated in all areas of scientific research.

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

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of life. It is an emblem of love and harmony in a variety of cultures. It can be used in many practical ways as well, such as providing a framework to understand the history of species and how they respond to changes in environmental conditions.

The earliest attempts to depict the biological world focused on separating species into distinct categories that were distinguished by their physical and metabolic characteristics1. These methods depend on the sampling of different parts of organisms or short DNA fragments, have significantly increased the diversity of a Tree of Life2. However these trees are mainly made up of eukaryotes. Bacterial diversity is not represented in a large way3,4.

Genetic techniques have greatly broadened our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. Trees can be constructed using molecular techniques like the small-subunit ribosomal gene.

The Tree of Life has been significantly expanded by genome sequencing. However there is still a lot of biodiversity to be discovered. This is particularly the case for microorganisms which are difficult to cultivate and which are usually only present in a single sample5. A recent analysis of all genomes resulted in an initial draft of a Tree of Life. This includes a variety 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 can be used to evaluate the biodiversity of a particular area and determine if specific habitats require special protection. This information can be utilized in many ways, including finding new drugs, battling diseases and improving the quality of crops. The information is also beneficial in conservation efforts. It can aid biologists in identifying the areas that are most likely to contain cryptic species with potentially significant metabolic functions that could be vulnerable to anthropogenic change. While funds to protect biodiversity are important, the best method to protect the world's biodiversity is to empower more people in developing countries with the necessary knowledge to act locally and support conservation.

Phylogeny

A phylogeny (also called an evolutionary tree) depicts the relationships between different organisms. By using molecular information similarities and differences in morphology, or 에볼루션게이밍 ontogeny (the process of the developmhe tree.

In addition, phylogenetics can help predict the length and speed of speciation. This information can assist conservation biologists in making choices about which species to safeguard from extinction. In the end, it's the preservation of phylogenetic diversity which will lead to an ecologically balanced and complete ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms acquire distinct characteristics over time due to their interactions with their surroundings. Many scientists have developed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could evolve according to its own requirements and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern taxonomy system that is hierarchical as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of certain traits can result in changes that are passed on to the next generation.

In the 1930s and 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance, were brought together to form a modern synthesis of evolution theory. This describes how evolution occurs by the variations in genes within a population and how these variations change with time due to natural selection. This model, which encompasses mutations, genetic drift, gene flow and sexual selection is mathematically described.

Recent discoveries in the field of evolutionary developmental biology have revealed that variation can be introduced into a species through mutation, genetic drift and reshuffling of genes during sexual reproduction, as well as by migration between populations. These processes, as well as others like directional selection and 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 에볼루션 바카라 사이트 also the change in phenotype over time (the expression of that genotype in the individual).

Students can better understand the concept of phylogeny through incorporating evolutionary thinking throughout all aspects of biology. A recent study by Grunspan and colleagues, for instance demonstrated that teaching about the evidence supporting evolution helped students accept the concept of evolution in a college-level biology course. For more details about how to teach evolution, see The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily: a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Scientists have traditionally studied evolution through looking back in the past, analyzing fossils and comparing species. They also study living organisms. But evolution isn't a thing that occurred in the past; it's an ongoing process, that is taking place today. Viruses reinvent themselves to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior as a result of a changing world. The results are often visible.

However, it wasn't until late 1980s that biologists realized that natural selection can be observed in action as well. The reason is that different traits have different rates of survival and reproduction (differential fitness), and 에볼루션 블랙잭 can be passed from one generation to the next.

In the past, when one particular allele, the genetic sequence that defines color 무료에볼루션 in a group of interbreeding organisms, it could quickly become more common than the other alleles. In time, this could 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 easier when a particular species has a fast generation turnover, as with bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples from each population are taken on a regular basis, and over 500.000 generations have passed.

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

Another example of microevolution is how mosquito genes that are resistant to pesticides show up more often in areas where insecticides are employed. This is due to the fact that the use of pesticides creates a selective pressure that favors those who have resistant genotypes.

The rapidity of evolution has led to a greater recognition of its importance especially in a planet that is largely shaped by human activity. This includes climate change, pollution, and habitat loss that prevents many species from adapting. Understanding the evolution process can assist you in making better choices about the future of the planet and its inhabitants.