The Academy's Evolution Site

Biological evolution is a central concept in biology. The Academies have been for a long time involved in helping those interested in science comprehend the concept of evolution and how it affects all areas of scientific exploration.

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

Tree of Life

The Tree of Life, 에볼루션코리아 an ancient symbol, symbolizes the interconnectedness of all life. It is an emblem of love and unity in many cultures. It also has practical applications, such as providing a framework to understand the evolution of species and how they react to changes in the environment.

The earliest attempts to depict the world of biology focused on separating species into distinct categories that were distinguished by their physical and metabolic characteristics1. These methods are based on the collection of various parts of organisms or short DNA fragments, have greatly increased the diversity of a Tree of Life2. These trees are largely composed by eukaryotes, and bacteria are largely underrepresented3,4.

By avoiding the need for direct experimentation and observation, genetic techniques have enabled us to represent the Tree of Life in a more precise way. Particularly, molecular methods enable us to create trees using sequenced markers such as the small subunit ribosomal RNA gene.

The Tree of Life has been dramatically expanded through genome sequencing. However there is a lot of biodiversity to be discovered. This is especially the case for microorganisms which are difficult to cultivate, and which are usually only found in one sample5. A recent analysis of all genomes that are known has produced a rough draft of the Tree of Life, including many archaea and bacteria that have not been isolated and their diversity is not fully understood6.

This expanded Tree of Life is particularly useful for assessing the biodiversity of an area, which can help to determine if certain habitats require special protection. This information can be used in many ways, including finding new drugs, 에볼루션 게이밍 fighting diseases and improving crops. The information is also incredibly beneficial in conservation efforts. It helps biologists discover areas most likely to be home to cryptic species, which could have vital metabolic functions and 에볼루션 바카라 체험 be vulnerable to human-induced change. Although funding to safeguard biodiversity are vital however, the most effective method to preserve the world's biodiversity is for more people living in developing countries to be empowered with the knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the relationships between various groups of organisms. By using molecular information similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree that illustrates the evolutionary relationships between taxonomic groups. The role of phylogeny is crucial in understanding genetics, biodiversity and evolution.

A basic phylogenetic tree (see Figure PageIndex 10 Identifies the relationships between organisms with similar traits and have evolved from an ancestor with common traits. These shared traits can be either homologous or analogous. Homologous traits are the same in terms of their evolutionary journey. Analogous traits could appear like they are, but they do not share the same origins. Scientists organize similar traits into a grouping known as a the clade. For instance, all of the species in a clade share the trait of having amniotic eggs and evolved from a common ancestor who had eggs. The clades are then linked to form a phylogenetic branch that can determine which organisms have the closest connection to each other.

For a more precise and 에볼루션 게이밍 accurate phylogenetic tree scientists make use of molecular data from DNA or RNA to identify the connections between organisms. This information is more precise and provides evidence of the evolution of an organism. Molecular data allows researchers to identify the number of organisms that have the same ancestor and estimate their evolutionary age.

The phylogenetic relationships between organisms can be influenced by several factors including phenotypic plasticity, a kind of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar to one species than another, 에볼루션 무료 바카라 clouding the phylogenetic signal. However, this problem can be solved through the use of methods such as cladistics which include a mix of analogous and homologous features into the tree.

Additionally, phylogenetics can help determine the duration and rate at which speciation takes place. This information can aid conservation biologists to make decisions about which species to protect from extinction. Ultimately, it is the preservation of phylogenetic diversity which will create an ecosystem that is complete and balanced.

Evolutionary Theory

The fundamental concept in evolution is that organisms alter over time because of their interactions with their environment. Many scientists have come up with theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that a living thing would evolve according to its own needs and needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or non-use of certain traits can result in changes that can be passed on to future generations.

In the 1930s and 1940s, theories from various fields, including genetics, natural selection and particulate inheritance, were brought together to form a contemporary evolutionary theory. This explains how evolution occurs by the variation in genes within the population and how these variations alter over time due to natural selection. This model, which incorporates genetic drift, mutations as well as gene flow and sexual selection can be mathematically described.

Recent discoveries in evolutionary developmental biology have demonstrated the ways in which variation can be introduced to a species by mutations, genetic drift or reshuffling of genes in sexual reproduction and migration between populations. These processes, along with others such as directional selection or genetic erosion (changes in the frequency of a genotype over time) can lead to evolution which is defined by change in the genome of the species over time and also the change in phenotype as time passes (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 areas of biology. In a recent study conducted by Grunspan and co., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during the course of a college biology. To learn more about how to teach about evolution, look up The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Scientists have studied evolution through looking back in the past, studying fossils, and comparing species. They also observe living organisms. Evolution is not a past moment; it is a process that continues today. The virus reinvents itself to avoid new drugs and bacteria evolve to resist antibiotics. Animals adapt their behavior because of a changing environment. The resulting changes are often visible.

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

In the past when one particular allele, the genetic sequence that determines coloration--appeared in a group of interbreeding organisms, it might quickly become more common than the other alleles. In time, this could mean that the number of moths sporting black pigmentation in a population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

Monitoring evolutionary changes in action is much easier when a species has a fast 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 from each population are taken every day, and over fifty thousand 에볼루션바카라사이트 generations have passed.

Lenski's research has revealed that a mutation can dramatically alter the speed at which a population reproduces and, consequently the rate at which it evolves. It also shows that evolution takes time--a fact that many are unable to accept.

Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more common in populations where insecticides have been used. This is because the use of pesticides causes a selective pressure that favors those with resistant genotypes.

The speed at which evolution takes place has led to an increasing awareness of its significance in a world that is shaped by human activity--including climate change, pollution, and the loss of habitats that prevent many species from adjusting. Understanding evolution will help you make better decisions regarding the future of the planet and its inhabitants.