The 12 Best Evolution Site Accounts To Follow On Twitter
The Academy's Evolution Site
Biological evolution is a central concept in biology. The Academies are committed to helping those interested in science to comprehend the evolution theory and how it can be applied throughout all fields of scientific research.
This site offers a variety of tools for students, teachers and general readers of evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.
Tree of Life
The Tree of Life is an ancient symbol that symbolizes the interconnectedness of life. It is seen in a variety of religions and cultures as a symbol of unity and love. It also has important practical applications, such as providing a framework to understand the history of species and how they respond to changing environmental conditions.
Early approaches to depicting the world of biology focused on separating organisms into distinct categories which had been identified by their physical and metabolic characteristics1. These methods, which rely on the sampling of various parts of living organisms or short DNA fragments, greatly increased the variety of organisms that could be included in a tree of life2. However, these trees are largely composed of eukaryotes; bacterial diversity is not represented in a large way3,4.
By avoiding the necessity for direct experimentation and observation, genetic techniques have enabled us to depict the Tree of Life in a more precise manner. Particularly, molecular techniques enable us to create trees using sequenced markers, such as the small subunit ribosomal gene.
Despite the dramatic expansion of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is especially true of microorganisms, which are difficult to cultivate and are typically only represented 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 their diversity is not thoroughly understood6.
The expanded Tree of Life can be used to evaluate the biodiversity of a particular area and determine if particular habitats need special protection. The information can be used in a range of ways, from identifying the most effective treatments to fight disease to improving the quality of crops. This information is also extremely valuable in conservation efforts. It can aid biologists in identifying areas that are likely to be home to cryptic species, which may perform important metabolic functions, and could be susceptible to the effects of human activity. While funds to protect biodiversity are crucial, ultimately the best way to preserve the world's biodiversity is for 에볼루션게이밍 more people in developing countries to be equipped with the knowledge to take action locally to encourage conservation from within.
Phylogeny
A phylogeny, also called an evolutionary tree, illustrates the connections between groups of organisms. By using molecular information similarities and differences in morphology, or ontogeny (the process of the development of an organism) scientists can construct a phylogenetic tree that illustrates the evolutionary relationships between taxonomic groups. 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 that share similar traits that evolved from common ancestors. These shared traits could be analogous, or homologous. Homologous traits are similar in terms of their evolutionary path. Analogous traits might appear similar but they don't share the same origins. Scientists group similar traits together into a grouping known as a clade. All members of a clade have a common trait, such as amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree is built by connecting the clades to determine the organisms which are the closest to one another.
Scientists make use of DNA or RNA molecular data to construct a phylogenetic graph that is more accurate and precise. This information is more precise than morphological information and gives evidence of the evolutionary background of an organism or group. The use of molecular data lets researchers identify the number of species who share the same ancestor and estimate their evolutionary age.
Phylogenetic relationships can be affected by a number of factors such as phenotypicplasticity. This is a type behavior that alters in response to particular environmental conditions. This can cause a characteristic to appear more similar in one species than another, obscuring the phylogenetic signal. This problem can be mitigated by using cladistics, which is a a combination of homologous and analogous features in the tree.
Furthermore, phylogenetics may help predict the length and speed of speciation. This information can aid conservation biologists in making decisions about which species to protect from the threat of extinction. It is ultimately the preservation of phylogenetic diversity that will result in 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 environments. 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 envisioned an organism developing slowly in accordance with its requirements, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that could be passed onto offspring.
In the 1930s & 1940s, concepts from various areas, including genetics, natural selection and particulate inheritance, came together to create a modern theorizing of evolution. This describes how evolution is triggered by the variation in genes within a population and how these variations change with time due to natural selection. This model, which encompasses genetic drift, mutations as well as gene flow and sexual selection is mathematically described mathematically.
Recent discoveries in the field of evolutionary developmental biology have revealed that variation can be introduced into a species through mutation, genetic drift, 에볼루션 바카라 사이트 and reshuffling of genes in sexual reproduction, and also by migration between populations. These processes, along with others such as directionally-selected selection and erosion of genes (changes in the frequency of genotypes over time) can result in evolution. Evolution is defined as changes in the genome over time, as well as changes in phenotype (the expression of genotypes within individuals).
Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking in all areas of biology. In a recent study conducted by Grunspan and colleagues. It was found that teaching students about the evidence for evolution increased their understanding of evolution during an undergraduate biology course. For more information on how to teach about evolution, please see The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily A Framework for 에볼루션 슬롯게임 Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have studied evolution through looking back in the past, analyzing fossils and comparing species. They also study living organisms. Evolution is not a distant event; it is a process that continues today. Viruses evolve to stay away from new drugs and bacteria evolve to resist antibiotics. Animals adapt their behavior because of a changing world. The resulting changes are often easy to see.
However, it wasn't until late 1980s that biologists realized that natural selection can be observed in action as well. The main reason is that different traits confer a different rate of survival as well as reproduction, and may be passed down from one generation to the next.
In the past when one particular allele, the genetic sequence that controls coloration - was present in a population of interbreeding species, it could rapidly become more common than other alleles. In time, this could mean that the number of black moths in 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 evolution when the species, like bacteria, has a high generation turnover. 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 on a regular basis, and 에볼루션사이트 over 500.000 generations have passed.
Lenski's research has shown that mutations can drastically alter the speed at which a population reproduces and, consequently, the rate at which it evolves. It also shows evolution takes time, something that is hard for 에볼루션 사이트 some to accept.
Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more prevalent in populations where insecticides have been used. This is due to pesticides causing a selective pressure which favors those who have resistant genotypes.
The rapidity of evolution has led to a growing recognition of its importance especially in a planet that is largely shaped by human activity. This includes climate change, pollution, and habitat loss that hinders many species from adapting. Understanding evolution will aid you in making better decisions about the future of the planet and its inhabitants.
