Learn To Communicate Evolution Site To Your Boss
The Academy's Evolution Site
The concept of biological evolution is among the most fundamental concepts in biology. The Academies have been active for a long time in helping people who are interested in science comprehend the theory of evolution and how it affects every area of scientific inquiry.
This site provides a range of sources for students, teachers and general readers of evolution. It has key video clips from NOVA and WGBH-produced science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is used in many cultures and spiritual beliefs as an emblem of unity and love. It has many practical applications in addition to providing a framework to understand the evolution of species and how they respond to changing environmental conditions.
Early attempts to represent the world of biology were founded on categorizing organisms on their physical and metabolic characteristics. These methods, based on sampling of different parts of living organisms, or small fragments of their DNA greatly increased the variety of organisms that could be included in a tree of life2. However these trees are mainly comprised of eukaryotes, and bacterial diversity is still largely unrepresented3,4.
Genetic techniques have greatly broadened our ability to depict the Tree of Life by circumventing the requirement for direct observation and experimentation. In particular, molecular methods allow us to build trees by using sequenced markers, such as the small subunit of ribosomal RNA gene.
Despite the rapid growth of the Tree of Life through genome sequencing, a large amount of biodiversity awaits discovery. This is particularly the case for microorganisms which are difficult to cultivate, and which are usually only present in a single sample5. Recent analysis of all genomes produced an unfinished draft of a Tree of Life. This includes a large number of archaea, bacteria, and other organisms that haven't yet been identified or their diversity is not well understood6.
The expanded Tree of Life can be used to evaluate the biodiversity of a specific area and determine if specific habitats need special protection. This information can be used in many ways, including finding new drugs, battling diseases and 에볼루션 코리아 슬롯게임; Www.v0795.Com, improving crops. This information is also beneficial in conservation efforts. It helps biologists discover areas that are most likely to be home to cryptic species, which may have important metabolic functions, and could be susceptible to changes caused by humans. While funds to safeguard biodiversity are vital but the most effective way to preserve the world's biodiversity is for more people living in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within.
Phylogeny
A phylogeny, also called an evolutionary tree, reveals the relationships between various groups of organisms. Scientists can create an phylogenetic chart which shows the evolutionary relationship of taxonomic categories using molecular information and morphological differences or similarities. Phylogeny is essential in understanding the evolution of biodiversity, evolution and genetics.
A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and have evolved from an ancestor that shared traits. These shared traits could be either homologous or analogous. Homologous traits are the same in their evolutionary paths. Analogous traits may look like they are but they don't share the same origins. Scientists group similar traits into a grouping referred to as a clade. For instance, all the organisms in a clade have the characteristic of having amniotic eggs and evolved from a common ancestor which had eggs. A phylogenetic tree is then constructed by connecting the clades to determine the organisms who are the closest to one another.
Scientists make use of DNA or RNA molecular information to build a phylogenetic chart which is more precise and detailed. This information is more precise than the morphological data and provides evidence of the evolution background of an organism or group. The use of molecular data lets researchers identify the number of species that share a common ancestor and to estimate their evolutionary age.
The phylogenetic relationships of a species can be affected by a number of factors, including the phenomenon of phenotypicplasticity. This is a type behavior that alters due to specific environmental conditions. This can cause a characteristic to appear more similar to one species than another, obscuring the phylogenetic signal. However, this problem can be solved through the use of methods like cladistics, which combine analogous and homologous features into the tree.
Additionally, phylogenetics can help determine the duration and speed at which speciation occurs. This information can assist conservation biologists in deciding which species to save from disappearance. In the end, it is the conservation of phylogenetic variety which will create an ecosystem that is balanced and complete.
Evolutionary Theory
The main idea behind 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 wide range of scientists, including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop gradually according to its requirements and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who developed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits can cause changes that could be passed onto offspring.
In the 1930s and 1940s, concepts from a variety of fields -- including genetics, natural selection, and particulate inheritance - came together to form the current evolutionary theory, which defines how evolution occurs through the variations of genes within a population, and how these variants change in time due to natural selection. This model, which is known as genetic drift or mutation, gene flow and sexual selection, is a cornerstone of the current evolutionary biology and can be mathematically explained.
Recent discoveries in evolutionary developmental biology have revealed how variation can be introduced to a species by mutations, genetic drift or reshuffling of genes in sexual reproduction and the movement between populations. These processes, as well as others such as directional selection and gene erosion (changes to the frequency of genotypes over time), can lead towards evolution. Evolution is defined as changes in the genome over time, as well as changes in the phenotype (the expression of genotypes within individuals).
Students can gain a better understanding of phylogeny by incorporating evolutionary thinking into all aspects of biology. A recent study by Grunspan and colleagues, for instance revealed that teaching students about the evidence that supports evolution increased students' understanding of evolution in a college-level biology class. To find out more about how to teach about evolution, please look up The Evolutionary Potential in all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Traditionally, scientists have studied evolution through looking back, 에볼루션 슬롯게임 studying fossils, comparing species and observing living organisms. Evolution is not a past event; it is a process that continues today. Bacteria mutate and resist antibiotics, viruses re-invent themselves and escape new drugs and animals change their behavior to the changing environment. The results are usually evident.
However, it wasn't until late 1980s that biologists understood that natural selection could be seen in action, as well. The reason is that different traits have different rates of survival and reproduction (differential fitness) and can be passed down from one generation to the next.
In the past, if one particular allele, the genetic sequence that controls coloration - was present in a group of interbreeding species, it could quickly become more common than all other alleles. As time passes, 에볼루션 바카라 무료체험 that could mean 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.
Monitoring evolutionary changes in action is much easier when a species has a rapid generation turnover like bacteria. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that descend from a single strain. Samples of each population have been taken frequently and more than 50,000 generations of E.coli have passed.
Lenski's work has shown that mutations can alter the rate of change and the efficiency of a population's reproduction. It also demonstrates that evolution takes time, something that is hard for some to accept.
Microevolution can be observed in the fact that mosquito genes for resistance to pesticides are more prevalent in areas that have used insecticides. Pesticides create an exclusive pressure that favors those with resistant genotypes.
The rapidity of evolution has led to a growing appreciation of its importance particularly in a world shaped largely by human activity. This includes pollution, climate change, and habitat loss that prevents many species from adapting. Understanding evolution can help us make better choices about the future of our planet and the life of its inhabitants.