How To Create An Awesome Instagram Video About Evolution Site
The Academy's Evolution Site
Biology is a key concept in biology. The Academies are committed to helping those who are interested in science to understand evolution theory and how it is permeated in all areas of scientific research.
This site provides a range of resources for students, teachers and general readers of evolution. It contains important video clips from NOVA and WGBH's science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is used in many religions and cultures as symbolizing unity and love. It can be used in many practical ways as well, including providing a framework for understanding the history of species and how they respond to changes in environmental conditions.
The first attempts at depicting the world of biology focused on separating species into distinct categories that were identified by their physical and metabolic characteristics1. These methods, based on sampling of different parts of living organisms or on sequences of short fragments of their DNA, greatly increased the variety of organisms that could be included in a tree of life2. However these trees are mainly composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4.
By avoiding the need for direct observation and experimentation genetic techniques have enabled us to represent the Tree of Life in a much more accurate way. In particular, molecular methods allow us to construct trees by using sequenced markers, such as the small subunit of ribosomal RNA gene.
Despite the dramatic expansion of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is especially relevant to microorganisms that are difficult to cultivate, and are usually found in one sample5. A recent analysis of all known genomes has produced a rough draft of the Tree of Life, including many archaea and bacteria that have not been isolated and whose diversity is poorly understood6.
This expanded Tree of Life is particularly useful in assessing the diversity of an area, assisting to determine whether specific habitats require protection. The information can be used in a variety of ways, from identifying new medicines to combating disease to improving crop yields. This information is also extremely valuable to conservation efforts. It helps biologists determine those areas that are most likely contain cryptic species that could have important metabolic functions that could be at risk of anthropogenic changes. Although funds 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 equipped with the knowledge to act locally in order to promote conservation from within.
Phylogeny
A phylogeny (also known as an evolutionary tree) illustrates the relationship between species. 에볼루션 바카라 무료체험 can build a phylogenetic chart that shows the evolutionary relationships between taxonomic categories using molecular information and morphological similarities or differences. The phylogeny of a tree plays an important role in understanding biodiversity, genetics and evolution.
A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms with similar traits and evolved from a common ancestor. These shared traits may be analogous, or homologous. Homologous traits are identical in their underlying evolutionary path while analogous traits appear similar, but do not share the identical origins. Scientists group similar traits into a grouping known as a Clade. For instance, all of the organisms in a clade share the characteristic of having amniotic eggs. They evolved from a common ancestor who had eggs. The clades are then linked to create a phylogenetic tree to determine the organisms with the closest relationship to.
Scientists use molecular DNA or RNA data to construct a phylogenetic graph that is more accurate and detailed. This data is more precise than the morphological data and provides evidence of the evolution history of an organism or group. Researchers can use Molecular Data to estimate the age of evolution of organisms and identify how many organisms share an ancestor common to all.
The phylogenetic relationship can be affected by a variety of factors, including the phenomenon of phenotypicplasticity. This is a type behavior that alters as a result of unique environmental conditions. This can cause a trait to appear more similar to one species than another which can obscure the phylogenetic signal. However, this issue can be solved through the use of techniques like cladistics, which include a mix of analogous and homologous features into the tree.
In addition, phylogenetics helps predict the duration and rate at which speciation takes place. This information can aid conservation biologists in deciding which species to save from the threat of extinction. It is ultimately the preservation of phylogenetic diversity that will create an ecologically balanced and complete ecosystem.
Evolutionary Theory
The central theme in evolution is that organisms change over time due to their interactions with their environment. Many scientists have developed theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism would evolve according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived 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 a variety of fields -- including genetics, natural selection and particulate inheritance--came together to create the modern synthesis of evolutionary theory that explains how evolution occurs through the variation of genes within a population and how those variations change over time as a result of natural selection. This model, known as genetic drift or mutation, gene flow and sexual selection, is the foundation of the current evolutionary biology and is mathematically described.
Recent advances in evolutionary developmental biology have shown the ways in which 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, along with others such as directional selection or genetic erosion (changes in the frequency of the genotype over time) can result in evolution, which is defined by change in the genome of the species over time, and also by changes in phenotype as time passes (the expression of that genotype in an individual).
Incorporating evolutionary thinking into all aspects of biology education could increase students' understanding of phylogeny and evolutionary. In a study by Grunspan and co. It was demonstrated that teaching students about the evidence for evolution increased their understanding of evolution in a college-level course in biology. To find out more about how to teach about evolution, see The Evolutionary Potential in All Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have traditionally studied evolution by looking in the past, studying fossils, and comparing species. They also study living organisms. But evolution isn't just something that occurred in the past; it's an ongoing process, that is taking place in the present. Bacteria transform and resist antibiotics, viruses re-invent themselves and escape new drugs and animals change their behavior to the changing climate. The results are often visible.
It wasn't until the 1980s when biologists began to realize that natural selection was also in play. The key is that different characteristics result in different rates of survival and reproduction (differential fitness) and can be passed from one generation to the next.
In the past, if a certain allele - the genetic sequence that determines colour was found in a group of organisms that interbred, it might become more common than any other allele. Over time, this would mean that the number of moths with black pigmentation in a population may 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 easier when a particular species has a rapid turnover of its generation such as bacteria. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. Coli that descended from a single strain; samples of each population are taken every day and over 50,000 generations have now been observed.
Lenski's research has demonstrated that mutations can alter the rate of change and the rate of a population's reproduction. It also demonstrates that evolution takes time, something that is difficult for some to accept.
Microevolution can be observed in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides are used. This is due to pesticides causing a selective pressure which favors individuals who have resistant genotypes.
The rapidity of evolution has led to a growing awareness of its significance particularly in a world which is largely shaped by human activities. This includes pollution, climate change, and habitat loss that hinders many species from adapting. Understanding the evolution process will help us make better choices about the future of our planet, and the lives of its inhabitants.