15 Reasons To Not Overlook Evolution Site
The Academy's Evolution Site
Biological evolution is a central concept 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 permeates all areas of scientific research.
This site provides a wide range of sources for students, teachers, and general readers on evolution. It has important 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 a symbol of love and harmony in a variety of cultures. It also has practical applications, like providing a framework to understand the evolution of species and how they react to changing environmental conditions.
The earliest attempts to depict the world of biology focused on separating organisms into distinct categories which were distinguished by their physical and metabolic characteristics1. These methods, which rely 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 the trees are mostly composed of eukaryotes; bacterial diversity is still largely unrepresented3,4.
In avoiding the necessity of direct observation and experimentation genetic techniques have allowed us to represent the Tree of Life in a more precise manner. We can create trees using molecular methods, such as the small-subunit ribosomal gene.
The Tree of Life has been greatly expanded thanks to genome sequencing. However there is sneak a peek at this web-site of diversity to be discovered. This is particularly true of microorganisms, which are difficult to cultivate and are usually only present in a single specimen5. A recent analysis of all genomes resulted in a rough draft of a Tree of Life. This includes a wide range of archaea, bacteria, and other organisms that haven't yet been isolated or their diversity is not fully understood6.
The expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, which can help to determine if certain habitats require special protection. This information can be used in a variety of ways, from identifying new medicines to combating disease to enhancing the quality of crops. This information is also valuable to conservation efforts. It can help biologists identify areas that are most likely to be home to cryptic species, which may have important metabolic functions, and could be susceptible to human-induced change. While funds to protect biodiversity are crucial, ultimately the best way to ensure the preservation of biodiversity around the world is for more people 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, reveals the relationships between groups of organisms. Using molecular data similarities and differences in morphology, or ontogeny (the course of development of an organism) scientists can create a phylogenetic tree that illustrates the evolution of taxonomic groups. Phylogeny is essential in understanding biodiversity, evolution and genetics.
A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms that have similar characteristics and have evolved from a common ancestor. These shared traits are either homologous or analogous. Homologous traits are identical in their underlying evolutionary path, while analogous traits look like they do, but don't have the identical origins. Scientists organize similar traits into a grouping referred to as a the clade. Every organism in a group share a characteristic, for example, amniotic egg production. They all evolved from an ancestor with these eggs. A phylogenetic tree is then constructed by connecting the clades to determine the organisms which are the closest to one another.
Scientists utilize DNA or RNA molecular information to create a phylogenetic chart that is more precise and precise. This information is more precise and gives evidence of the evolution history of an organism. Researchers can utilize Molecular Data to estimate the evolutionary age of living organisms and discover how many organisms have an ancestor common to all.
The phylogenetic relationships of organisms are influenced by many factors, including phenotypic plasticity a type of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more similar to a species than another and obscure the phylogenetic signals. However, this issue can be solved through the use of methods such as cladistics that combine analogous and homologous features into the tree.
In addition, phylogenetics helps determine the duration and rate of speciation. This information can aid conservation biologists in deciding which species to save from disappearance. In the end, it's the preservation of phylogenetic diversity that will create a complete and balanced ecosystem.
Evolutionary Theory
The fundamental concept of evolution is that organisms develop different features over time due to their interactions with their environments. Many scientists have developed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism could develop according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the use or non-use of certain traits can result in changes that are passed on to the next generation.
In the 1930s & 1940s, theories from various fields, such as natural selection, genetics & particulate inheritance, were brought together to form a contemporary synthesis of evolution theory. This explains how evolution occurs by the variation in genes within the population and how these variants change over time as a result of natural selection. This model, called genetic drift or mutation, gene flow, and sexual selection, is a cornerstone of the current evolutionary biology and can be mathematically described.
Recent advances in the field of evolutionary developmental biology have revealed the ways in which variation can be introduced to a species through genetic drift, mutations, reshuffling genes during sexual reproduction and migration between populations. These processes, as well as others such as directionally-selected selection and erosion of genes (changes in the frequency of genotypes over time) can lead to evolution. Evolution is defined as changes in the genome over time, as well as changes in phenotype (the expression of genotypes in an individual).
Students can better understand the concept of phylogeny through incorporating evolutionary thinking in all areas of biology. A recent study conducted by Grunspan and colleagues, for instance, showed that teaching about the evidence for evolution increased students' acceptance of evolution in a college biology class. To learn more about how to teach about evolution, please 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 by looking in the past, studying fossils, and comparing species. They also study living organisms. Evolution isn't a flims event; it is a process that continues today. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals adapt their behavior in the wake of a changing world. The changes that occur are often apparent.
It wasn't until late 1980s when biologists began to realize that natural selection was in action. The key to this is that different traits result in an individual rate of survival and reproduction, and can be passed on from one generation to another.
In the past, when one particular allele--the genetic sequence that controls coloration - was present in a population of interbreeding organisms, it could quickly become more prevalent than all 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.
The ability to observe evolutionary change is easier when a particular species has a rapid turnover of its generation, as with bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that are descended from a single strain. Samples from each population were taken regularly, and more than 50,000 generations of E.coli have passed.
Lenski's research has shown that a mutation can dramatically alter the speed at which a population reproduces--and so, the rate at which it changes. It also shows that evolution takes time, which is hard for some to accept.
Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides have been used. Pesticides create an enticement that favors those who have resistant genotypes.
The rapidity of evolution has led to a greater appreciation of its importance, especially in a world which is largely shaped by human activities. This includes climate change, pollution, and habitat loss that prevents 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.