15 Presents For Those Who Are The Evolution Site Lover In Your Life
The Academy's Evolution Site
Biology is a key concept in biology. The Academies have been active for a long time in helping those interested in science understand the theory of evolution and how it affects all areas of scientific exploration.
This site provides teachers, students and general readers with a wide range of learning resources on evolution. It has key video clips from NOVA and WGBH's science programs on DVD.
Tree of Life
The Tree of Life is an ancient symbol that represents the interconnectedness of life. It is used in many religions and cultures as symbolizing unity and love. It also has practical applications, like providing a framework to understand the evolution of species and how they react to changes in environmental conditions.
Early approaches to depicting the world of biology focused on categorizing organisms into distinct categories that were identified by their physical and metabolic characteristics1. These methods, which relied on the sampling of various parts of living organisms, or sequences of short fragments of their DNA significantly expanded the diversity that could be represented in a tree of life2. These trees are mostly populated by eukaryotes, and bacterial diversity is vastly underrepresented3,4.
Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. Trees can be constructed by using molecular methods such as the small subunit ribosomal gene.
The Tree of Life has been dramatically expanded through genome sequencing. However, there is still much diversity to be discovered. This is particularly true of microorganisms that are difficult to cultivate and are typically only represented in a single specimen5. Recent analysis of all genomes produced an initial draft of the Tree of Life. This includes a wide range of archaea, bacteria and other organisms that haven't yet been identified or whose diversity has not been thoroughly understood6.
This expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine if specific habitats require special protection. This information can be used in a variety of ways, from identifying new medicines to combating disease to enhancing crops. This information is also useful for conservation efforts. It can aid biologists in identifying areas that are most likely to be home to cryptic species, which could have vital metabolic functions, and could be susceptible to human-induced change. While conservation funds are important, the best method to preserve the world's biodiversity is to empower the people of developing nations with the necessary knowledge to act locally and promote conservation.
Phylogeny
A phylogeny, also called an evolutionary tree, illustrates the connections between groups of organisms. Using molecular data, morphological similarities and differences or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree that illustrates the evolutionary relationship between taxonomic categories. Phylogeny is crucial in understanding evolution, biodiversity and genetics.
A basic phylogenetic Tree (see Figure PageIndex 10 Determines the relationship between organisms that have similar characteristics and have evolved from an ancestor that shared traits. These shared traits could be analogous, or homologous. Homologous traits are similar in terms of their evolutionary journey. Analogous traits might appear like they are, but they do not have the same origins. Scientists arrange similar traits into a grouping referred to as a the clade. For example, all of the organisms that make up a clade share the trait of having amniotic egg and evolved from a common ancestor that had eggs. A phylogenetic tree is then built by connecting the clades to identify the organisms who are the closest to each other.
Scientists use molecular DNA or RNA data to build a phylogenetic chart that is more precise and precise. This information is more precise than morphological information and provides evidence of the evolutionary history of an individual or group. Researchers can use Molecular Data to calculate the age of evolution of organisms and identify the number of organisms that have a common ancestor.
The phylogenetic relationship can be affected by a variety of factors that include the phenotypic plasticity. This is a type behaviour that can change due to unique environmental conditions. This can cause a trait to appear more like a species another, obscuring the phylogenetic signal. However, this issue can be cured by the use of techniques such as cladistics which incorporate a combination of similar and homologous traits into the tree.
In addition, phylogenetics helps determine the duration and rate of speciation. This information can aid conservation biologists to decide which species to protect from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will lead to an ecosystem that is complete and balanced.
Evolutionary Theory
The fundamental concept in 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 variety of scientists, including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who envisioned an organism developing gradually according to its needs as well as the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that could be passed on to offspring.
In the 1930s and 1940s, ideas from a variety of fields--including natural selection, genetics, and particulate inheritance - came together to form the modern evolutionary theory synthesis which explains how evolution happens through the variation of genes within a population, and how those variants change in time as a result of natural selection. This model, which incorporates genetic drift, mutations, gene flow and sexual selection is mathematically described mathematically.
Recent discoveries in the field of evolutionary developmental biology have revealed the ways in which variation can be introduced to a species via mutations, genetic drift or reshuffling of genes in sexual reproduction, and even migration between populations. These processes, as well as other ones like directional selection and genetic erosion (changes in the frequency of the genotype over time), can lead to evolution that is defined as change in the genome of the species over time, and also the change in phenotype over time (the expression of that genotype in an individual).
Incorporating evolutionary thinking into all areas of biology education can improve student understanding of the concepts of phylogeny as well as evolution. A recent study conducted by Grunspan and colleagues, for example, showed that teaching about the evidence that supports evolution increased students' acceptance of evolution in a college biology course. For more information on how to teach evolution, see The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily: a Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have looked at evolution through the past--analyzing fossils and comparing species. They also observe living organisms. Evolution is not a past event; it is an ongoing process. Viruses evolve to stay away from new medications and bacteria mutate to resist antibiotics. 에볼루션코리아 alter their behavior in the wake of a changing world. The results are usually visible.
It wasn't until late 1980s that biologists understood that natural selection can be seen in action, as well. The key is the fact that different traits result in the ability to survive at different rates and reproduction, and they can be passed on from one generation to the next.
In the past, when one particular allele, the genetic sequence that controls coloration - was present in a group of interbreeding organisms, it could quickly become more prevalent than all other alleles. Over time, this would mean that the number of moths with black pigmentation may increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.
Observing evolutionary change in action is easier when a particular species has a fast generation turnover, as with bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from one strain. Samples from each population were taken regularly and more than 500.000 generations of E.coli have passed.
Lenski's research has demonstrated that mutations can alter the rate of change and the rate at which a population reproduces. It also demonstrates that evolution takes time, something that is hard for some to accept.
Microevolution is also evident in the fact that mosquito genes that confer resistance to pesticides are more prevalent in populations that have used insecticides. This is due to pesticides causing a selective pressure which favors those with resistant genotypes.
The rapidity of evolution has led to an increasing awareness of its significance especially in a planet that is largely shaped by human activity. This includes the effects of climate change, pollution and habitat loss that prevents many species from adapting. Understanding evolution will assist you in making better choices regarding the future of the planet and its inhabitants.