The Academy's Evolution Site
Biology is a key concept in biology. The Academies have been active for a long time in helping people who are interested in science understand the theory of evolution and how it affects all areas of scientific research.
This site provides students, teachers and general readers with a variety of learning resources on 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 of the interconnectedness of life. It is a symbol of love and harmony in a variety of cultures. It also has many practical applications, like providing a framework for understanding the history of species and how they respond to changing environmental conditions.
The first attempts to depict the world of biology were based on categorizing organisms based on their physical and metabolic characteristics. These methods, which relied on sampling of different parts of living organisms, or short fragments of their DNA greatly increased the variety of organisms that could be included in the tree of life2. The trees are mostly composed by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4.
By avoiding the necessity for direct observation and experimentation, genetic techniques have allowed us to represent the Tree of Life in a more precise way. We can create trees using molecular methods, such as the small-subunit ribosomal gene.
Despite the rapid expansion of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are often only found in a single sample5. A recent study of all known genomes has produced a rough draft of the Tree of Life, including a large number of archaea and bacteria that are not isolated and which are not well understood.
This expanded Tree of Life can be used to determine the diversity of a specific region and determine if particular habitats need special protection. This information can be utilized in a variety of ways, including identifying new drugs, combating diseases and enhancing crops. It is also beneficial for conservation efforts. It helps biologists determine the areas that are most likely to contain cryptic species that could have important metabolic functions that may be at risk of anthropogenic changes. Although funding to protect biodiversity are essential however, the most effective method to protect the world's biodiversity is for more people living in developing countries to be empowered with the necessary knowledge to act locally in order to promote conservation from within.
Phylogeny
A phylogeny (also known as an evolutionary tree) shows the relationships between species. By using molecular information similarities and differences in morphology or ontogeny (the process of the development of an organism), scientists can build a phylogenetic tree which illustrates the evolutionary relationships between taxonomic categories. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution.
A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms that have similar traits and evolved from a common ancestor. These shared traits can be analogous, or homologous. Homologous traits are the same in their evolutionary journey. Analogous traits could appear like they are however they do not have the same ancestry. Scientists group similar traits into a grouping referred to as a clade. Every organism in a group share a characteristic, like amniotic egg production. They all derived from an ancestor who had these eggs. A phylogenetic tree can be built by connecting the clades to identify the organisms who are the closest to each other.
Scientists utilize molecular DNA or RNA data to build a phylogenetic chart that is more precise and precise. This information is more precise than morphological data and provides evidence of the evolution background of an organism or group. Researchers can utilize Molecular Data to determine the age of evolution of organisms and identify the number of organisms that have a common ancestor.
The phylogenetic relationships of a species can be affected by a number of factors, including the phenotypic plasticity. This is a type of behavior that alters due to particular environmental conditions. This can cause a particular trait to appear more similar to one species than another, obscuring the phylogenetic signal. This problem can be mitigated by using cladistics. This is a method that incorporates a combination of homologous and analogous traits in the tree.
Additionally, phylogenetics can help determine the duration and rate at which speciation takes place. This information can help conservation biologists make decisions about which species they should protect from the threat of extinction. In the end, it is the conservation of phylogenetic diversity which will create an ecosystem that is complete and balanced.
Evolutionary Theory
The main idea behind evolution is that organisms change over time due to their interactions with their environment. Many scientists have developed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism would develop according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the use or absence of certain traits can result in changes that are passed on to the
In the 1930s & 1940s, concepts from various fields, including genetics, natural selection, and particulate inheritance, merged to form a modern evolutionary theory. This explains how evolution happens through the variation of genes in the population, and how these variations change with time due to natural selection. This model, which includes genetic drift, mutations as well as gene flow and sexual selection is mathematically described mathematically.
Recent developments in the field of evolutionary developmental biology have shown that variation can be introduced into a species by genetic drift, mutation, and reshuffling of genes during sexual reproduction, as well as through the movement of populations. These processes, in conjunction with other ones like the directional selection process and the erosion of genes (changes in the frequency of genotypes over time) can result in evolution. 에볼루션 슬롯게임 is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes in individuals).
Incorporating evolutionary thinking into all areas of biology education can improve students' understanding of phylogeny as well as evolution. A recent study conducted by Grunspan and colleagues, for instance revealed that teaching students about the evidence supporting evolution helped students accept the concept of evolution in a college-level biology class. For more information on how to teach about evolution, 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
Scientists have looked at evolution through the past, studying fossils, and comparing species. They also study living organisms. Evolution is not a distant event, but a process that continues today. Viruses reinvent themselves to avoid new medications and bacteria mutate to resist antibiotics. Animals alter their behavior as a result of a changing world. The resulting changes are often easy to see.
However, it wasn't until late 1980s that biologists understood that natural selection can be seen in action, as well. The key to this is that different traits can confer the ability to survive at different rates as well as reproduction, and may be passed on from generation to generation.
In the past when one particular allele - the genetic sequence that defines color in a population of interbreeding organisms, it might quickly become more prevalent than the other alleles. Over time, this would mean that the number of moths sporting black pigmentation in a group could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.
It is easier to observe evolutionary change 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 of each are taken on a regular basis and over fifty thousand generations have passed.
Lenski's research has revealed that mutations can drastically alter the rate at which a population reproduces--and so, the rate at which it changes. It also demonstrates that evolution takes time--a fact that many find hard to accept.
Microevolution can also be seen in the fact that mosquito genes for resistance to pesticides are more prevalent in populations that have used insecticides. This is due to the fact that the use of pesticides causes a selective pressure that favors people with resistant genotypes.
The rapid pace at which evolution takes place has led to an increasing appreciation of its importance in a world shaped by human activity--including climate change, pollution and the loss of habitats that prevent many species from adapting. Understanding the evolution process will help you make better decisions about the future of the planet and its inhabitants.