7 Things About Evolution Site You'll Kick Yourself For Not Knowing

The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been for a long time involved in helping people who are interested in science understand the theory of evolution and how it affects all areas of scientific exploration.

This site provides students, teachers and general readers with a range of learning resources on evolution. It includes 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 used in many religions and cultures as a symbol of unity and love. It also has many practical uses, like providing a framework for understanding the evolution of species and how they respond to changes in the environment.

The first attempts at depicting the biological world focused on the classification of species into distinct categories that had been distinguished by physical and metabolic characteristics1. These methods, which rely on the sampling of different parts of living organisms, or sequences of small fragments of their DNA significantly expanded the diversity that could be represented in the tree of life2. The trees are mostly composed by eukaryotes and bacteria are largely underrepresented3,4.

In avoiding the necessity of direct observation and experimentation genetic techniques have made it possible to represent the Tree of Life in a more precise way. We can create trees by using molecular methods like the small-subunit ribosomal gene.

The Tree of Life has been dramatically expanded through genome sequencing. However there is a lot of biodiversity to be discovered. This is especially true of microorganisms, which can be difficult to cultivate and are usually only present in a single sample5. A recent analysis of all genomes that are known has created a rough draft of the Tree of Life, including many archaea and bacteria that are not isolated and whose diversity is poorly understood6.

무료 에볼루션  expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine whether specific habitats require special protection. The information can be used in a range of ways, from identifying new remedies to fight diseases to improving crops. The information is also incredibly beneficial to conservation efforts. It can help biologists identify areas most likely to have cryptic species, which may have important metabolic functions, and could be susceptible to changes caused by humans. Although funds to protect biodiversity are essential however, the most effective method to preserve the world's biodiversity is for more people living in developing countries to be empowered with the knowledge to act locally to promote conservation from within.

Phylogeny

A phylogeny, also known as an evolutionary tree, illustrates the connections between various groups of organisms. Scientists can construct an phylogenetic chart which shows the evolutionary relationship of taxonomic groups based on molecular data and morphological similarities or differences. Phylogeny plays a crucial role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms that share similar traits that evolved from common ancestors. These shared traits can be either homologous or analogous. Homologous traits are identical in their evolutionary roots while analogous traits appear like they do, but don't have the identical origins. Scientists combine similar traits into a grouping called a clade. For example, all of the organisms that make up a clade share the trait of having amniotic eggs and evolved from a common ancestor who had these eggs. A phylogenetic tree is constructed by connecting clades to identify the species which are the closest to each other.

Scientists make use of molecular DNA or RNA data to construct a phylogenetic graph which is more precise and detailed. This information is more precise and gives evidence of the evolutionary history of an organism. Researchers can use Molecular Data to determine the evolutionary age of living organisms and discover how many organisms have the same ancestor.

The phylogenetic relationships of organisms can be influenced by several factors, including phenotypic flexibility, a type of behavior that changes in response to unique environmental conditions. This can cause a particular trait to appear more similar to one species than other species, which can obscure the phylogenetic signal. This problem can be addressed by using cladistics, which is a the combination of homologous and analogous features in the tree.

Furthermore, phylogenetics may help predict the time and pace of speciation. This information can assist conservation biologists in making choices about which species to safeguard from the threat of extinction. It is ultimately the preservation of phylogenetic diversity which will create an ecologically balanced and complete ecosystem.

Evolutionary Theory

The fundamental concept in evolution is that organisms change over time as a result of their interactions with their environment. Many theories of evolution have been proposed by a wide variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly in accordance with its needs as well as the Swedish botanist Carolus Linnaeus (1707-1778) who developed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or misuse of traits causes changes that could be passed on to offspring.

In the 1930s and 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance - came together to form the modern evolutionary theory synthesis, which defines how evolution is triggered by the variation of genes within a population, and how those variants change over time as a result of natural selection. This model, which is known as genetic drift, mutation, gene flow and sexual selection, is a key element of current evolutionary biology, and can be mathematically described.

Recent discoveries in evolutionary developmental biology have revealed the ways in which variation can be introduced to a species through genetic drift, mutations and reshuffling of genes during sexual reproduction and migration between populations. These processes, as well as other ones like the directional selection process and the erosion of genes (changes in the frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes within individuals).

Students can better understand the concept of phylogeny by using evolutionary thinking into all areas of biology. In a recent study conducted by Grunspan and co. It was found that teaching students about the evidence for evolution increased their acceptance of evolution during the course of a college biology. For more details about how to teach evolution, see The Evolutionary Power of Biology in All Areas of Biology or Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have studied evolution through looking back in the past--analyzing fossils and comparing species. They also study living organisms. However, evolution isn't something that occurred in the past; it's an ongoing process, happening in the present. Bacteria mutate and resist antibiotics, viruses evolve and are able to evade new medications and animals alter their behavior in response to the changing environment. The resulting changes are often evident.

It wasn't until the late 1980s that biologists began to realize that natural selection was in play. The key is that various traits confer different rates of survival and reproduction (differential fitness), and can be passed down from one generation to the next.

In the past, when one particular allele--the genetic sequence that defines color in a population of interbreeding organisms, it might rapidly become more common than the other alleles. As time passes, that could mean that the number of black moths within 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 fast generation turnover, as with bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain; samples of each are taken regularly and over 500.000 generations have been observed.

Lenski's research has demonstrated that mutations can alter the rate at which change occurs and the effectiveness at which a population reproduces. It also proves that evolution takes time--a fact that some people are unable to accept.

Microevolution can also be seen in the fact that mosquito genes that confer resistance to pesticides are more common in populations where insecticides are used. Pesticides create a selective pressure which favors those who have resistant genotypes.

The rapidity of evolution has led to a growing recognition of its importance, especially in a world shaped largely by human activity. This includes climate change, pollution, and habitat loss that prevents many species from adapting. Understanding the evolution process can help us make smarter decisions about the future of our planet, and the lives of its inhabitants.