The 12 Best Evolution Site Accounts To Follow On Twitter

The Academy's Evolution Site

The concept of biological evolution is among the most fundamental concepts in biology. The Academies are involved in helping those who are interested in science to understand evolution theory and how it can be applied in all areas of scientific research.

This site provides teachers, students and general readers with a wide range of learning resources about evolution. It contains key video clips from NOVA and WGBH produced 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 spiritual traditions and cultures as a symbol of unity and love. It also has practical uses, like providing a framework for understanding the history of species and how they react to changes in environmental conditions.

Early attempts to represent the biological world were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which relied on the 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, these trees are largely made up of eukaryotes. Bacterial diversity remains vastly underrepresented3,4.

By avoiding the necessity for direct experimentation and observation, genetic techniques have made it possible to represent the Tree of Life in a much more accurate way. Trees can be constructed using molecular methods such as the small subunit ribosomal gene.

The Tree of Life has been significantly expanded by genome sequencing. However there is still a lot of diversity to be discovered. This is particularly true of microorganisms that are difficult to cultivate and are usually only found in a single specimen5. A recent analysis of all genomes that are known has produced a rough draft version of the Tree of Life, including numerous bacteria and archaea that are not isolated and their diversity is not fully understood6.

This expanded Tree of Life can be used to determine the diversity of a specific area and determine if particular habitats require special protection. The information is useful in a variety of ways, such as finding new drugs, battling diseases and improving the quality of crops. The information is also incredibly useful to conservation efforts. It can help biologists identify areas most likely to be home to cryptic species, which could perform important metabolic functions, and could be susceptible to human-induced change. While funds to protect biodiversity are crucial but the most effective way to ensure the preservation of biodiversity around the world 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 relationships between groups of organisms. Utilizing molecular data, morphological similarities and differences or ontogeny (the process of the development of an organism), scientists can build an phylogenetic tree that demonstrates the evolutionary relationships between taxonomic groups. Phylogeny is essential in understanding biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that evolved from common ancestors. These shared traits may be homologous, or analogous. Homologous traits are similar in their evolutionary paths. Analogous traits could appear similar however they do not have the same origins. Scientists organize similar traits into a grouping known 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 constructed by connecting clades to identify the organisms who are the closest to one another.

To create a more thorough and precise phylogenetic tree scientists make use of molecular data from DNA or RNA to establish the relationships among organisms. This information is more precise than morphological data and gives evidence of the evolutionary history of an individual or group. Molecular data allows researchers to determine the number of organisms that have an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships between species can be influenced by several factors, including phenotypic plasticity a kind of behavior that alters in response to unique environmental conditions. This can cause a characteristic to appear more like a species another, obscuring the phylogenetic signal. However, this problem can be cured by the use of methods such as cladistics which incorporate a combination of similar and homologous traits into the tree.

Additionally, phylogenetics can help predict the duration and rate of speciation. This information can aid conservation biologists in making decisions about which species to safeguard from disappearance. In  무료 에볼루션 , it's the preservation of phylogenetic diversity that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

The central theme in evolution is that organisms alter over time because of their interactions with their environment. A variety of theories about evolution have been developed by a wide range of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who envisioned an organism developing gradually according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that can be passed on to the offspring.

In the 1930s and 1940s, concepts from a variety of fields--including natural selection, genetics, and particulate inheritance--came together to create the modern evolutionary theory synthesis that explains how evolution is triggered by the variation of genes within a population, and how those variations change in time as a result of natural selection. This model, known as genetic drift, mutation, gene flow, and sexual selection, is the foundation of current evolutionary biology, and can be mathematically described.

Recent discoveries in the field of evolutionary developmental biology have demonstrated how variation can be introduced to a species via genetic drift, mutations, reshuffling genes during sexual reproduction and the movement between populations. These processes, along with others such as the directional selection process and the erosion of genes (changes in 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 within individuals).

Incorporating evolutionary thinking into all areas of biology education could increase student understanding of the concepts of phylogeny as well as evolution. In a recent study by Grunspan and co., it was shown that teaching students about the evidence for evolution increased their acceptance of evolution during an undergraduate biology course. To learn more about how to teach about evolution, see The Evolutionary Potential of 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 observe living organisms. But evolution isn't a thing that happened in the past, it's an ongoing process that is taking place right now. Bacteria mutate and resist antibiotics, viruses reinvent themselves and are able to evade new medications and animals alter their behavior in response to a changing planet. The changes that occur are often evident.

It wasn't until the late 1980s when biologists began to realize that natural selection was also in action. The key to this is that different traits result in the ability to survive at different rates as well as reproduction, and may be passed on from one generation to another.

In the past, if one allele - the genetic sequence that determines colour - was found in a group of organisms that interbred, it could become more common than other allele. As time passes, this could mean that the number of moths sporting 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 species has a rapid generation turnover like bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain. samples of each population are taken every day and more than fifty thousand generations have passed.

Lenski's research has revealed that a mutation can dramatically alter the efficiency with which a population reproduces--and so, the rate at which it evolves. It also proves that evolution takes time--a fact that many find difficult to accept.

Another example of microevolution is the way mosquito genes that are resistant to pesticides show up more often in populations in which insecticides are utilized. This is due to the fact that the use of pesticides creates a pressure that favors those with resistant genotypes.

The rapidity of evolution has led to a greater recognition 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 can help us make better choices about the future of our planet, as well as the lives of its inhabitants.