The Academy's Evolution Site

Biological evolution is one of the most central concepts in biology. The Academies have long been involved in helping people who are interested in science comprehend the concept of evolution and how it affects all areas of scientific exploration.

This site provides students, teachers and general readers with a wide range of educational resources on 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 a symbol of love and harmony in a variety of cultures. It also has important practical uses, like providing a framework for understanding the evolution 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 depend on the collection of various parts of organisms or short fragments of DNA, have greatly increased the diversity of a Tree of Life2. These trees are largely composed by eukaryotes and bacteria are largely underrepresented3,4.

Genetic techniques have greatly expanded our ability to depict the Tree of Life by circumventing the need for direct observation and experimentation. Trees can be constructed 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 diversity to be discovered. This is especially true of microorganisms, which are difficult to cultivate and are usually only found in a single sample5. Recent analysis of all genomes resulted in an unfinished draft of the Tree of Life. This includes a large number of archaea, bacteria and other organisms that have not yet been isolated, or 에볼루션 바카라사이트 whose diversity has not been thoroughly understood6.

The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, helping to determine if certain habitats require protection. This information can be used in a range of ways, from identifying new treatments to fight disease to improving crop yields. This information is also extremely useful to conservation efforts. It can aid biologists in identifying areas that are likely to be home to cryptic species, which could perform important metabolic functions and be vulnerable to the effects of human activity. While funds to safeguard biodiversity are vital however, the most effective method to preserve the world's biodiversity is for 에볼루션 카지노 more people in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny, also known as an evolutionary tree, shows the connections between different groups of organisms. Scientists can create an phylogenetic chart which shows the evolutionary relationship of taxonomic categories using molecular information and morphological differences or similarities. The concept of phylogeny is fundamental to understanding the evolution of biodiversity, evolution and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that evolved from common ancestral. These shared traits can be analogous or homologous. Homologous traits share their evolutionary origins, while analogous traits look like they do, but don't have the same ancestors. Scientists group similar traits into a grouping referred to as a clade. Every organism in a group have a common characteristic, like amniotic egg production. They all came from an ancestor who had these eggs. The clades are then linked to create a phylogenetic tree to determine which organisms have the closest connection to each other.

To create a more thorough and precise phylogenetic tree scientists rely on molecular information from DNA or RNA to establish the connections between organisms. This data is more precise than the morphological data and provides evidence of the evolutionary history of an individual or group. Researchers can utilize Molecular Data to determine the age of evolution of organisms and determine how many organisms have the same ancestor.

The phylogenetic relationships of organisms can be influenced by several factors including phenotypic plasticity, a kind of behavior 에볼루션바카라사이트 that changes in response to unique environmental conditions. This can cause a trait to appear more similar to a species than to the other and obscure the phylogenetic signals. However, this problem can be solved through the use of techniques such as cladistics which combine analogous and homologous features into the tree.

Additionally, phylogenetics aids predict the duration and rate at which speciation occurs. This information can aid conservation biologists in making choices about which species to safeguard from disappearance. Ultimately, it is the preservation of phylogenetic diversity which will create an ecologically balanced and complete ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms change over time due to their interactions with their environment. Many scientists have come up with theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that a living thing 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 suggested that the use or non-use of certain traits can result in changes that are passed on to the next generation.

In the 1930s and 1940s, ideas from various fields, including genetics, natural selection and particulate inheritance - came together to create the modern synthesis of evolutionary theory which explains how evolution occurs through the variation of genes within a population, and how those variants change over time as a result of natural selection. This model, 에볼루션바카라사이트 called genetic drift or mutation, gene flow, and sexual selection, is the foundation of modern evolutionary biology and 에볼루션 코리아 can be mathematically explained.

Recent developments in the field of evolutionary developmental biology have demonstrated that variation can be introduced into a species by genetic drift, mutation, and reshuffling genes during sexual reproduction, and also through the movement of populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of a genotype over time) can lead to evolution that is defined as change in the genome of the species over time and also by changes in phenotype over time (the expression of that genotype in an individual).

Incorporating evolutionary thinking into all aspects of biology education can improve students' understanding of phylogeny and evolutionary. A recent study conducted by Grunspan and colleagues, for instance revealed that teaching students about the evidence for evolution helped students accept the concept of evolution in a college-level biology course. For more information about how to teach evolution read The Evolutionary Potential in all Areas of Biology or Thinking Evolutionarily: a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Scientists have traditionally studied evolution by looking in the past, studying fossils, and comparing species. They also observe living organisms. However, evolution isn't something that occurred in the past, it's an ongoing process, that is taking place today. Bacteria mutate and resist antibiotics, viruses re-invent themselves and elude new medications, and animals adapt their behavior in response to the changing climate. The changes that result are often evident.

However, it wasn't until late 1980s that biologists realized that natural selection could be observed in action as well. The main reason is that different traits confer the ability to survive at different rates and reproduction, and can be passed on from generation to generation.

In the past when one particular allele - the genetic sequence that controls coloration - was present in a group of interbreeding organisms, it might quickly become more prevalent than the other alleles. Over time, that would mean the number of black moths in a population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to track evolution when an organism, 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 population are taken every day, and over fifty thousand generations have passed.

Lenski's work has shown that mutations can alter the rate of change and the efficiency of a population's reproduction. It also demonstrates that evolution takes time, a fact that some find difficult to accept.

Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more prevalent in areas that have used insecticides. That's because the use of pesticides creates a pressure that favors people with resistant genotypes.

The speed at which evolution can take place has led to a growing appreciation of its importance in a world shaped by human activities, including climate change, pollution, and the loss of habitats which prevent the species from adapting. Understanding evolution can help us make smarter decisions regarding the future of our planet and the lives of its inhabitants.