The Academy's Evolution Site

Biological evolution is a central concept in biology. The Academies have long been involved in helping those interested in science comprehend the concept of evolution and how it influences all areas of scientific exploration.

This site provides a range of sources for students, teachers and general readers of evolution. It has 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 seen in a variety of religions and cultures as a symbol of unity and love. It also has many practical applications, such as providing a framework for understanding the history of species and how they respond to changes in environmental conditions.

The first attempts at depicting the world of biology focused on separating organisms into distinct categories which had been distinguished by their physical and metabolic characteristics1. These methods, which depend on the collection of various parts of organisms or fragments of DNA, have greatly increased the diversity of a tree of Life2. However the trees are mostly made up of eukaryotes. Bacterial diversity remains vastly underrepresented3,4.

Genetic techniques have significantly expanded our ability to represent the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular techniques allow us to build trees by using sequenced markers, such as the small subunit of ribosomal RNA gene.

Despite the rapid expansion of the Tree of Life through genome sequencing, a lot of biodiversity is waiting to be discovered. This is particularly relevant to microorganisms that are difficult to cultivate and which are usually only present in a single sample5. A recent analysis of all genomes resulted in an unfinished draft of a Tree of Life. This includes a large number of archaea, bacteria and other organisms that haven't yet been identified or their diversity is not well understood6.

This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, 에볼루션 코리아 which can help to determine whether specific habitats require special protection. This information can be utilized in a range of ways, from identifying the most effective remedies to fight diseases to enhancing the quality of crops. This information is also extremely useful in conservation efforts. It can help biologists identify the areas most likely to contain cryptic species that could have important metabolic functions that could be vulnerable to anthropogenic change. Although funds to safeguard biodiversity are vital but the most effective way to preserve the world's biodiversity is for more people in developing countries to be empowered with the knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny, also known as an evolutionary tree, illustrates the connections between groups of organisms. Scientists can build a phylogenetic diagnalogous and homologous features into the tree.

Additionally, phylogenetics aids determine the duration and speed at which speciation takes place. This information can aid conservation biologists in making choices about which species to safeguard from disappearance. In the end, it's the preservation of phylogenetic diversity that will result in an ecosystem that is balanced and complete.

Evolutionary Theory

The central theme of evolution is that organisms develop different features over time due to their interactions with their environments. Several theories of evolutionary change have been developed by a variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who envisioned an organism developing slowly according to its requirements as well as the Swedish botanist Carolus Linnaeus (1707-1778) who developed modern hierarchical taxonomy, and 에볼루션 코리아 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, ideas from different areas, including natural selection, genetics & particulate inheritance, were brought together to create a modern theorizing of evolution. This defines how evolution happens through the variation of genes in a population and how these variations alter over time due to natural selection. This model, which encompasses mutations, genetic drift as well as gene flow and sexual selection can be mathematically described mathematically.

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

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 understanding of evolution during a college-level course in biology. For more information on how to teach about evolution, look up The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Traditionally, scientists have studied evolution by looking back--analyzing fossils, comparing species and studying living organisms. Evolution isn't a flims event, but an ongoing process that continues to be observed today. Bacteria transform and resist antibiotics, viruses reinvent themselves and are able to evade new medications and animals alter their behavior in response to the changing climate. The changes that result are often evident.

It wasn't until late 1980s when biologists began to realize that natural selection was also in action. The reason is that different traits have different rates of survival and reproduction (differential fitness), and can be transferred from one generation to the next.

In the past, if an allele - the genetic sequence that determines color - appeared in a population of organisms that interbred, it might become more prevalent than any other allele. As time passes, this could mean that the number of moths with 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.

Observing evolutionary change in action is easier when a particular species has a rapid turnover of its generation, as with bacteria. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain. samples from each population are taken every day and over 50,000 generations have now passed.

Lenski's research has demonstrated that mutations can alter the rate of change and the effectiveness of a population's reproduction. It also shows evolution takes time, which is difficult for some to accept.

Another example of microevolution is the way mosquito genes that confer resistance to pesticides appear more frequently in areas where insecticides are used. This is because the use of pesticides creates a selective pressure that favors people with resistant genotypes.

The rapidity of evolution has led to a greater appreciation of its importance particularly in a world shaped largely by human activity. This includes the effects of climate change, pollution and habitat loss that hinders many species from adapting. Understanding the evolution process will help us make better choices about the future of our planet as well as the lives of its inhabitants.