The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies have been active for a long time in helping those interested in science comprehend the theory of evolution and how it influences all areas of scientific research.

This site offers a variety of tools for students, teachers, and general readers on evolution. It contains important video clips from NOVA and WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of all life. It is a symbol of love and unity across many cultures. It also has important practical applications, such as providing a framework to understand 에볼루션 the history of species and how they react to changing environmental conditions.

Early attempts to describe the world of biology were built on categorizing organisms based on their physical and 무료 에볼루션 metabolic characteristics. These methods, which rely on the collection of various parts of organisms or DNA fragments have greatly increased the diversity of a Tree of Life2. The trees are mostly composed by eukaryotes and bacteria are largely underrepresented3,4.

By avoiding the need for direct experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a more precise manner. Particularly, molecular methods allow us to build trees by using sequenced markers, such as the small subunit ribosomal gene.

Despite the massive expansion of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is especially relevant to microorganisms that are difficult to cultivate and are usually present in a single sample5. A recent analysis of all genomes known to date has produced a rough draft version of the Tree of Life, 에볼루션 바카라 including a large number of archaea and bacteria that have not been isolated and their diversity is not fully understood6.

This expanded Tree of Life is particularly useful for assessing the biodiversity of an area, assisting to determine if specific habitats require protection. This information can be utilized in a variety of ways, such as finding new drugs, battling diseases and improving crops. It is also useful in conservation efforts. It can help biologists identify areas that are most likely to have cryptic species, which may perform important metabolic functions, and could be susceptible to the effects of human activity. While funds to protect biodiversity are essential, the best way to conserve the biodiversity of the world is to equip more people in developing nations with the knowledge they need to act locally and support conservation.

Phylogeny

A phylogeny is also known as an evolutionary tree, shows the connections between various groups of organisms. Using molecular data similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can creics can help predict the length and speed of speciation. This information will assist conservation biologists in making choices about which species to safeguard from disappearance. In the end, 에볼루션카지노사이트 it is the preservation of phylogenetic diversity which will create an ecosystem that is complete and balanced.

Evolutionary Theory

The main idea behind evolution is that organisms alter over time because of their interactions with their environment. 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 believed that an organism would evolve slowly according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits can cause changes that can be passed onto offspring.

In the 1930s & 1940s, ideas from different fields, including genetics, natural selection, and particulate inheritance, were brought together to form a modern synthesis of evolution theory. This explains how evolution is triggered by the variation in genes within the population, and how these variants change with time due to natural selection. This model, which is known as genetic drift, mutation, gene flow and sexual selection, is the foundation of current evolutionary biology, and is mathematically described.

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 of genes in sexual reproduction, and also by migration between populations. These processes, along with others such as the directional selection process and the erosion of genes (changes to the frequency of genotypes over time), can lead towards evolution. Evolution is defined by changes in the genome over time, as well as changes in phenotype (the expression of genotypes in individuals).

Incorporating evolutionary thinking into all aspects of biology education can increase student understanding of the concepts of phylogeny and evolutionary. A recent study by Grunspan and colleagues, for instance demonstrated that teaching about the evidence supporting evolution increased students' understanding of evolution in a college-level biology course. For more details on how to teach evolution, see The Evolutionary Potency in all Areas of Biology or Thinking Evolutionarily as a Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution by studying fossils, comparing species, and observing 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 escape new drugs and animals change their behavior to the changing environment. The results are usually evident.

But it wasn't until the late 1980s that biologists realized that natural selection could be seen in action, as well. The main reason is that different traits can confer an individual rate of survival and reproduction, and they 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 group of interbreeding species, it could quickly become more prevalent than the other alleles. In time, this could mean that the number of moths with black pigmentation 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 evolutionary change when a species, such as bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from one strain. The samples of each population have been taken frequently and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has demonstrated that mutations can alter the rate of change and the effectiveness of a population's reproduction. It also demonstrates that evolution takes time, a fact that some find hard to accept.

Another example of microevolution is that mosquito genes that are resistant to pesticides show up more often in populations in which insecticides are utilized. This is due to pesticides causing an enticement that favors those with resistant genotypes.

The speed of evolution taking place has led to a growing appreciation of its importance in a world shaped by human activity--including climate change, 무료 에볼루션 pollution and the loss of habitats that prevent many species from adapting. Understanding the evolution process can help us make smarter decisions regarding the future of our planet as well as the lives of its inhabitants.