The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies have long been involved in helping people who are interested in science understand the concept of evolution and how it affects every area of scientific inquiry.

This site provides students, teachers and general readers with a variety of learning resources on evolution. It contains key video clips from NOVA and the WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol of the interconnectedness of all life. It is used in many cultures and spiritual beliefs as an emblem of unity and love. It also has practical uses, like providing a framework to understand the evolution of species and how they react to changes in the environment.

Early attempts to describe the biological world were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which relied on the sampling of various parts of living organisms, or sequences of short DNA fragments, significantly expanded the diversity that could be represented in the tree of life2. The trees are mostly composed by eukaryotes and the diversity of bacterial species is greatly underrepresented3,4.

By avoiding the necessity for direct experimentation and 에볼루션카지노사이트 observation genetic techniques have enabled us to depict the Tree of Life in a more precise manner. In particular, molecular methods allow us to construct trees using sequenced markers, such as the small subunit of ribosomal RNA gene.

The Tree of Life has been significantly expanded by genome sequencing. However, there is still much diversity to be discovered. This is particularly true for microorganisms, which are difficult to cultivate and are often only represented in a single sample5. A recent analysis of all genomes known to date has produced a rough draft of the Tree of Life, including a large number of archaea and bacteria that have not been isolated, and their diversity is not fully understood6.

The expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine whether specific habitats require special protection. This information can be used in a variety of ways, from identifying the most effective treatments to fight disease to enhancing crops. This information is also extremely valuable in conservation efforts. It can aid biologists in identifying areas most likely to have cryptic species, which may have important metabolic functions, and could be susceptible to changes caused by humans. While funding to protect biodiversity are important, the most effective method to protect the world's biodiversity is to empower more people in developing countries with the knowledge they need to take action locally and encourage conservation.

Phylogeny

A phylogeny (also known as an evolutionary tree) depicts the relationships between species. Using molecular data similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can create a phylogenetic tree which illustrates the evolutionary relationship between taxonomic categories of phylogenetic diversity that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

The central theme of evolution is that organisms acquire various characteristics over time due to their interactions with their environments. Many theories of evolution 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 in accordance with its needs as well as the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that could be passed onto offspring.

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

Recent developments in evolutionary developmental biology have demonstrated how variation can be introduced to a species by genetic drift, mutations or reshuffling of genes in sexual reproduction and 에볼루션 무료체험 migration between populations. These processes, in conjunction 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 and changes in the phenotype (the expression of genotypes in an individual).

Students can better understand phylogeny by incorporating evolutionary thinking into all aspects of biology. A recent study by Grunspan and colleagues, for example revealed that teaching students about the evidence supporting evolution increased students' understanding of evolution in a college biology course. To learn more about 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 through looking back, studying fossils, comparing species and observing living organisms. Evolution is not a distant moment; it is an ongoing process that continues to be observed today. Bacteria mutate and resist antibiotics, viruses reinvent themselves and are able to evade new medications and animals change their behavior to the changing environment. The changes that occur are often evident.

It wasn't until late 1980s that biologists began realize that natural selection was also in action. The key is the fact that different traits can confer a different rate of survival as well as reproduction, and may be passed on from one generation to the next.

In the past, 에볼루션 바카라 무료체험카지노사이트 (Buckley-Miles.Blogbright.Net) if one particular allele--the genetic sequence that determines coloration--appeared in a group of interbreeding organisms, it might quickly become more prevalent than other alleles. As time passes, that could mean that the number of black moths within a particular population could rise. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to observe evolutionary change when a species, such as bacteria, has a high generation turnover. 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 every day and over 500.000 generations have been observed.

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

Microevolution can be observed in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides have been used. This is due to pesticides causing an exclusive pressure that favors those who have resistant genotypes.

The rapid pace of evolution taking place has led to a growing appreciation of its importance in a world shaped by human activity--including climate changes, pollution and the loss of habitats which prevent the species from adapting. Understanding the evolution process will help us make better decisions regarding the future of our planet, as well as the life of its inhabitants.