20 Resources That Will Make You Better At Evolution Site

The Academy's Evolution Site

Biology is one of the most central 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 permeates every area of scientific inquiry.

This site provides teachers, students and general readers with a variety of learning resources about evolution. It also includes important video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol of the interconnectedness of life. It is an emblem of love and harmony in a variety of cultures. It can be used in many practical ways in addition to providing a framework for understanding the history of species and how they react to changes in environmental conditions.

The first attempts to depict the biological world were built on categorizing organisms based on their physical and metabolic characteristics. These methods, which rely on the sampling of various parts of living organisms or sequences of small fragments of their DNA significantly increased the variety that could be included in the tree of life2. However the trees are mostly comprised of eukaryotes, and bacterial diversity is not represented in a large way3,4.

By avoiding the necessity for direct experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a much more accurate way. We can construct trees using molecular methods such as the small subunit ribosomal gene.

Despite the dramatic expansion of the Tree of Life through genome sequencing, a lot of biodiversity remains to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are typically found in one sample5. A recent analysis of all genomes produced an unfinished draft of the Tree of Life. This includes a wide range of bacteria, archaea and other organisms that have not yet been isolated or their diversity is not thoroughly understood6.

This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, assisting to determine if certain habitats require protection. This information can be utilized in a range of ways, from identifying new remedies to fight diseases to improving crops. This information is also extremely useful in conservation efforts. It helps biologists determine the areas most likely to contain cryptic species with potentially significant metabolic functions that could be at risk of anthropogenic changes. While funding to protect biodiversity are important, the best way to conserve the world's biodiversity is to equip more people in developing countries with the knowledge they need to act locally and support conservation.

Phylogeny

A phylogeny (also called an evolutionary tree) illustrates the relationship between organisms. Using molecular data similarities and differences in morphology or ontogeny (the course of development of an organism) scientists can create a phylogenetic tree that illustrates the evolution of taxonomic categories. Phylogeny is crucial in understanding evolution, biodiversity and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and evolved from a common ancestor. These shared traits are either homologous or analogous. Homologous characteristics are identical in terms of their evolutionary journey. Analogous traits may look like they are but they don't have the same ancestry. Scientists group similar traits together into a grouping known as a clade. Every organism in a group have a common trait, such as amniotic egg production. They all came from an ancestor who had these eggs. A phylogenetic tree is then built by connecting the clades to identify the species which are the closest to each other.

Scientists use molecular DNA or RNA data to build a phylogenetic chart that is more accurate and precise. This information is more precise and gives evidence of the evolution history of an organism. Molecular data allows researchers to determine the number of species who share an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic plasticity a kind of behavior that changes in response to unique environmental conditions. This can cause a particular trait to appear more similar to one species than another, clouding the phylogenetic signal. However, this problem can be solved through the use of methods such as cladistics which include a mix of homologous and analogous features into the tree.

Additionally, phylogenetics can help determine the duration and rate of speciation. This information will assist conservation biologists in deciding which species to save from the threat of extinction. It is ultimately the preservation of phylogenetic diversity that will lead to 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 an organism could develop according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of traits can cause changes that are passed on to the

In the 1930s and 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance -- came together to form the current synthesis of evolutionary theory that explains how evolution happens through the variations of genes within a population, and how those variants change over time as a result of natural selection.  에볼루션 코리아 , which incorporates mutations, genetic drift as well as gene flow and sexual selection, can be mathematically described.

Recent advances in evolutionary developmental biology have shown how variations can be introduced to a species through genetic drift, mutations and reshuffling of genes during sexual reproduction and migration between populations. These processes, in conjunction with others such as directionally-selected selection and erosion of genes (changes in frequency of genotypes over time) can result in evolution. Evolution is defined as changes in the genome over time as well as changes in the phenotype (the expression of genotypes in an individual).

Incorporating evolutionary thinking into all aspects of biology education can improve student understanding of the concepts of phylogeny and evolution. A recent study 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 biology course. To find out more about how to teach about evolution, see The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing the Concept of Evolution into Life Sciences Education.

Evolution in Action

Traditionally, scientists have studied evolution through looking back, studying fossils, comparing species and studying living organisms. Evolution isn't a flims moment; it is an ongoing process that continues to be observed today. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior because of the changing environment. The results are usually easy to see.

But it wasn't until the late-1980s that biologists realized that natural selection can be observed in action as well. The key is the fact that different traits confer a different rate of survival and reproduction, and can be passed on from generation to generation.

In the past, if one allele - the genetic sequence that determines colour - was present in a population of organisms that interbred, it could be more common than any other allele. In time, this could mean the number of black moths within a population could 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 much easier when a species has a fast generation turnover, 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 fifty thousand generations have been observed.

Lenski's research has shown that a mutation can profoundly alter the rate at which a population reproduces--and so, the rate at which it changes. It also shows that evolution is slow-moving, a fact that some people find difficult to accept.

Another example of microevolution is that mosquito genes for resistance to pesticides are more prevalent in populations where insecticides are used. Pesticides create an enticement that favors those who have resistant genotypes.

The rapid pace of evolution taking place has led to an increasing appreciation of its importance in a world that is shaped by human activity, including climate changes, pollution and the loss of habitats that prevent many species from adjusting. Understanding the evolution process can help us make smarter decisions about the future of our planet as well as the life of its inhabitants.