10 Things Everybody Hates About Evolution Site

The Academy's Evolution Site

Biological evolution is one of the most important concepts in biology. The Academies are committed to helping those who are interested in science understand evolution theory and how it is incorporated in all areas of scientific research.

This site provides a range of sources for students, teachers and general readers of evolution. It includes key video clips from NOVA and the WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is an emblem of love and unity across many cultures. It can be used in many practical ways as well, such as providing a framework to understand the history of species, and how they react to changing environmental conditions.

The first attempts at depicting the biological world focused on the classification of organisms into distinct categories that had been identified by their physical and metabolic characteristics1. These methods, which depend on the collection of various parts of organisms or short DNA fragments have significantly increased the diversity of a tree of Life2. The trees are mostly composed by eukaryotes and bacteria are largely underrepresented3,4.

Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. In particular, molecular methods enable us to create trees by using sequenced markers like the small subunit ribosomal RNA gene.

The Tree of Life has been significantly expanded by genome sequencing. However there is still a lot of biodiversity to be discovered. This is particularly true for microorganisms that are difficult to cultivate, and which are usually only found in one sample5. A recent analysis of all genomes produced an initial draft of the Tree of Life. This includes a variety of archaea, bacteria, and other organisms that have not yet been isolated or their diversity is not thoroughly understood6.

The expanded Tree of Life can be used to determine the diversity of a specific area and determine if certain habitats require special protection. This information can be used in a variety of ways, including finding new drugs, fighting diseases and enhancing crops. It is also useful to conservation efforts. It can aid biologists in identifying the areas that are most likely to contain cryptic species with important metabolic functions that may be vulnerable to anthropogenic change. Although funds to safeguard biodiversity are vital but the most effective way to ensure the preservation of biodiversity around the world is for more people living in developing countries to be empowered with the necessary knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, illustrates the relationships between different groups of organisms. Using molecular data similarities and differences in morphology, or ontogeny (the process of the development of an organism) scientists can construct a phylogenetic tree which illustrates the evolution of taxonomic groups. The concept of phylogeny is fundamental to understanding evolution, biodiversity and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that evolved from common ancestors. These shared traits can be either homologous or analogous. Homologous characteristics are identical in their evolutionary path. Analogous traits may look like they are, but they do not share the same origins. Scientists organize similar traits into a grouping called a the clade. For instance, all of the organisms that make up a clade share the trait of having amniotic eggs. They evolved from a common ancestor which had these eggs. A phylogenetic tree can be built by connecting the clades to determine the organisms who are the closest to each other.

For a more detailed and accurate phylogenetic tree, scientists make use of molecular data from DNA or 에볼루션 코리아 무료체험 [prev] RNA to identify the relationships among organisms. This information is more precise and 에볼루션 바카라 (Airemploy.Co.uk) gives evidence of the evolutionary history of an organism. The use of molecular data lets researchers identify the number of organisms who share an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships of organisms can be influenced by several factors, including phenotypic plasticity a kind of behavior that changes in response to specific environmental conditions. This can cause a particular trait to appear more like a species another, obscuring the phylogenetic signal. This issue can be cured by using cladistics, which incorporates the combination of homologous and analogous features in the tree.

In addition, phylogenetics helps determine the duration and rate at which speciation takes place. This information can assist conservation biologists in making choices about which species to protect from the threat of extinction. In the end, it's the conservation of phylogenetic variety that will result in an ecosystem that is balanced and complete.

Evolutionary Theory

The fundamental concept in evolution is that organisms alter over time because of their interactions with their environment. A variety of theories about evolution have been proposed by a variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly in accordance with its requirements and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that could be passed on to offspring.

In the 1930s and 1940s, theories from various fields, including genetics, natural selection and particulate inheritance, merged to create a modern synthesis of evolution theory. This describes how evolution is triggered by the variation in genes within the population, and how these variations alter over time due to natural selection. This model, which incorporates genetic drift, mutations as well as gene flow and sexual selection can be mathematically described mathematically.

Recent developments in the field of evolutionary developmental biology have revealed that genetic variation can be introduced into a species by mutation, genetic drift, and reshuffling genes during sexual reproduction, and also by migration between populations. These processes, as well as others such as directional selection or genetic erosion (changes in the frequency of an individual's genotype over time), can lead to evolution which is defined by change in the genome of the species over time and the change in phenotype as time passes (the expression of the genotype in the individual).

Incorporating evolutionary thinking into all areas of biology education can improve student understanding of the concepts of phylogeny as well as evolution. A recent study by Grunspan and colleagues, for instance, showed that teaching about the evidence for evolution increased students' acceptance of evolution in a college-level biology course. For more details on how to teach evolution look up The Evolutionary Potential in All Areas of Biology or Thinking Evolutionarily: a Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have looked at evolution through the past, studying fossils, and comparing species. They also observe living organisms. But evolution isn't just something that occurred in the past, it's an ongoing process, taking place today. The virus reinvents itself to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior as a result of a changing world. The results are usually evident.

It wasn't until the late 1980s that biologists began realize that natural selection was also in action. The key to this is that different traits confer the ability to survive at different rates and reproduction, and can be passed on from one generation to the next.

In the past, if a certain allele - the genetic sequence that determines colour appeared in a population of organisms that interbred, it might become more prevalent than any other allele. Over time, that would mean that the number of black moths in the 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 observe evolution when an organism, like bacteria, has a rapid generation turnover. 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 regularly, and over 500.000 generations 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 proves that evolution is slow-moving, a fact that many are unable 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. Pesticides create a selective pressure which favors individuals who have resistant genotypes.

The rapidity of evolution has led to an increasing awareness of its significance, especially in a world that is largely shaped by human activity. This includes climate change, pollution, and habitat loss, which prevents many species from adapting. Understanding evolution will help us make better decisions regarding the future of our planet as well as the life of its inhabitants.