What Freud Can Teach Us About Evolution Site

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 comprehend the concept of evolution and how it influences every area of scientific inquiry.

This site offers a variety of tools for students, teachers, and general readers on evolution. It contains key 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 all life. It appears in many religions and cultures as symbolizing unity and love. It has many practical applications as well, including providing a framework for understanding the evolution of species and how they react to changes in environmental conditions.

The first attempts to depict the biological world were based on categorizing organisms based on their physical and metabolic characteristics. These methods, which are based on the collection of various parts of organisms or fragments of DNA, have significantly increased the diversity of a tree of Life2. These trees are mostly populated by eukaryotes and bacterial diversity is vastly underrepresented3,4.

Genetic techniques have greatly broadened our ability to depict the Tree of Life by circumventing the need for direct observation and experimentation. We can construct trees using molecular techniques, such as the small-subunit ribosomal gene.

Despite the dramatic growth of the Tree of Life through genome sequencing, a lot of biodiversity awaits discovery. This is particularly the case for microorganisms which are difficult to cultivate and are typically found in a single specimen5. A recent analysis of all genomes has produced a rough draft of a Tree of Life. This includes a large number of bacteria, archaea and other organisms that have not yet been isolated, or whose diversity has not been fully understood6.

The expanded Tree of Life can be used to determine the diversity of a specific region and determine if particular habitats need special protection. This information can be utilized in a range of ways, from identifying the most effective medicines to combating disease to enhancing the quality of crops. This information is also beneficial in conservation efforts. It can aid biologists in identifying areas that are most likely to have cryptic species, which could perform important metabolic functions and are susceptible to the effects of human activity. Although funds to protect biodiversity are essential, ultimately the best way to preserve the world's biodiversity is for more people living in developing countries to be equipped with the knowledge to act locally in order to promote conservation from within.

Phylogeny

A phylogeny (also known as an evolutionary tree) depicts the relationships between different organisms. Using molecular data as well as morphological similarities and distinctions or ontogeny (the process of the development of an organism), scientists can build a phylogenetic tree that illustrates the evolutionary relationship between taxonomic groups. Phylogeny is essential in understanding biodiversity, evolution and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms with similar characteristics and have evolved from an ancestor that shared traits. These shared traits could be analogous or homologous. Homologous characteristics are identical in terms of their evolutionary journey. Analogous traits might appear similar but they don't share the same origins. Scientists organize similar traits into a grouping called a clade. For instance, all of the species in a clade have the characteristic of having amniotic egg and evolved from a common ancestor who had these eggs. A phylogenetic tree can be constructed by connecting clades to determine the organisms which are the closest to each other.

Scientists utilize DNA or RNA molecular information to build a phylogenetic chart that is more precise and precise. This data is more precise than morphological information and provides evidence of the evolutionary background of an organism or group. Molecular data allows researchers to identify the number of organisms that share a common ancestor and to estimate their evolutionary age.

The phylogenetic relationship can be affected by a variety of factors such as the phenotypic plasticity. This is a kind of behaviour that can change due to specific environmental conditions. This can cause a trait to appear more similar to one species than other species, which can obscure the phylogenetic signal. This issue can be cured by using cladistics. This is a method that incorporates an amalgamation of homologous and analogous traits in the tree.

In addition, phylogenetics helps determine the duration and speed at which speciation takes place. This information can help conservation biologists make decisions about which species to protect from extinction. Ultimately, it is the preservation of phylogenetic diversity that will create a complete and balanced ecosystem.

Evolutionary Theory

The central theme in evolution is that organisms alter over time because of their interactions with their environment. Many scientists have proposed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that a living thing would develop according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern taxonomy system that is hierarchical and Jean-Baptiste Lamarck (1844-1829), who suggested that the usage or non-use of certain traits can result in changes that are passed on to the

In the 1930s & 1940s, concepts from various fields, including genetics, natural selection and particulate inheritance, merged to form a contemporary synthesis of evolution theory. This explains how evolution happens through the variation in genes within the population and how these variations change with time due to natural selection. This model, which incorporates genetic drift, mutations as well as gene flow and sexual selection is mathematically described mathematically.

Recent developments in the field of evolutionary developmental biology have revealed how variation can be introduced to a species by genetic drift, mutations, reshuffling genes during sexual reproduction, and even migration between populations. These processes, along with others such as directional selection and gene erosion (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).

evolutionkr.kr  can better understand phylogeny by incorporating evolutionary thinking throughout all aspects of biology. A recent study conducted by Grunspan and colleagues, for example revealed that teaching students about the evidence for evolution helped students accept the concept of evolution in a college-level biology course. To learn more about how to teach about evolution, please see The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have studied evolution by looking in the past--analyzing fossils and comparing species. They also study living organisms. Evolution is not a distant event, but an ongoing process. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior as a result of a changing world. The results are often evident.

It wasn't until late 1980s that biologists understood that natural selection can be observed in action as well. 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, when one particular allele, the genetic sequence that determines coloration--appeared in a group of interbreeding species, it could quickly become more common than the other alleles. In time, this could mean that the number of black moths in 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 see evolutionary change when the species, like bacteria, has a high generation turnover. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples of each are taken every day, and over 50,000 generations have now been observed.

Lenski's research has revealed that mutations can alter the rate at which change occurs and the rate at which a population reproduces. It also demonstrates that evolution takes time, something that is hard for some to accept.

Another example of microevolution is that mosquito genes that confer resistance to pesticides show up more often in populations where insecticides are used. This is because pesticides cause an enticement that favors individuals who have resistant genotypes.

The speed 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 hinder the species from adapting. Understanding the evolution process will help you make better decisions about the future of the planet and its inhabitants.