The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been for a long time involved in helping people who are interested in science comprehend the concept of evolution and how it affects all areas of scientific research.

This site offers a variety of resources for teachers, students as well as general readers about evolution. It includes key video clips from NOVA and WGBH's science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of life. It is an emblem of love and harmony in a variety of cultures. It has many practical applications as well, such as providing a framework to understand the history of species, and how they respond to changes in environmental conditions.

The first attempts at depicting the world of biology focused on the classification of organisms into distinct categories which had been identified by their physical and metabolic characteristics1. These methods, which depend on the collection of various parts of organisms or short fragments of DNA have significantly increased the diversity of a tree of Life2. However these trees are mainly comprised of eukaryotes, and bacterial diversity is not represented in a large way3,4.

Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the need for direct observation and experimentation. Particularly, molecular techniques enable us to create trees by using sequenced markers, such as the small subunit ribosomal RNA gene.

Despite the dramatic expansion of the Tree of Life through genome sequencing, much biodiversity still is waiting to be discovered. This is especially relevant to microorganisms that are difficult to cultivate and are usually found in one sample5. A recent analysis of all known genomes has created a rough draft of the Tree of Life, including numerous bacteria and archaea that have not been isolated and their diversity is not fully understood6.

This expanded Tree of Life is particularly useful in assessing the diversity of an area, assisting to determine if certain habitats require protection. This information can be utilized in a range of ways, from identifying new treatments to fight disease to enhancing the quality of crops. This information is also extremely useful for conservation efforts. It can help biologists identify those areas that are most likely contain cryptic species that could have important metabolic functions that may be vulnerable to anthropogenic change. While funds to protect biodiversity are essential but the most effective way to ensure the preservation of biodiversity around the world is for more people in developing countries to be empowered with the knowledge to act locally to promote conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, shows the relationships between groups of organisms. Utilizing molecular data similarities and differences in morphology, or ontogeny (the process of the development of an organism) scientists can construct an phylogenetic tree that demonstrates the evolutionary relationships between taxonomic groups. Phylogeny plays a crucial role in understanding genetics, 에볼루션 무료체험게이밍 (Https://K12.instructure.Com) biodiversity and 에볼루션 무료체험 (Appc.Cctvdgrw.Com) evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms that have similar traits and evolved from an ancestor with common traits. These shared traits could be homologous, or analogous. Homologous characteristics are identical in terms of their evolutionary paths. 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 evolved from an ancestor who had these eggs. The clades then join to form a phylogenetic branch to determine which organisms have the closest relationship to.

For a more precise and precise phylogenetic tree scientists make use of molecular data from DNA or RNA to identify the relationships among organisms. This information is more precise and gives evidence of the evolution of an organism. Molecular data allows researchers to determine the number of organisms that share a common ancestor and to estimate their evolutionary age.

The phylogenetic relationships of organisms can be affected by a variety of factors including phenotypic plasticity, a kind of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more similar to one species than another, clouding the phylogenetic signal. However, this issue can be solved through the use of methods like cladistics, which combine similar and homologous traits into the tree.

Additionally, phylogenetics can help predict the duration and rate of speciation. This information can aid conservation biologists to make decisions about which species they should protect from the threat of extinction. In the end, it is the conservation of phylogenetic variety that will lead to an ecosystem that is balanced and complete.

Evolutionary Theory

The central theme of evolution is that organisms acquire different features over time as a result 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 an organism could develop according to its own needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy, as well as Jean-Baptiste Lamarck (1844-1829), who suggested that the use or absence of traits can cause changes that can be passed on to future generations.

In the 1930s & 1940s, concepts from various areas, including genetics, natural selection and particulate inheritance, were brought together to form a contemporary synthesis of evolution theory. This describes how evolution occurs by the variation in genes within a population and how these variants change with time due to natural selection. This model, which encompasses mutations, genetic drift, gene flow and sexual selection, can be mathematically described.

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

Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking throughout all aspects of biology. In a recent study conducted by Grunspan and colleagues. It was demonstrated that teaching students about the evidence for evolution increased their understanding of evolution during the course of a college biology. For more information on how to teach about evolution, please look up The Evolutionary Potential of all Areas of Biology and 무료에볼루션 Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education.

Evolution in Action

Scientists have traditionally studied evolution through looking back in the past, analyzing fossils and comparing species. They also study living organisms. However, evolution isn't something that occurred in the past; it's an ongoing process, taking place today. Bacteria mutate and resist antibiotics, viruses evolve and escape new drugs and animals change their behavior to the changing climate. The changes that result are often evident.

However, it wasn't until late 1980s that biologists understood that natural selection can be observed in action as well. The key is that various traits confer different rates of survival and reproduction (differential fitness), and can be passed down from one generation to the next.

In the past, if one particular allele - the genetic sequence that controls coloration - was present in a group of interbreeding organisms, it could quickly become more prevalent than the other alleles. As time passes, that could mean 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.

Monitoring evolutionary changes in action is easier when a particular species has a fast generation turnover like bacteria. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples from each population are taken regularly and more than 500.000 generations have passed.

Lenski's research has revealed that a mutation can dramatically alter the efficiency with which a population reproduces and, consequently the rate at which it changes. It also proves that evolution takes time--a fact that many are unable to accept.

Microevolution can also be seen in the fact that mosquito genes for resistance to pesticides are more prevalent in areas where insecticides have been used. Pesticides create an exclusive pressure that favors those with resistant genotypes.

The rapid pace at which evolution takes place has led to a growing recognition of its importance in a world shaped by human activity, including climate change, pollution, and the loss of habitats that hinder the species from adapting. Understanding the evolution process will aid you in making better decisions about the future of our planet and its inhabitants.