10 Misconceptions That Your Boss May Have Concerning Evolution Site

The Academy's Evolution Site

The concept of biological evolution is among the most important concepts in biology. The Academies are committed to helping those who are interested in science learn about the theory of evolution and how it is incorporated across all areas of scientific research.

This site provides students, teachers and general readers with a wide range of learning resources about evolution. It has 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 an emblem of love and unity in many cultures. It can be used in many practical ways as well, such as providing a framework for understanding the history of species and how they react to changes in environmental conditions.

Early attempts to represent the biological world were founded on categorizing organisms on their physical and metabolic characteristics. These methods, which rely on the collection of various parts of organisms, or DNA fragments have significantly increased the diversity of a Tree of Life2. However these trees are mainly composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4.

In avoiding the necessity of direct experimentation and observation, genetic techniques have allowed us to depict the Tree of Life in a much more accurate way. Trees can be constructed using molecular techniques, such as the small-subunit ribosomal gene.

Despite the massive expansion of the Tree of Life through genome sequencing, a lot of biodiversity awaits discovery. This is particularly relevant to microorganisms that are difficult to cultivate, and are typically found in a single specimen5. Recent analysis of all genomes resulted in an initial draft of the Tree of Life. This includes a wide range 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 evaluate the biodiversity of a particular area and determine if certain habitats need special protection. This information can be utilized in a variety of ways, such as identifying new drugs, combating diseases and enhancing crops.  무료 에볼루션  is also incredibly valuable in conservation efforts. It helps biologists discover areas that are likely to have cryptic species, which may perform important metabolic functions and be vulnerable to the effects of human activity. While funds to protect biodiversity are crucial, ultimately the best way to preserve the world's biodiversity is for more people in developing countries to be empowered with the necessary knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny (also known as an evolutionary tree) depicts the relationships between different organisms. Scientists can build a phylogenetic diagram that illustrates the evolution of taxonomic categories using molecular information and morphological differences or similarities. Phylogeny is essential in understanding evolution, biodiversity and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that have evolved from common ancestors. These shared traits could be either homologous or analogous. Homologous characteristics are identical in terms of their evolutionary journey. Analogous traits might appear similar but they don't have the same ancestry. Scientists put similar traits into a grouping referred to as a Clade. For example, all of the organisms in a clade share the characteristic of having amniotic egg and evolved from a common ancestor who had eggs. The clades are then connected to form a phylogenetic branch to determine which organisms have the closest relationship to.

For a more detailed and precise phylogenetic tree scientists use molecular data from DNA or RNA to determine the connections between organisms. This data is more precise than the morphological data and gives evidence of the evolutionary background of an organism or group. The analysis of molecular data can help researchers identify the number of species who share an ancestor common to them and estimate their evolutionary age.

The phylogenetic relationships of a species can be affected by a variety of factors that include phenotypicplasticity. This is a type of behavior that changes due to unique environmental conditions. This can make a trait appear more similar to a species than another, obscuring the phylogenetic signals. However, this issue can be solved through the use of techniques such as cladistics that include a mix of homologous and analogous features into the tree.

Additionally, phylogenetics aids determine the duration and rate of speciation. This information can assist conservation biologists in making decisions about which species to safeguard from extinction. Ultimately, it is the preservation of phylogenetic diversity that will create a complete and balanced ecosystem.

Evolutionary Theory

The fundamental concept of evolution is that organisms develop various characteristics over time as a result of their interactions with their environments. Many scientists have developed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274) who believed that an organism could evolve according to its individual requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy 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 next generation.

In the 1930s and 1940s, theories from a variety of fields--including genetics, natural selection, and particulate inheritance - came together to form the modern evolutionary theory synthesis that explains how evolution happens through the variations of genes within a population, and how those variants change over time due to natural selection. This model, known as genetic drift mutation, gene flow and sexual selection, is a key element of current evolutionary biology, and can be mathematically described.

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

Students can gain a better understanding of the concept of phylogeny through incorporating evolutionary thinking throughout all aspects of biology. A recent study conducted by Grunspan and colleagues, for instance, showed that teaching about the evidence that supports evolution increased students' acceptance of evolution in a college biology class. For more information on how to teach about evolution, please read 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 by looking back, studying fossils, comparing species, and studying living organisms. Evolution is not a past event; it is a process that continues today. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior because of a changing environment. The changes that result are often easy to see.

However, it wasn't until late 1980s that biologists understood that natural selection could be observed in action as well. 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, when one particular allele, the genetic sequence that controls coloration - was present in a population of interbreeding organisms, it might quickly become more prevalent than other alleles. Over time, that would mean the number of black moths within 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 see evolution when a species, such as bacteria, has a high generation turnover. Since 1988 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 shows evolution takes time, a fact that is hard for some to accept.

Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more common in populations that have used insecticides. This is due to the fact that the use of pesticides causes a selective pressure that favors individuals who have resistant genotypes.

The rapid pace at which evolution can take place has led to a growing awareness of its significance in a world that is shaped by human activity, including climate change, pollution, and the loss of habitats that prevent many species from adjusting. Understanding the evolution process will help us make better decisions regarding the future of our planet and the life of its inhabitants.