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The Academy's Evolution Site

The concept of biological evolution is among the most central concepts in biology. The Academies have been for a long time involved in helping people who are interested in science comprehend the theory of evolution and how it influences every area of scientific inquiry.

This site provides teachers, students and general readers with a wide range of educational resources on evolution. It contains the most important video clips from NOVA and 에볼루션 코리아 WGBH's science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is an emblem of love and unity in many cultures. It also has practical uses, like providing a framework to understand the evolution of species and how they respond to changes in the environment.

The earliest attempts to depict the biological world focused on the classification of species into distinct categories that were identified by their physical and metabolic characteristics1. These methods, based on the sampling of various parts of living organisms, or short DNA fragments, greatly increased the variety of organisms that could be included in a tree of life2. These trees are mostly populated by eukaryotes, 에볼루션사이트 and the diversity of bacterial species is greatly underrepresented3,4.

In avoiding the necessity of direct observation and experimentation, genetic techniques have allowed us to depict the Tree of Life in a more precise way. Particularly, molecular methods allow us to build trees by using sequenced markers, such as the small subunit ribosomal RNA gene.

Despite the rapid growth of the Tree of Life through genome sequencing, much biodiversity still remains to be discovered. This is especially true of microorganisms, which can be difficult to cultivate and are often only present in a single specimen5. A recent analysis of all genomes resulted in a rough draft of a Tree of Life. This includes a large number of archaea, bacteria, and other organisms that have not yet been isolated or 에볼루션 코리아 their diversity is not well understood6.

This expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if certain habitats need special protection. This information can be utilized in a variety of ways, from identifying the most effective treatments to fight disease to improving crop yields. This information is also useful in conservation efforts. It helps biologists determine those areas that are most likely contain cryptic species that could have important metabolic functions that could be vulnerable to anthropogenic change. While funding to protect biodiversity are essential, the best way to conserve the world's biodiversity is to equip more people in developing nations with the necessary knowledge to act locally and support conservation.

Phylogeny

A phylogeny is also known as an evolutionary tree, shows the relationships between various groups of organisms. Scientists can build a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic groups using molecular data and morphological similarities or differences. Phylogeny is essential in understanding evolution, biodiversity and genetics.

A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms that have similar traits and have evolved from a common ancestor. These shared traits could be analogous, or homologous. Homologous traits are identical in their evolutionary roots and analogous traits appear similar but do not have the same origins. Scientists arrange similar traits into a grouping referred to as a Clade. All organisms in a group have a common characteristic, like amniotic egg production. They all came from an ancestor that had these eggs. The clades then join to form a phylogenetic branch to determine the organisms with the closest relationship.

Scientists make use of DNA or RNA molecular information to build a phylogenetic chart that is more accurate and precise. This information is more precise and gives evidence of the evolution of an organism. Researchers can use Molecular Data to calculate the age of evolution of organisms and determine how many organisms have a common ancestor.

The phylogenetic relationships between organisms can be affected by a variety of factors, including phenotypic plasticity an aspect of behavior that alters in response to specific environmental conditions. This can make a trait appear more similar to one species than to another which can obscure the phylogenetic signal. However, this problem can be reduced by the use of methods such as cladistics that include a mix of analogous and homologous features into the tree.

In addition, phylogenetics can help predict the duration and rate of speciation. This information can aid conservation biologists to decide the species they should safeguard from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will result in a complete and balanced ecosystem.

Evolutionary Theory

The main idea behind evolution is that organisms change over time as a result of their interactions with their environment. Many theories of evolution have been proposed by a wide range of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly in accordance with its needs and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits can cause changes that could be passed on to offspring.

In the 1930s & 1940s, theories from various fields, such as genetics, natural selection and particulate inheritance, were brought together to form a modern synthesis of evolution theory. This explains how evolution occurs by the variation of genes in a population and how these variants change over time as a result of natural selection. This model, which is known as genetic drift or mutation, gene flow and sexual selection, is a cornerstone of the current evolutionary biology and can be mathematically described.

Recent advances in the field of evolutionary developmental biology have revealed how variation can be introduced to a species via genetic drift, mutations and reshuffling of genes during sexual reproduction and migration between populations. These processes, as well as others, such as directionally-selected selection and erosion of genes (changes to the frequency of genotypes over time) can lead to evolution. Evolution is defined by changes in the genome over time and changes in the phenotype (the expression of genotypes within individuals).

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

Evolution in Action

Scientists have studied evolution through looking back in the past, studying fossils, and comparing species. They also observe living organisms. But evolution isn't a thing that occurred in the past; it's an ongoing process, happening today. The virus reinvents itself to avoid new medications and bacteria mutate to resist antibiotics. Animals alter their behavior in the wake of the changing environment. The results are often apparent.

It wasn't until the late 1980s when biologists began to realize that natural selection was at work. The key is that various traits confer different rates of survival and reproduction (differential fitness) and can be passed from one generation to the next.

In the past, if one particular allele - the genetic sequence that defines color in a population of interbreeding organisms, 에볼루션카지노 it could quickly become more common than all other alleles. Over time, this would mean that the number of moths that have black pigmentation could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

It is easier to track evolution when a species, such as bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, 에볼루션 바카라 has been tracking twelve populations of E.coli that are descended from a single strain. Samples from each population were taken frequently and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has demonstrated 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, a fact that is hard for some to accept.

Another example of microevolution is that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides are used. Pesticides create a selective pressure which favors those who have resistant genotypes.

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