Evidence of common descent Wikipedia. Evidence of common descent of livingorganisms has been discovered by scientists researching in a variety of disciplines over many decades, demonstrating the common descent of all life on Earth developing from a last universal common ancestor. This evidence constructs the theoretical framework on which evolutionary theory rests, demonstrates that evolution does occur, and is able to show the natural processes that led to the emergence of Earths biodiversity. Additionally, this evidence supports the modern evolutionary synthesisthe current scientific theory that explains how and why life changes over time. Evolutionary biologists document evidence of common descent by developing testable predictions, testing hypotheses, and constructing theories that illustrate and describe its causes. Comparison of the DNA genetic sequences of organisms has revealed that organisms that are phylogenetically close have a higher degree of DNA sequence similarity than organisms that are phylogenetically distant. Genetic fragments such as pseudogenes, regions of DNA that are orthologous to a gene in a related organism, but are no longer active and appear to be undergoing a steady process of degeneration from cumulative mutations support common descent alongside the universal biochemical organization and molecular variance patterns found in all organisms. Additional genetic information conclusively supports the relatedness of life and has allowed scientists since the discovery of DNA to develop phylogenetic trees a construction of organisms evolutionary relatedness. It has also led to the development of molecular clock techniques to date taxon divergence times and to calibrate these with the fossil record. Fossils are important for estimating when various lineages developed in geologic time. As fossilization is an uncommon occurrence, usually requiring hard body parts and death near a site where sediments are being deposited, the fossil record only provides sparse and intermittent information about the evolution of life. Program De Facut Stampile Forum. The origin and evolution of the wheat group the genera Aegilops, Amblyopyrum, and Triticum in the wild and under cultivation is reviewed. The diploid species. International Business Machines Corp. Stock IBM news, historical stock charts, analyst ratings, financials, and todays International Business Machines Corp. MIDI-SYNC.png' alt='Evolution Uc 33 Drivers' title='Evolution Uc 33 Drivers' />It looks like youre trying to find a page that may have been moved or not longer exists. Please try using our search function to find your content. Are you looking. Evidence of organisms prior to the development of hard body parts such as shells, bones and teeth is especially scarce, but exists in the form of ancient microfossils, as well as impressions of various soft bodied organisms. The comparative study of the anatomy of groups of animals shows structural features that are fundamentally similar homologous, demonstrating phylogenetic and ancestral relationships with other organisms, most especially when compared with fossils of ancient extinct organisms. Vestigial structures and comparisons in embryonic development are largely a contributing factor in anatomical resemblance in concordance with common descent. Since metabolic processes do not leave fossils, research into the evolution of the basic cellular processes is done largely by comparison of existing organisms physiology and biochemistry. Many lineages diverged at different stages of development, so it is possible to determine when certain metabolic processes appeared by comparing the traits of the descendants of a common ancestor. Further evidence comes from the field of biogeography because evolution with common descent provides the best and most thorough explanation for a variety of facts concerning the geographical distribution of plants and animals across the world. This is especially obvious in the field of insular biogeography. Combined with the well established geological theory of plate tectonics, common descent provides a way to combine facts about the current distribution of species with evidence from the fossil record to provide a logically consistent explanation of how the distribution of living organisms has changed over time. The development and spread of antibiotic resistant bacteria provides evidence that evolution due to natural selection is an ongoing process in the natural world. Natural selection is ubiquitous in all research pertaining to evolution, taking note of the fact that all of the following examples in each section of the article document the process. Alongside this are observed instances of the separation of populations of species into sets of new species speciation. Speciation has been observed directly and indirectly in the lab and in nature. Multiple forms of such have been described and documented as examples for individual modes of speciation. Furthermore, evidence of common descent extends from direct laboratory experimentation with the selective breeding of organismshistorically and currentlyand other controlled experiments involving many of the topics in the article. This article summarizes the varying disciplines that provide the evidence for evolution and the common descent of all life on Earth, accompanied by numerous and specialized examples, indicating a compelling concordance of evidence. Evidence from comparative physiology and biochemistryeditGeneticseditOne of the strongest evidences for common descent comes from the study of gene sequences. Comparative sequence analysis examines the relationship between the DNA sequences of different species,1 producing several lines of evidence that confirm Darwins original hypothesis of common descent. If the hypothesis of common descent is true, then species that share a common ancestor inherited that ancestors DNA sequence, as well as mutations unique to that ancestor. More closely related species have a greater fraction of identical sequence and shared substitutions compared to more distantly related species. The simplest and most powerful evidence is provided by phylogenetic reconstruction. Such reconstructions, especially when done using slowly evolving protein sequences, are often quite robust and can be used to reconstruct a great deal of the evolutionary history of modern organisms and even in some instances of the evolutionary history of extinct organisms, such as the recovered gene sequences of mammoths or Neanderthals. These reconstructed phylogenies recapitulate the relationships established through morphological and biochemical studies. The most detailed reconstructions have been performed on the basis of the mitochondrial genomes shared by all eukaryotic organisms, which are short and easy to sequence the broadest reconstructions have been performed either using the sequences of a few very ancient proteins or by using ribosomal RNA sequencecitation needed. Phylogenetic relationships also extend to a wide variety of nonfunctional sequence elements, including repeats, transposons, pseudogenes, and mutations in protein coding sequences that do not result in changes in amino acid sequence. While a minority of these elements might later be found to harbor function, in aggregate they demonstrate that identity must be the product of common descent rather than common functioncitation needed. Universal biochemical organisation and molecular variance patternseditAll known extant surviving organisms are based on the same biochemical processes genetic information encoded as nucleic acid DNA, or RNA for many viruses, transcribed into RNA, then translated into proteins that is, polymers of amino acids by highly conserved ribosomes. Perhaps most tellingly, the Genetic Code the translation table between DNA and amino acids is the same for almost every organism, meaning that a piece of DNA in a bacterium codes for the same amino acid as in a human cell. ATP is used as energy currency by all extant life. A deeper understanding of developmental biology shows that common morphology is, in fact, the product of shared genetic elements. For example, although camera like eyes are believed to have evolved independently on many separate occasions,3 they share a common set of light sensing proteins opsins, suggesting a common point of origin for all sighted creatures. Another noteworthy example is the familiar vertebrate body plan, whose structure is controlled by the homeobox Hox family of genes.