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Encyclopedia > Common descent
Part of the Biology series on
Evolution
Mechanisms and processes

Adaptation
Genetic drift
Gene flow
Mutation
Selection
Speciation This article or section does not cite any references or sources. ... This article is about evolution in biology. ... Image File history File links Tree_of_life. ... A biological adaptation is an anatomical structure, physiological process or behavioral trait of an organism that has evolved over a period of time by the process of natural selection such that it increases the expected long-term reproductive success of the organism. ... In population genetics, genetic drift is the statistical effect that results from the influence that chance has on the success of alleles (variants of a gene). ... In population genetics, gene flow (also known as gene migration) is the transfer of alleles of genes from one population to another. ... It has been suggested that mutant be merged into this article or section. ... Selection is hierachically classified into natural and artificial selection. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the evolutionary process by which new biological species arise. ...

Research and history

Evidence
History
Modern synthesis
Social effect / Objections While on board HMS Beagle, Charles Darwin collected numerous specimens, many new to science, which supported his later theory of evolution by natural selection. ... Evolutionary thought has roots in antiquity as philosophical ideas conceived during the Ancient Greek and Roman eras. ... This article or section does not cite any references or sources. ... The theory of transmutation had early origins in the speculations and hypotheses of Erasmus Darwin, and Jean-Baptiste Lamarck. ... This ichthys fish parody reflects the view that Christianity and Darwinian evolution are in conflict, but that Christian TRUTH will triumph. ...

Evolutionary biology fields

Ecological genetics
Evolutionary development
Human evolution
Molecular evolution
Phylogenetics
Population genetics
Evolutionary biology is a subfield of biology concerned with the origin and descent of species, as well as their change, multiplication, and diversity over time. ... Ecological genetics is the study of genetics (itself a field of biology) from an ecological perspective. ... Evolutionary developmental biology (evolution of development or informally, evo-devo) is a field of biology that compares the developmental processes of different animals in an attempt to determine the ancestral relationship between organisms and how developmental processes evolved. ... This article or section does not adequately cite its references or sources. ... Molecular evolution is the process of the genetic material in populations of organisms changing over time. ... Phylogenetic groups, or taxa, can be monophyletic, paraphyletic, or polyphyletic. ... Population genetics is the study of the distribution of and change in allele frequencies under the influence of the four evolutionary forces: natural selection, genetic drift, mutation, and migration. ...

Biology Portal · v  d  e 

A group of organisms is said to have common descent if they have a common ancestor. In modern biology, it is generally accepted that all living organisms on Earth are descended from a common ancestor or ancestral gene pool.[1] An ancestor is a parent or (recursively) the parent of an ancestor (i. ... This article or section does not cite any references or sources. ... This article or section does not cite any references or sources. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ...


A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin in his book The Origin of Species (1859), and later in The Descent of Man (1871). This theory is now generally accepted by biologists, and the last universal common ancestor (LUCA or LUA), that is, the most recent common ancestor of all currently living organisms, is believed to have appeared about 3.9 billion years ago. The theory of a common ancestor between all organisms is one of the principles of evolution, although for single cell organisms and viruses, single phylogeny is disputed (see: origin of life). This article is about evolution in biology. ... For other people of the same surname, and places and things named after Charles Darwin, see Darwin. ... British naturalist Charles Darwins book, The Origin of Species, is one of the pivotal works in scientific literature and arguably the pre-eminent work in biology. ... The Descent of Man and Selection in Relation to Sex by British naturalist Charles Darwin was first published in 1871. ... Last universal ancestor (LUA), the hypothetical latest living organism from which all currently living organisms descend. ... The most recent common ancestor (MRCA) of any set of organisms is the most recent individual from which all organisms in the group are directly descended. ... This timeline of the evolution of life outlines the major events in the development of life on the planet Earth. ... A cluster of Escherichia coli bacteria magnified 10,000 times. ... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (from the Latin noun virus, meaning toxin or poison) is a microscopic particle (ranging in size from 20 - 300 nm) that can infect the... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... This article does not adequately cite its references or sources. ...

Contents

History

See also: History of evolutionary thought

The first suggestion that all organisms may have had a common ancestor and diverged through random variation and natural selection was made in 1745 by the French mathematician and scientist Pierre-Louis Moreau de Maupertuis (1698-1759) in his work Vénus physique. Specifically: Evolutionary thought has roots in antiquity as philosophical ideas conceived during the Ancient Greek and Roman eras. ... Pierre Louis Maupertuis, here wearing lapmudes or a fur coat from his Lapland expedition. ...

"Could one not say that, in the fortuitous combinations of the productions of nature, as there must be some characterized by a certain relation of fitness which are able to subsist, it is not to be wondered at that this fitness is present in all the species that are currently in existence? Chance, one would say, produced an innumerable multitude of individuals; a small number found themselves constructed in such a manner that the parts of the animal were able to satisfy its needs; in another infinitely greater number, there was neither fitness nor order: all of these latter have perished. Animals lacking a mouth could not live; others lacking reproductive organs could not perpetuate themselves... The species we see today are but the smallest part of what blind destiny has produced..."

In 1790, Immanuel Kant (Königsberg (Kaliningrad) 1724 - 1804), in his Kritik der Urtheilskraft, states that the analogy of animal forms implies a common original type and thus a common parent. Immanuel Kant (22 April 1724 – 12 February 1804), was a German philosopher from Königsberg in East Prussia (now Kaliningrad, Russia). ...


Charles Darwin's grandfather, Erasmus Darwin, hypothesized in 1795 that all warm-blooded animals were descended from a single "living filament": Stone-cast bust of Erasmus Darwin, by W. J. Coffee, c 1795 Erasmus Darwin (12 December 1731 – 18 April 1802), an English physician, natural philosopher, physiologist, inventor and poet. ...

"...would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE endued with animality...?" (Zoonomia, 1795, section 39, "Generation")

In 1859, Charles Darwin's The Origin of Species was published. The views about common descent expressed therein vary between suggesting that there was a single "first creature" to allowing that there may have been more than one. Here are the relevant quotations from the Conclusion:

"[P]robably all of the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed."
"The whole history of the world, as at present known, ... will hereafter be recognised as a mere fragment of time, compared with the ages which have elapsed since the first creature, the progenitor of innumerable extinct and living descendants, was created."
"When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, they seem to me to become ennobled."

The famous closing sentence describes the "grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one." The phrase "one form" here seems to hark back to the phrase "some few beings"; in any case, the choice of words is remarkable for its consistency with recent ideas about there having been a single ancestral "genetic pool". Special creation describes a mechanism for producing life on earth that is promoted by special creationists following an agenda known as special creationism. In general, special creation is a type of belief about the origin of life on earth. ...


Evidence of universal common descent

See also: evidence of evolution

While on board HMS Beagle, Charles Darwin collected numerous specimens, many new to science, which supported his later theory of evolution by natural selection. ...

Common biochemistry and genetic code

All known forms of life are based on the same fundamental biochemical organisation: genetic information encoded in DNA, transcribed into RNA, through the effect of protein- and RNA-enzymes, then translated into proteins by (highly similar) ribosomes, with ATP, NADH and others as energy currencies, etc. Furthermore, the genetic code (the "translation table" according to which DNA information is translated into proteins) is nearly identical for all known lifeforms, from bacteria to humans, with minor local differences. The universality of this code is generally regarded by biologists as definitive evidence in favor of the theory of universal common descent. Analysis of the small differences in the genetic code has also provided support for universal common descent.[2] The structure of part of a DNA double helix Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living organisms. ... A series of codons in a short RNA molecule. ...


Selectively neutral similarities

Similarities which have no relevance to evolution and therefore cannot be explained by convergence, tend to be very compelling support for the universal common descent theory.


Such evidence has come from two domains: amino acid sequences and DNA sequences. Proteins with the same 3-d structure need not have identical amino acid sequences; any irrelevant similarity between the sequences is evidence for common descent. In certain cases, there are several codons (DNA triplets) that code for the same amino acid. Thus, if two species use the same codon at the same place to specify an amino acid that can be represented by more than one codon, that is evidence for recency of a common ancestor. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Phenylalanine is one of the standard amino acids. ... RNA codons. ...


Other similarities

The universality of many aspects of cellular life is often pointed to as supportive evidence to the more compelling evidence listed above. These similarities include the energy carrier ATP, and the fact that all amino acids found in proteins are left-handed. It is possible that these similarities resulted because of the laws of physics and chemistry, rather than universal common descent and therefore resulted in convergent evolution. Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... Phenylalanine is one of the standard amino acids. ... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ...


Phylogenetic trees

A phylogenetic tree based on rRNA genes.
A phylogenetic tree based on rRNA genes.
See also: Tree of life (science)

Another important piece of evidence is that it is possible to construct detailed phylogenetic trees (that is, "genealogic trees" of species) mapping out the proposed divisions and common ancestors of all living species. Traditionally, these trees have been built using morphological methods (based on appearance, embryology, etc). Recently, it has been possible to construct these trees using molecular data (based on similarities and differences between genetic and protein sequences). Crucially, all these methods produce essentially similar results, despite the fact that most genetic variation has no influence over external morphology. The fact that phylogenetic trees based on different types of information agree with each other is strong evidence of a real underlying phylogeny - that is, common descent.[3] Image File history File links Phylogenetic_tree. ... Image File history File links Phylogenetic_tree. ... Darwins work was originally entitled Phylogeny via Oogeny. ... A phylogenetic tree is a tree showing the evolutionary interrelationships among various species or other entities that are believed to have a common ancestor. ...


Illustrations of common descent

Artificial selection

Artificial selection offers remarkable examples of the amount of diversity that can exist between individuals sharing a late common ancestor. To perform artificial selection, one begins with a particular species (following examples include wolves and wild cabbage) and then, at every generation, only allow certain individuals to reproduce, based on the degree to which they exhibit certain desirable characteristics. In time, it is expected that these characteristics become increasingly well-developed in successive generations. Many examples of artificial selection, like the ones below, occurred without the guidance of modern scientific insight. This Chihuahua mix and Great Dane show the wide range of dog breed sizes created using artificial selection. ... Binomial name Canis lupus Linnaeus, 1758 Wolf redirects here. ... Binomial name Brassica oleracea L. Brassica oleracea or Wild Cabbage, is a species of Brassica native to coastal southern and western Europe, where its tolerance of salt and lime but intolerance of competition from other plants typically restricts its natural occurrence to limestone sea cliffs. ...

This Chihuahua mix and Great Dane show the wide range of dog breed sizes

Image File history File links IMG013biglittledogFX_wb. ... Image File history File links IMG013biglittledogFX_wb. ... This article or section does not cite any references or sources. ... This small dog of unknown parentage may be part Chihuahua or Miniature Pinscher. ... The Great Dane is a breed of dog known for its large size and gentle personality. ...

Dog breeding
Main article: dog breeding

An obvious example of the power of artificial selection is the diversity found in various breed in domesticated dogs. The various breeds of dogs all share common ancestry (being all ultimately descended from wolves) but were domesticated by humans and then selectively bred in order to enhance various features such as coat color and length or body size. To see the wide range of difference between the many breeds of dogs compare the Chihuahua, Great Dane, Basset Hound, Pug, and Poodle. Also compare this enormous diversity with the relative uniformity of wild wolves. Dog breeding is the vocation of mating carefully selected specimens to produce specific qualities and characteristics. ... Trinomial name Canis lupus familiaris The dog is a mammal in the order Carnivora. ... Binomial name Canis lupus Linnaeus, 1758 Wolf redirects here. ... This article or section does not cite any references or sources. ... The Great Dane is a breed of dog known for its large size and gentle personality. ... This article does not cite any references or sources. ... For the song by The Smashing Pumpkins, see Adore. ... The Poodle is a breed of dog. ...


Wild cabbage
Wild Cabbage plant
Wild Cabbage plant
Main article: Brassica oleracea

Early farmers cultivated many popular vegetables from the Brassica oleracea (common name wild cabbage) by artificially selecting for certain attributes. Common vegetables such as cabbage, kale, broccoli, cauliflower, kohlrabi and Brussels sprouts are all descendants of the wild cabbage plant.[4] Brussels sprouts were created by artificially selecting for large bud size. Broccoli was bred by selecting for large flower stalks. Cabbage was created by selecting for short petioles. Kale was bred by selecting for large leaves. Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2048 × 1536 pixel, file size: 827 KB, MIME type: image/jpeg) Brassica oleracea (Wild Cabbage) - naturalised population growing on seacliffs below a mediaeval monastery at Tynemouth, Northumberland, UK File links The following pages on... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2048 × 1536 pixel, file size: 827 KB, MIME type: image/jpeg) Brassica oleracea (Wild Cabbage) - naturalised population growing on seacliffs below a mediaeval monastery at Tynemouth, Northumberland, UK File links The following pages on... Binomial name Brassica oleracea L. See also cabbage Brassica oleracea or Wild Cabbage, is a species of Brassica native to coastal southern and western Europe, where its resistance to salt and lime but intolerance of competition from other plants typically restricts its natural occurrence to limestone sea cliffs. ... Binomial name Brassica oleracea L. See also cabbage Brassica oleracea or Wild Cabbage, is a species of Brassica native to coastal southern and western Europe, where its resistance to salt and lime but intolerance of competition from other plants typically restricts its natural occurrence to limestone sea cliffs. ... Percentages are relative to US recommendations for adults. ... Kale (also called Borecole) is a form of cabbage (Brassica oleracea Acephala Group), green in color, in which the central leaves do not form a head. ... Broccoli is a plant of the Cabbage family, Brassicaceae (formerly Cruciferae). ... Percentages are relative to US recommendations for adults. ... Kohlrabi (Brassica oleracea Gongylodes Group) is a low, stout cultivar of the cabbage which has been selected for its swollen, nearly spherical, Sputnik-like shape. ... Cultivar Group Brassica oleracea Gemmifera Group The Brussels sprout (Brassica oleracea Gemmifera Group) is a cultivar group of cabbage cultivated for its small (typically 2. ... Flower buds have not yet bloomed into a full-size flower. ... A Phalaenopsis flower Rudbeckia fulgida A flower, (<Old French flo(u)r<Latin florem<flos), also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). ... Leaf of Dog Rose (Rosa canina), showing the petiole and two leafy stipules In botany, the petiole is the small stalk attaching the leaf blade to the stem. ... “Foliage” redirects here. ...


Natural selection

Main article: natural selection
Darwin's finches
Darwin's finches

Natural selection is the evolutionary process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms, and unfavorable traits that are heritable become less common. Darwins illustrations of beak variation in the finches of the Galápagos Islands, which hold 13 closely related species that differ most markedly in the shape of their beaks. ... Image File history File links Darwin's_finches. ... Image File history File links Darwin's_finches. ...


Darwin's finches
Main article: Darwin's finches

During Darwin's studies on the Galápagos Islands, Darwin observed 13 species of finches that are closely related and differ most markedly in the shape of their beaks. The beak of each species is suited to its preferred food, suggesting that beak shapes evolved by natural selection. Large beaks were found on the islands where the primary source of food for the finches is nuts and therefore the large beaks allowed the birds to be better equipped for opening the nuts and staying well nourished. Slender beaks were found on the finches which found insects to be the best source of food on the island they inhabited; their slender beaks allowed the birds to be better equipped for pulling out the insects from their tiny hiding places. The finch is also found on the main land and it is thought that they migrated to the islands and began adapting to their environment through natural selection. Darwins finches (also known as the Galápagos Finches) are 13 or 14 different closely related species of finches Charles Darwin discovered on the Galápagos Islands, 13 reside on the Galápagos Islands, one on the Cocos Islands. ... Orthographic projection centred over the Galápagos. ... Darwins finches (also known as the Galápagos Finches) are 13 or 14 different closely related species of finches Charles Darwin discovered on the Galápagos Islands, 13 reside on the Galápagos Islands, one on the Cocos Islands. ... The beak—otherwise known as the bill or rostrum—is an external anatomical structure which serves as the mouth in some animals. ... In biology, a species is one of the basic units of biodiversity. ... Darwins illustrations of beak variation in the finches of the Galápagos Islands, which hold 13 closely related species that differ most markedly in the shape of their beaks. ... Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea (mantids) Isoptera (termites) Zoraptera Grylloblattodea Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, crickets... Migration occurs when living things move from one biome to another. ... A biological adaptation is an anatomical structure, physiological process or behavioral trait of an organism that has evolved over a period of time by the process of natural selection such that it increases the expected long-term reproductive success of the organism. ... Darwins illustrations of beak variation in the finches of the Galápagos Islands, which hold 13 closely related species that differ most markedly in the shape of their beaks. ...


References

  1. ^ The earliest life-like forms probably exchanged genetic material laterally in a manner that is analogous to lateral gene transfer amongst bacteria. For this and other reasons, the most recent common ancestor may have been a genetic pool rather than an organism.
  2. ^ Robin Knight et. al. (2001). "Rewiring the keyboard: evolvability of the genetic code". Nature Reviews - Genetics 2 (1): 49-58. PMID 11253070. 
  3. ^ Theobald, Douglas, 29+ Evidences for Macroevolution, Section 1.3
  4. ^ Biology of Plants (7th edition) by Raven, Evert, and Eichhorn, 2005, states that these vegetables were "all produced from a single species of plant (Brassica oleraca), a member of the mustard family."

Horizontal gene transfer (HGT), also Lateral gene transfer (LGT), is any process in which an organism transfers genetic material to another cell that is not its offspring. ...

External links


  Results from FactBites:
 
Common descent - definition of Common descent in Encyclopedia (890 words)
In biology, the theory of universal common descent proposes that all organisms on Earth are descended from a common ancestor or ancestral gene pool.andsup1
A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin in his book The Origin of Species (1859), and later in The Descent of Man (1871).
One such tree showing the paths of descent from a common ancestor is depicted in the article on phylogenetic trees.
  More results at FactBites »

 
 

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