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Evolution

Mechanisms and processes

Adaptation Genetic drift Gene flow Mutation Natural selection Speciation

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Evolutionary biology fields

Cladistics Ecological genetics Evolutionary development Human evolution Molecular evolution Phylogenetics Population genetics

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A group of organisms is said to have common descent if they have a common ancestor. Foundations of modern biology There are five unifying principles eVolution is the third Album by eLDee, it was due to be released in 2008 An adaptation is a characteristic of an Organism that has been favored by Natural selection and In Population genetics, genetic drift is the accumulation of random events that change the makeup of a gene pool slightly but often compound over time In Population genetics, gene flow (also known as gene migration) is the transfer of Alleles of Genes from one Population to another In biology mutations are changes to the Nucleotide sequence of the Genetic material of an organism Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of Speciation is the Evolutionary process by which new biological Species arise The wide range of evidence of common descent of living things strongly indicates the occurrence of Evolution and provides a wealth of information on the natural processes Although evidence of early Life is scarce and often difficult to interpret it appears that life appeared on Earth relatively soon (on the Geologic time scale) after Evolutionary thought, the idea that species change over time has roots in antiquity in the ideas of the Greeks, Romans, Chinese and Muslims theory of transmutation had early origins in the speculations and hypotheses of Erasmus Darwin, and Jean-Baptiste Lamarck. Objections to evolution have been raised ever since various evolutionary ideas came to prominence around the start of the nineteenth century Cladistics is the hierarchical classification of Species based on evolutionary ancestry Ecological genetics is the study of Genetics in the context of the interactions among organisms and between the organisms and their environment Evolutionary developmental biology ( evolution of development or informally evo-devo) is a field of Biology that compares the developmental processes Human evolution, or anthropogenesis, is the part of biological Evolution concerning the emergence of Homo sapiens as a distinct Species Molecular evolution is the process of evolution at the scale of DNA, RNA, and Proteins Molecular evolution emerged as a scientific field in the 1960s as Population genetics is the study of the Allele frequency distribution and change under the influence of the four evolutionary forces Natural selection, Genetic An ancestor is a Parent or ( recursively) the parent of an ancestor (i In modern biology, it is generally accepted that all living organisms on Earth are descended from a common ancestor or ancestral gene pool. Foundations of modern biology There are five unifying principles EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 ^[1]

A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin in his book On the Origin of Species (1859), and later in The Descent of Man (1871). eVolution is the third Album by eLDee, it was due to be released in 2008 Charles Robert Darwin (February 12 1809 &ndash April 19 1882 was an English naturalist, who realised and demonstrated that all Species of life Charles Darwin 's On the Origin of Species (published 24 November 1859) is a seminal work in Scientific literature and arguably the The Descent of Man and Selection in Relation to Sex is a book on Evolutionary theory by English naturalist Charles Darwin, first 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 last universal ancestor ( LUA) also called the last universal common ancestor ( LUCA) the cenancestor or "number one" In Genetics, 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 This timeline of the evolution of life outlines the major events in the development 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). A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic

Contents 1 History 2 Evidence of universal common descent 2.1 Common biochemistry and genetic code 2.1.1 Selectively neutral similarities 2.1.2 Other similarities 2.2 Phylogenetic trees 3 Illustrations of common descent 3.1 Artificial selection 3.1.1 Dog breeding 3.1.2 Wild cabbage 3.2 Natural selection 3.2.1 Darwin's finches 4 References 5 External links

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. Evolutionary thought, the idea that species change over time has roots in antiquity in the ideas of the Greeks, Romans, Chinese and Muslims Pierre-Louis Moreau de Maupertuis ( July 17, 1698 &ndash July 27, 1759) was a French Mathematician, Philosopher Specifically:

"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 (ɪmanuəl kant 22 April 1724 12 February 1804 was an 18th-century German Philosopher from the Prussian city of Königsberg

Charles Darwin's grandfather, Erasmus Darwin, hypothesized in 1795 that all warm-blooded animals were descended from a single "living filament":

". Erasmus Darwin (12 December 1731&ndash18 April 1802 was 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 recognized 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. Special creation describes a mechanism for producing life on earth that is promoted by "special creationists" following an agenda known as "special creationism" "

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".

Evidence of universal common descent

Main article: Evidence of common descent

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. The wide range of evidence of common descent of living things strongly indicates the occurrence of Evolution and provides a wealth of information on the natural processes Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known 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 genetic code is the set of rules by which information encoded in genetic material ( DNA or RNA sequences is translated into Proteins 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]

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. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this 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. The genetic code is the set of rules by which information encoded in genetic material ( DNA or RNA sequences is translated into Proteins

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. Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this 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. Convergent evolution describes the acquisition of the same biological trait in unrelated lineages

Phylogenetic trees

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. See also Tree of life (disambiguation for other meanings of the Tree of Life A phylogenetic tree, also called an evolutionary tree, is a tree showing the Evolutionary relationships among various biological Species or other 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]

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. Artificial selection is the intentional breeding for certain traits or combinations of traits over others and is synonymous with " Selective breeding " 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. The grey wolf or gray wolf ( Canis lupus) also known as the timber wolf or simply wolf, is a Mammal of the order Carnivora Brassica oleracea or Wild Mustard, is a species of Brassica native to coastal southern and western Europe, where its tolerance 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.

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 (Chihuahueño is the smallest breed of Dog in the world and is named after the state of Chihuahua in Mexico. A mixed-breed dog (also called a mutt, mongrel, tyke, cur, bitzer or random-bred dog) is a Dog that has The Great Dane, Danish Hound, or German Mastiff, is a breed of Domestic dog ( Dog breeding is the practice of mating selected specimens with the intent to maintain or produce specific qualities and characteristics The dog ( Canis lupus familiaris) is a domesticated Subspecies of the gray wolf, a Mammal of the Canidae family of the order 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. The grey wolf or gray wolf ( Canis lupus) also known as the timber wolf or simply wolf, is a Mammal of the order Carnivora To see the wide range of difference between the many breeds of dogs compare the Chihuahua, Great Dane, Basset Hound, Pug, and Poodle. The (Chihuahueño is the smallest breed of Dog in the world and is named after the state of Chihuahua in Mexico. The Great Dane, Danish Hound, or German Mastiff, is a breed of Domestic dog ( The Basset Hound is a short-legged breed of Dog of the Hound family The Pug is a small breed of Dog with a wrinkly short muzzled face. Also compare this enormous diversity with the relative uniformity of wild wolves.

Wild cabbage

Main article: Brassica oleracea

Early farmers cultivated many popular vegetables from the Brassica oleracea (common name wild cabbage) by artificially selecting for certain attributes. Brassica oleracea or Wild Mustard, is a species of Brassica native to coastal southern and western Europe, where its tolerance Brassica oleracea or Wild Mustard, is a species of Brassica native to coastal southern and western Europe, where its tolerance Common vegetables such as cabbage, kale, broccoli, cauliflower, kohlrabi and Brussels sprouts are all descendants of the wild cabbage plant. The cabbage ( Brassica oleracea var capitata) is a leafy garden plant of the Family Brassicaceae (or Cruciferae used as a Kale or Borecole is a form of Cabbage ( Brassica oleracea Acephala Group) green in color in which the central leaves do not Broccoli is a plant of the Cabbage family Brassicaceae (formerly Cruciferae Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. Kohlrabi ( German Turnip) ( Brassica oleracea Gongylodes Group is a low stout Cultivar of the Cabbage that will grow almost anywhere This article is about the plant For the pencil game see Sprouts (game. ^[4] Brussels sprouts were created by artificially selecting for large bud size. In Botany, a bud is an undeveloped or embryonic Shoot and normally occurs in the Axil of a Leaf or at the tip of the stem Broccoli was bred by selecting for large flower stalks. A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also Cabbage was created by selecting for short petioles. In Botany, the petiole is the small stalk attaching the Leaf blade to the stem. Kale was bred by selecting for large leaves. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis.

Natural selection

Main article: natural selection

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. Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of

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. Darwin's finches (also known as the Galápagos Finches) are 13 or 14 different closely related Species of Finches that Charles Darwin collected Darwin's finches (also known as the Galápagos Finches) are 13 or 14 different closely related Species of Finches that Charles Darwin collected The beak of each species is suited to its preferred food, suggesting that beak shapes evolved by natural selection. Anatomy Stegosaurus --> Beaks can vary significantly in size and shape from species to species In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of 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. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described 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. Bird migration refers to the regular seasonal journeys undertaken by many species of Birds Bird movements include those made in response to changes in food availability An adaptation is a characteristic of an Organism that has been favored by Natural selection and Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of

References

External links

• 29+ Evidences for Macroevolution: the Scientific Case for Common Descent
• The Tree of Life Web Project

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