Most recent common ancestor
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biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of Cell (biology), cells that proce ...
and
genetic genealogy Genetic genealogy is the use of genealogical DNA tests, i.e., DNA profiling and Genetic testing, DNA testing, in combination with traditional Genealogy, genealogical methods, to infer Genetic distance, genetic relationships between individuals. Th ...
, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of
organism In biology, an organism () is any life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy (biology), taxonomy into groups such as Multicellular o ...
s is the most recent individual from which all the organisms of the set are descended. The term is also used in reference to the ancestry of groups of
gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian inheritance#History, Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanin ...
s (
haplotype A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material (DNA) which is inherited from two parents. Normally these organisms have their DNA o ...
s) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such ''time to most recent common ancestor'' (''TMRCA'') estimates can be given based on DNA test results and established
mutation rate In genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, ...
s as practiced in genetic genealogy, or by reference to a non-genetic,
mathematical model A mathematical model is a description of a system using mathematical concepts and language Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Languag ...
or computer simulation. In organisms using
sexual reproduction Sexual reproduction is a type of reproduction that involves a complex Biological life cycle, life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to p ...
, the ''matrilineal MRCA'' and ''patrilineal MRCA'' are the MRCAs of a given population considering only
matrilineal Matrilineality is the tracing of kinship through the female line. It may also correlate with a social system in which each person is identified with their matriline – their mother's Lineage (anthropology), lineage – and which can in ...
and
patrilineal Patrilineality, also known as the male line, the spear side or agnatic kinship, is a common kinship system in which an individual's family membership derives from and is recorded through their father's lineage. It generally involves the inheritanc ...
descent, respectively. The MRCA of a population by definition cannot be older than either its matrilineal or its patrilineal MRCA. In the case of ''
Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedality, bipedalism and exceptional cognitive skills due to a large and complex Human brain, brain. This has enabled the development of ad ...
'', the matrilineal and patrilineal MRCA are also known as "
Mitochondrial Eve In human genetics, the Mitochondrial Eve (also ''mt-Eve, mt-MRCA'') is the Matrilineality, matrilineal most recent common ancestor (MRCA) of all world population, living humans. In other words, she is defined as the most recent woman from whom ...
" (mt-MRCA) and " Y-chromosomal Adam" (Y-MRCA) respectively. The age of the human MRCA is unknown. It is no greater than the age of either the Y-MRCA or the mt-MRCA, estimated at around 200,000 years. Unlike in pedigrees of individual humans or domesticated lineages where historical parentage is known, in the inference of relationships among species or higher groups of
taxa In biology, a taxon (back-formation from ''Taxonomy (biology), taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known ...
(
systematics Biological systematics is the study of the diversification of living forms, both past and present, and the Correlation and dependence, relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: c ...
or
phylogenetics In biology, phylogenetics (; from Greek language, Greek wikt:φυλή, φυλή/wikt:φῦλον, φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary his ...
), ancestors are not directly observable or recognizable. They are inferences based on patterns of relationship among taxa inferred in a
phylogenetic analysis In biology, phylogenetics (; from Greek language, Greek wikt:φυλή, φυλή/wikt:φῦλον, φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary his ...
of extant organisms and/or fossils. The
last universal common ancestor The last universal common ancestor (LUCA) is the most recent population from which all organisms now living on Earth share common descent—the most recent common ancestor of all current life on Earth. This includes all cellular organisms; ...
(LUCA) is the most recent common ancestor of all current life on Earth, estimated to have lived some 3.5 to 3.8 billion years ago (in the
Paleoarchean The Paleoarchean (), also spelled Palaeoarchaean (formerly known as early Archean), is a Geologic time scale#Terminology, geologic era within the Archean, Archaean Eon. The name derives from Greek "Palaios" ''ancient''. It spans the period of time ...
).


MRCA of different species

The project of a complete description of the phylogenetic relationships among all biological species is dubbed the "
tree of life The tree of life is a fundamental archetype in many of the world's mythology, mythological, religion, religious, and philosophy, philosophical traditions. It is closely related to the concept of the sacred tree.Giovino, Mariana (2007). ''The ...
". This involves inference of ages of divergence for all hypothesized
clades A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of a common ancestor and all its lineage (evolution), lineal descendants – on a phylogenetic tree. ...
; for example, the MRCA of all
Carnivora Carnivora is a monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population Populatio ...
(i.e. the MRCA of "
cat The cat (''Felis catus'') is a Domestication of the cat, domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it ...
s and
dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is Domestication of the dog, derived from the extinct Pleistocene wolf, and the modern wolf is the dog's n ...
s") is estimated to have diverged some 42 million years ago ( Miacidae). The concept of the last common ancestor from the perspective of
human evolution Human evolution is the evolutionary process within the Primate evolution, history of primates that led to the emergence of ''Homo sapiens'' as a distinct species of the hominid family, which includes the great apes. This process involved the grad ...
is described for a popular audience in ''
The Ancestor's Tale ''The Ancestor's Tale: A Pilgrimage to the Dawn of Life'' is a science book by Richard Dawkins and Yan Wong on the subject of evolution, which follows the path of humans backwards through evolutionary history, describing some of humanity's cou ...
'' by
Richard Dawkins Richard Dawkins (born 26 March 1941) is a British evolutionary biology, evolutionary biologist and author. He is an Oxford fellow, emeritus fellow of New College, Oxford and was Simonyi Professor for the Public Understanding of Science, Prof ...
(2004). Dawkins lists "concestors" of the human lineage in order of increasing age, including
hominin The Hominini form a Tribe (biology), taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and ''Pan (genus), Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus '' ...
(human
chimpanzee The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa Although tropical Africa is mostly familiar to the Western world, West for its rainfore ...
), hominine (human
gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or fi ...
),
hominid The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic Family (biology), family of primates that includes eight Neontology#Extant taxa versus extinct taxa, extant species in four Genus, genera: ''Orangutan, ...
(human
orangutan Orangutans are Hominidae, great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in ...
),
hominoid Apes (collectively Hominoidea ) are a clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of a common ancestor and all its lineage (evoluti ...
(human
gibbon Gibbons () are apes in the Family (biology), family Hylobatidae (). The family historically contained one genus, but now is split into four extant genera and 20 species. Gibbons live in subtropical and tropical rainforest from eastern Bangladesh ...
), and so on in 40 stages in total, down to the last universal ancestor (human
bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometre The micrometre (Amer ...
).


MRCA of a population identified by a single genetic marker

It is also possible to consider the ancestry of individual
gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian inheritance#History, Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanin ...
s (or groups of genes,
haplotype A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material (DNA) which is inherited from two parents. Normally these organisms have their DNA o ...
s) instead of an organism as a whole.
Coalescent theory Coalescent theory is a Scientific modelling, model of how alleles sampled from a population may have originated from a most recent common ancestor, common ancestor. In the simplest case, coalescent theory assumes no genetic recombination, recombina ...
describes a stochastic model of how the ancestry of such
genetic marker A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can be ...
s maps to the history of a population. Unlike organisms, a gene is passed down from a generation of organisms to the next generation either as perfect replicas of itself or as slightly mutated ''descendant genes''. While organisms have ancestry graphs and progeny graphs via
sexual reproduction Sexual reproduction is a type of reproduction that involves a complex Biological life cycle, life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to p ...
, a gene has a single chain of ancestors and a tree of descendants. An organism produced by sexual cross-fertilization (
allogamy Allogamy or cross-fertilization is the fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences), also known as generative fertilisation, synga ...
) has at least two ancestors (its immediate parents), but a gene always has one ancestor per generation.


Patrilineal and matrilineal MRCA

Mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DN ...
(mtDNA) is nearly immune to sexual mixing, unlike the
nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryote, eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and Plastid#Structure, plastid ...
whose chromosomes are shuffled and recombined in
Mendelian inheritance Mendelian inheritance (also known as Mendelism) is a type of biology, biological Heredity, inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, an ...
. Mitochondrial DNA, therefore, can be used to trace matrilineal inheritance and to find the
Mitochondrial Eve In human genetics, the Mitochondrial Eve (also ''mt-Eve, mt-MRCA'') is the Matrilineality, matrilineal most recent common ancestor (MRCA) of all world population, living humans. In other words, she is defined as the most recent woman from whom ...
(also known as the ''African Eve''), the most recent common ancestor of all humans via the mitochondrial DNA pathway. Likewise,
Y chromosome The Y chromosome is one of two sex chromosomes ( allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species In biology, a species ...
is present as a single sex chromosome in the male individual and is passed on to male descendants without recombination. It can be used to trace
patrilineal Patrilineality, also known as the male line, the spear side or agnatic kinship, is a common kinship system in which an individual's family membership derives from and is recorded through their father's lineage. It generally involves the inheritanc ...
inheritance and to find the Y-chromosomal Adam, the most recent common ancestor of all humans via the Y-DNA pathway. Approximate dates for Mitochondrial Eve and Y-chromosomal Adam have been established by researchers using
genealogical DNA test A genealogical DNA test is a DNA-based test used in genetic genealogy that looks at specific locations of a person's genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It con ...
s. Mitochondrial Eve is estimated to have lived about 200,000 years ago. A paper published in March 2013 determined that, with 95% confidence and that provided there are no
systematic error Observational error (or measurement error) is the difference between a measurement, measured value of a physical quantity, quantity and its true value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. In statistics, an error ...
s in the study's data, Y-chromosomal Adam lived between 237,000 and 581,000 years ago. The MRCA of humans alive today would, therefore, need to have lived more recently than either. It is more complicated to infer human ancestry via autosomal chromosomes. Although an autosomal chromosome contains genes that are passed down from parents to children via
independent assortment Mendelian inheritance (also known as Mendelism) is a type of biology, biological Heredity, inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, an ...
from only one of the two parents,
genetic recombination Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryot ...
(
chromosomal crossover Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction Sexual reproduction is a type of reproduction that involves a complex Biological life cycle, life cycle in which a gamete (haploid repro ...
) mixes genes from non-sister chromatids from both parents during
meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately ...
, thus changing the genetic composition of the chromosome.


Time to MRCA estimates

Different types of MRCAs are estimated to have lived at different times in the past. These ''time to MRCA'' (''TMRCA'') estimates are also computed differently depending on the type of MRCA being considered. Patrilineal and matrilineal MRCAs (Mitochondrial Eve and Y-chromosomal Adam) are traced by single gene markers, thus their TMRCA are computed based on DNA test results and established mutation rates as practiced in genetic genealogy. The time to the genealogical MRCA (most recent common ancestor by any line of descent) of all living humans cannot be traced genetically because the DNA of the great majority of ancestors is completely lost after a few hundred years. It is therefore computed based on non-genetic, mathematical models and computer simulations. Since Mitochondrial Eve and Y-chromosomal Adam are traced by single genes via a single ancestral parent line, the time to these genetic MRCAs will necessarily be greater than that for the genealogical MRCA. This is because single genes will coalesce more slowly than tracing of conventional human genealogy via both parents. The latter considers only individual humans, without taking into account whether any gene from the computed MRCA actually survives in every single person in the current population.


TMRCA via genetic markers

Mitochondrial DNA can be used to trace the ancestry of a set of populations. In this case, populations are defined by the accumulation of mutations on the mtDNA, and special trees are created for the mutations and the order in which they occurred in each population. The tree is formed through the testing of a large number of individuals all over the world for the presence or lack of a certain set of mutations. Once this is done it is possible to determine how many mutations separate one population from another. The number of mutations, together with estimated mutation rate of the mtDNA in the regions tested, allows scientists to determine the approximate time to MRCA (''TMRCA'') which indicates time passed since the populations last shared the same set of mutations or belonged to the same
haplogroup A haplotype is a group of alleles in an organism that are inherited together from a single parent, and a haplogroup (haploid from the el, ἁπλοῦς, ''haploûs'', "onefold, simple" and en, group) is a group of similar haplotypes that share ...
. In the case of Y-Chromosomal DNA, TMRCA is arrived at in a different way. Y-DNA haplogroups are defined by
single-nucleotide polymorphism In genetics, a single-nucleotide polymorphism (SNP ; plural SNPs ) is a germline substitution of a single nucleotide at a specific position in the genome. Although certain definitions require the substitution to be present in a sufficiently larg ...
in various regions of the Y-DNA. The time to MRCA within a haplogroup is defined by the accumulation of mutations in STR sequences of the Y-Chromosome of that haplogroup only. Y-DNA network analysis of
Y-STR A Y-STR is a short tandem repeat (STR) on the Y chromosome, Y-chromosome. Y-STRs are often used in forensics, paternity, and genealogical DNA testing. Y-STRs are taken specifically from the male Y chromosome. These Y-STRs provide a weaker analysis ...
haplotypes A haplotype (haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Sets of chromosomes re ...
showing a non-star cluster indicates Y-STR variability due to multiple founding individuals. Analysis yielding a star cluster can be regarded as representing a population descended from a single ancestor. In this case the variability of the
Y-STR A Y-STR is a short tandem repeat (STR) on the Y chromosome, Y-chromosome. Y-STRs are often used in forensics, paternity, and genealogical DNA testing. Y-STRs are taken specifically from the male Y chromosome. These Y-STRs provide a weaker analysis ...
sequence, also called the
microsatellite A microsatellite is a tract of repetitive DNA in which certain Sequence motif, DNA motifs (ranging in length from one to six or more base pairs) are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organ ...
variation, can be regarded as a measure of the time passed since the ancestor founded this particular population. The descendants of Genghis Khan or one of his ancestors represents a famous star cluster that can be dated back to the time of Genghis Khan. TMRCA calculations are considered critical evidence when attempting to determine migration dates of various populations as they spread around the world. For example, if a mutation is deemed to have occurred 30,000 years ago, then this mutation should be found amongst all populations that diverged after this date. If archeological evidence indicates cultural spread and formation of regionally isolated populations then this must be reflected in the isolation of subsequent genetic mutations in this region. If genetic divergence and regional divergence coincide it can be concluded that the observed divergence is due to migration as evidenced by the archaeological record. However, if the date of genetic divergence occurs at a different time than the archaeological record, then scientists will have to look at alternate archaeological evidence to explain the genetic divergence. The issue is best illustrated in the debate surrounding the demic diffusion versus
cultural diffusion In cultural anthropology and cultural geography, cultural diffusion, as conceptualized by Leo Frobenius in his 1897/98 publication ''Der westafrikanische Kulturkreis'', is the spread of culture, cultural items—such as ideas, fashion, styles, rel ...
during the
European Neolithic The European Neolithic is the period when Neolithic (New Stone Age) technology was present in Europe, roughly between 7000 BCE (the approximate time of the first farming societies in Greece) and c.2000–1700 BCE (the beginning of the Bronze Age ...
.


TMRCA of all living humans

The age of the MRCA of all living humans is unknown. It is necessarily younger than the age of either the matrilinear or the patrilinear MRCA, both of which have an estimated age of between roughly 100,000 and 200,000 years ago. A study by mathematicians Joseph T. Chang, Douglas Rohde and Steve Olson calculated that the MRCA lived remarkably recently, possibly as recently as 2,000 years ago. The MRCA of all humans almost certainly lived in East Asia, which would have given them key access to extremely isolated populations in Australia and the Americas. Possible locations for the MRCA include places such as the Chuckchi and Kamchatka Peninsulas that are close to Alaska, places such as Indonesia and Malaysia that are close to Australia or a place such as Taiwan or Japan that is more intermediate to Australia and the Americas. European colonization of the Americas and Australia was found by Chang to be too recent to have had a substantial impact on the age of the MRCA. In fact, if the Americas and Australia had never been discovered by Europeans, the MRCA would only be about 2.3% further back in the past than it is. Note that the age of the MRCA of a population does not correspond to a
population bottleneck A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violen ...
, let alone a "first couple". It rather reflects the presence of a single individual with high reproductive success in the past, whose genetic contribution has become pervasive throughout the population over time. It is also incorrect to assume that the MRCA passed all, or indeed any, genetic information to every living person. Through
sexual reproduction Sexual reproduction is a type of reproduction that involves a complex Biological life cycle, life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to p ...
, an ancestor passes half of his or her genes to each descendant in the next generation; in the absence of
pedigree collapse In genealogy, pedigree collapse describes how reproduction between two individuals who share an ancestor causes the number of distinct ancestors in the family tree of their offspring to be smaller than it could otherwise be. Robert C. Gunderson co ...
, after more than 32 generations the contribution of a single ancestor would be on the order of 2−32, a number proportional to less than a single basepair within the
human genome The human genome is a complete set of nucleic acid sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual Mitochondrial DNA, mitochondria. These are usually treated s ...
.


Identical ancestors point

The MRCA is the most recent ''common'' ancestor shared by all individuals in the population under consideration. This MRCA may well have contemporaries who are also ancestral to some but not all of the extant population. The '' identical ancestors point'' is a point in the past more remote than the MRCA at which time there are no longer organisms which are ancestral to some but not all of the modern population. Due to
pedigree collapse In genealogy, pedigree collapse describes how reproduction between two individuals who share an ancestor causes the number of distinct ancestors in the family tree of their offspring to be smaller than it could otherwise be. Robert C. Gunderson co ...
, modern individuals may still exhibit clustering, due to vastly different contributions from each of ancestral population.


See also

*
Cladistics Cladistics (; ) is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically ...
*
Common descent Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...
*
Coalescent theory Coalescent theory is a Scientific modelling, model of how alleles sampled from a population may have originated from a most recent common ancestor, common ancestor. In the simplest case, coalescent theory assumes no genetic recombination, recombina ...
, a retrospective model of population genetics *
Genealogy Genealogy () is the study of families, family history, and the tracing of their Lineage (anthropology), lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family a ...
, the study of families and the tracing of their lineages and history *
Genetic distance Genetic distance is a measure of the genetics, genetic divergence between species or between population#genetics, populations within a species, whether the distance measures time from common ancestor or degree of differentiation. Populations with ...
, the genetic divergence between species or between populations within a species *
Lowest common ancestor In graph theory In mathematics, graph theory is the study of ''graph (discrete mathematics), graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of ''Vertex (graph th ...
, an analogous concept in graph theory and computer science *
Phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree (graph theory), tree showing the evolutionary relationships among va ...
, a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species *
Timeline of evolution The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. Dates in this article are consensus estimates based on scientific evidence, main ...
, outlines the major events in the development of life on the planet Earth * Timeline of human evolution, outlines the major events in the development of the human species *
Last universal common ancestor The last universal common ancestor (LUCA) is the most recent population from which all organisms now living on Earth share common descent—the most recent common ancestor of all current life on Earth. This includes all cellular organisms; ...
, the most recent common ancestor of all life


Notes


References


Further reading

* * {{DEFAULTSORT:Most Recent Common Ancestor Evolutionary biology Genetic genealogy Genealogy Phylogenetics Population genetics Last common ancestors Events in biological evolution