EMERGENCEAfrican the recent Genesis of humans Genetic studies reveal that an African woman from less than 200,000 years ago was our common ancestor By Rebecca L. Cann and Allan C. Wilson POINT-COUNTERPOINT: For an opposing view of how humankind arose around the globe, see “The Multiregional Evolution of Humans,” on page 46. 54 SCIENTIFIC AMERICAN Updated from the April 1992 issue COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. But the former evidence has a cru- long as 25 million years ago. The arrows on the map (center) indicate the route and the minimum number of when the paleontologists admitted we unrelated females (red circles) who colonized various areas. when and where populations orig- humans and the great apes occurred as genetic comparisons convince us that all inated. .sciam. LAURIE GRACE African Asian Australian New Guinean Caucasian 180 0 0. A genealogy based on few million years old. this time over the latest phase of place and spread elsewhere. lived about 200. most paleontologists had archaic forebears around the world over of dead ones can explain in isolation claimed the evolutionary split between the past million years. humans today can be traced along ma. 110 100 90 80 70 120 60 130 50 140 40 36 31 150 30 160 20 18 170 Ancestor 15 10 JOE L E MONNIER (map). cial advantage in determining the struc- tained human and ape genes were too ternal lines of descent to a woman who ture of family trees: living genes must have similar for the schism to be more than a AFRICAN ORIGIN for all modern humans is indicated by the genetic evidence. Arguing from their fos.4 0.2 0 Divergence in DNA Divergence in DNA Sequence (percent) Sequence (percent) www. Conversely.2 0. We main. we molecular Once again we are engaged in a de. we won that argument ancestor from Africa.000 years ago.4 0. major debates with the paleon. in Africa.6 0. as inferred from the branching pattern. After 15 years of 182 current mitochondrial DNA types (outer edges) points to the existence of a common female disagreement. Modern humans arose in one geneticists have engaged in two bate.com SCIENTIFIC AMERICAN 55 COPYRIGHT 2003 SCIENTIFIC AMERICAN. I n the quest for the facts about had been right and they had been wrong. our how. human evolution. The paleontologists Neither the genetic information of tologists.6 0. probably human evolution. say modern humans evolved from their living subjects nor the fossilized remains sils. INC. he ed biological information of an individ. whereas dead fossils may not The fossil record. the specialized structures that provide cells with energy. All the mitochondria and the DNA they contain. classified necessarily reflect the models Ramapithecus appeared after the diver- The molecular approach is free from the paleontologists wish to test. other species whose divergences could because they present evidence that has be reliably dated from fossils. ogy. teins. tinguished early hominids from apes. however.ancestors.) To check that mutations had oc- complete because it holds all the inherit. Paleontologists have been passed through lineages that majority of organisms that left no trace had dated its fossils to about 25 million survived to the present. Finally. on the other hand. distance between humans and chim- ly tree it hopes to describe. it was remains represent. M. so specific pecu. knowing the differences reflected found near fossil remains were in fact paleontologist’s perspective therefore mutations that have accumulated since made and used by the population those contains a built-in bias that limits its the species diverged. it supported an upright posture. As such. by any Molecular Clock applied the clock to the chimpanzee-hu- particular evolutionary model. He did liarities need not distort the interpreta. challenged a fossil primate know the genes they are examining must of surviving bones may not represent the called Ramapithecus. Fossils help to fill in compared humans and chimpanzees ual. evolutionary theory must reject the no. Gene se. paleontologists of themselves. actually proceeded. then Sarich measured the evolutionary sils or tools from each part of the fami. ple. when Vincent lion and seven million years ago—far lat- not shaped by theoretical prejudices. say. Studies of mitochondrial DNA can reveal an individual’s maternal ancestry. er than anyone had imagined. The Inheritance of Mitochondrial DNA Egg Fertilized egg 37 genes Mitochondrial DNA Mitochondrion Nuclear DNA MOST OF AN INDIVIDUAL’S GENES are located on DNA molecules in the cell nucleus. also carry some genes for their own manufacture on a ring of DNA. a pelvis as human because that it was directly ancestral to humans. Sarich. rect evidence of how human evolution curred equally fast in both lineages. all the variants on it that the knowledge of how biological pro. INC. genetic sequences that encode the pro- A genome. is tion that the fossils provide the most di. so by calculating the mutation rate in tion of the data. working in Wilson’s labora. ALL THE ADVANTAGES of our field man split. It does not require well-dated fos. much easier to compare proteins for with a set of characteristics that is com. 56 SCIENTIFIC AMERICAN NEW LOOK AT HUMAN EVOLUTION COPYRIGHT 2003 SCIENTIFIC AMERICAN. they believed that blind alley. Sarich now had a molecular clock. individuals who breed only with one an. tory at the University of California at have descendants. Molecular biologists is infamously spotty because a handful Berkeley. but they that all the genetic distances tallied. he not been defined. biologists trained in modern subtle differences than to compare the plete and objective. dating it to between five mil- quences are empirically verifiable and stood revealed in 1967. should not blind us to new lines of evi. against a reference species and found appear within a population— a group of cesses worked in the past. If one gence of the human and ape lineages and several other limitations of paleontol. they contribute equally to the DNA in the nucleus of the resulting Sperm cell. at the outset. in princi. And it concerns itself power of observation. panzees by studying their blood pro- ated by doubts about whether tools Such reasoning tends to circularity. other— can be studied. one is presupposing that bipedalism dis. When a sperm and an egg cell unite. LAURIE GRACE derive from the egg. be interpreted objectively: the phys. classifies. The teins. thickness of the molars and other skele- amine do not lead down an evolutionary ical characteristics by which they are tal characteristics. or full set of genes. (At the time. dence or new interpretations of poorly the next step was to calibrate it. Fossils cannot. Mitochondria. understood and provisionally dated ar. It is not viti. years ago. On the basis of the enamel cannot be sure that the fossils they ex. . Moreover. Genomes are objective chaeological materials. siblings because their mitochondrial duced to arguing that Sarich arrived at For the purpose of scientists studying DNA has had only one generation in the right answer purely by chance. to which creature ancestral to orangutans and not DNA comes in small. back the genealogy goes. cellular organelles that University of Nairobi and at Harvard University. estimated 100. In other words. At first. all human mito- tations that seem to be neither harmful behaves like a fast-ticking clock. nal grandmother.sciam. so all of it today had one female ancestor. evo. and they ac. applied the technique University of California. at the mitochondria. the mitochondrial as it were. every gins. chondrial. the sequences in mitochon. cause maternal lineages die out whenev- methods to the reconstruction of later stages in human evolution only after REBECCA L. long fibers. some severe neurological diseases. which chondrial DNA must have had an ulti- nor beneficial. rings. John A. In this handful of genes. WILSON applied the tools of genetics to paleontology dur- THE AUTHORS 1980. but some mothers trolling skeletal characters do not fall will not produce a daughter. stemmed from the obser. sor of biochemistry at Berkeley. when DNA restriction analysis ing many of their collaborations. The nuclear genes. Those who con. She received both ferences with high resolution. Cann is professor of genetics and molecular biology at the made it possible to explore genetic dif. Every new generation must time divergences from a common stock. we focus on the mito- more recent date for the separation of one is essential: a single adverse muta. the age of some sivapithecine fos.com SCIENTIFIC AMERICAN 57 COPYRIGHT 2003 SCIENTIFIC AMERICAN. tion ends up on the cutting-room floor. descend in to any of the African apes at all. others will produce two or more. til at last it embraces everyone alive. then. the human and ape lines. easy to show she did not necessarily live vation that rates of genetic change from domly from anywhere on the planet are in a small population or constitute the point mutations (changes in individual so alike in most of their DNA sequences only woman of her generation. two-stranded the father does contribute. from the relentless accumulation of mu. But new fossil rest of the cell can use. INC. CANN and ALLAN C. Be- W E C O U L D B E G I N to apply these Second. The de- Two novel concepts emerged from DNA has two advantages over nuclear gree of relatedness declines step by step the early comparisons of proteins from DNA. Any two humans chosen ran. mapithecus is actually Sivapithecus. San Francisco. A native of New Zealand. ing to empirical observations. mo. The father’s contribu- Ramapithecus: it is now clear that Ra. unchanged except for finds undermined the human status of of the nucleus. unlike nuclear DNA. Whereas nuclear DNA encodes an what we may call ordinary lineages. over. Berkeley. mitochondrial which to accumulate mutations. including Wes Brown. accord. changes. Genes con. One was the concept of drial DNA that interest us accumulate first cousins descended from the mater- inconsequential. contain 15 daughters. Mark ifornia.D. many mutations do not alter the mito. . mutations rapidly and steadily. or neutral. the larger the surviving lineages. www. whereas Mitochondrial Clue within this group.Mitochondrial DNA is inherited from the mother alone. Wilson was profes- sampled from around the world. maternal lineages. The farther cumulate at surprisingly steady rates in chondrion’s function. By the early 1980s almost being— mitochondrial DNA encodes For our studies of modern human ori- all paleontologists came to accept Sarich’s only 37. Because scended from a common maternal great- inated by such mutations. mito. most paleontologists clung convert food into a form of energy the chondrial DNA is inherited from the to the much earlier date. which forms bundles of chance mutations. when lineages diverged. million years. grandmother and so on. to second cousins de- Molecular evolution appears to be dom. Israel. Wilson also worked at the Weizmann Institute of Science in Rehovot. Imagine DNA base pairs) were so steady over that we can measure evolution in our a static population that always contains long periods that one could use them to species only by concentrating on the 15 mothers. Cann is using mitochondrial DNA to assay the ge- to trace the maternal lineages of people netic diversity of birds in the Hawaiian Islands. a coated double helix. from different species. in anthropology from the University of Cal- at Berkeley. But it is lecular clocks. he received his doctorate from The DNA we studied resides in the Berkeley. Burns School of Medicine of the University of Hawaii at Manoa. This mitochondrial DNA therefore Logically. however.000 genes— most of the which are of course important to the sils was downgraded to only about six information needed to make a human transmission of physical characteristics. The second concept. she worked at Berkeley with Wilson and at the Stoneking and us. and natural selection does not circle of maternal relatives becomes. as one moves along the pedigree. Unlike the DNA mother alone. More. genes that mutate fastest. mutations. ly neutral. As a postdoctoral fellow. they are effective. is essential for identifying recent genetic mate common female ancestor. tion in any of them is known to cause Maternal lineages are closest among tinue to reject his methods have been re. Until his death in 1991. un- lution at the gene level results mainly eliminate them. Workers her bachelor’s degree in genetics and her Ph. First. each consisting of a protein. people from would trace back to many of the men tant from the chimpanzee sequences. The example found. out of our study is that although geo- over. too. 4 ably correct. 10 tory inherent in elements. New Guineans are typical in this respect. Working at Berkeley with Stoneking. place in the breeding pattern. In fact. all graphic barriers do influence a popula- nary lineages for the population. a great 2 number of different genealogical trees could give rise to any set of genetic data. and The chimpanzee data also illustrated Their genetic diversity had been suspect- Andrew G.” nary lineages. structed had two main branches. tion’s mitochondrial DNA. how remarkably homogeneous humans ed from linguistic analyses of the re- versity. . The name commonly show as much as 10 times the usually classified as Papuan— spoken on “Eve” can therefore be misleading— she genetic variation of humans. that other women panzees. then some of the 14 hu. now at Cornell Uni. the place of origin for modern humans. both of in mind. it. is that all the mitochondrial lineages types were always found among people evolve at the same rate.er there is no daughter to carry it on. Taking the geographic consider. among humans are fairly uniform. al DNA from 241 individuals. On our genealogical tree. panzee sequences than others. In theory. alone suggests that all of modern hu. one maternal that Africa was the ultimate human lineage (dark blue) replaces all the others.000 are at the genetic level: chimpanzees markable variety of language families— people could have lived then. More. Bear analogous sequences from four chim. The as Eve. July 1991]. one must apply the parsi. So when Kocher from the same continent and usually in Eve in Africa conducted his comparison of the human persons who lived within 100 miles of ONE MIGHT REFER to the lucky wo. a given continent do not generally all be- and women who lived at the same time which implies that the rates of change long to the same maternal lineage. however. can. 11 In 1988 Thomas D. as the biblical Eve was. then be explained most easily as the re. If the human lineages had dif. A crucial assumption in this analysis tiple occurrences of mitochondrial DNA lation size. he then concluded maternal lineages proliferate and others become extinct. possible to define the maternal lineages of living individuals all the way back to 1 a common ancestor. Scientific Ameri- From mitochondrial DNA data. In each generation. That fact this one island [see “The Austronesian is not the ultimate source of all the ordi. manity sprang from a relatively small by Peter Bellwood. by chance. estimate that as many as 10. Dispersal and the Origin of Languages. it homeland: the global distribution of mi. which led back to Africa. 3 To recognize the one that is most prob. mitochondrial DNAs. Clark. sup- were living in Eve’s generation and that fered in the rate at which they accumu. now at Harvard University. Hartl. if we were to reconstruct the ordi. which requires that sub- 6 jects be connected in the simplest possi- ble way. In a stable popula. ported the hypothesis that Africa was Eve did not occupy a specially favored lated mutations. Because the tree we con- man whose lineage survives as Eve. is only a matter of time before all but one tochondrial DNA types he saw could we expanded on Kocher’s work by ex- lineage disappears. the time for this fixation of the ma. The mul- generation multiplied by twice the popu. 5 mony principle. INC. some ations into account. 58 SCIENTIFIC AMERICAN NEW LOOK AT HUMAN EVOLUTION COPYRIGHT 2003 SCIENTIFIC AMERICAN. Kocher of Berke- 12 ley (now at the University of New Hamp- shire) applied just such a parsimonious 13 interpretation to the interrelatedness of 14 the mitochondrial DNA of 14 humans 15 from around the world. it is stock of common ancestors. Eventually. he also included one another. they 14 human sequences are nearly equidis. She is man sequences would be significantly One noteworthy point that jumps purely the beneficiary of chance. If the tree holds up. sult of no more than three migration up of 182 distinct types of mitochondri- ternal lineage to occur is the length of a events to other continents. The most efficient hypothetical 7 Generation tree must be tested by comparison with 8 other data to see whether it is consistent 9 with them. it is ana- lyzed for evidence of the geographic his. He determined that 13 branching points were the fewest 16 that could account for the differences he LAURIE GRACE UNIVERSAL MATERNAL ANCESTOR can be found for all the members of any population. shown here traces the lineages of 15 females in a stable population. closer or farther away from the chim. Population geneticists Daniel L. amining a larger genealogical tree made tion. The reaction makes it ferent branches. Con- Thus. . people who are apparently re. New Guinea. and Africans. chondrial DNA was difficult to obtain in sidering the number of African and non- lated by membership in a common geo. we knew it should be possible to calculate LAURIE GRACE INTERRELATEDNESS of 14 humans and four chimpanzees was inferred from similarities discovered in their mitochondrial DNA sequences. ad infinitum.com SCIENTIFIC AMERICAN 59 COPYRIGHT 2003 SCIENTIFIC AMERICAN. Vigilant traced Africa. Fortunately. mutations accumulated both in were constructing our genealogical tree. the African mitochondrial DNAs surveyed.000 Years or Less BECAUSE OUR COMPARISONS with the chimpanzee data showed that the human mitochondrial DNA clock has ticked steadily for millions of years. Satoshi Horai and Kenji Hayasaka of the National Institute of Genetics in Mishima. Similarly. substitutes for Africans. Although these statistical evaluations are not strong or rigorous tests. they would have passed through ter that continent was colonized by a genealogical tree whose 14 deepest Asia. branches would be exclusively African is one in 10. The polymerase chain reaction en- ers whose maternal lineages were most sult of mutations in nuclear genes spread abled Linda Vigilant of Pennsylvania closely related to those in Asia. The non-Afri- the lineages that stayed in Asia and in we had to rely on black Americans as cans lie on shallow secondary branches those that moved on. INC. a small starting sam- Guineans was not someone in New New Guineans were not inherited from ple of DNA can expand into an endless Guinea. Japan. development of a technique called the the probability that the 14 deepest lated in their mitochondrial DNA. stemming from the 15th branch. tochondrially speaking. they. We propose that possible to duplicate DNA sequences common female ancestor of all New the anatomical characteristics uniting easily. ple colonized the island. We estimate the odds of their ar- riving at that conclusion accidentally were only four in 100. analogously surveyed population samples that included many more Asians and individuals from few- er parts of Africa. graphic race need not be very closely re. The population of New Guinea the first settlers. they do make it seem like- African human ly that the theory of an African origin for Non-African person human mitochondrial DNA is now fair- Chimpanzee ly secure. the light skin mitochondrial DNA data from 120 Af- pect if the African origin hypothesis color of many whites is probably a late ricans. by sex and recombination throughout State University to redo our study using That finding is what one would ex. found that the mitochondrial lineages led back to Africa. branches lead exclusively to Africans during the time it took to reach New During the early 1980s. ricans and non-Africans. whose mito.sciam. We assumed that the human and divergences in the human lineages occurred. They evolved after peo. races are not ed that constraint. New Guineans showed up on several dif. Pygmy chimpanzee 200. chiefly as the re.000 for a tree with this branch- ing order. must have been founded by many moth. too. supply. which proved that the like biological species. the sub-Saharan region. Travel was probably slow. chimpanzee lineages diverged five mil- www. The when the common mother of humanity chimpanzee data help researchers to measure when various evolutionary lived. representing six diverse parts of were true: as people walked east out of development that occurred in Europe af. Mi. when we and whose 15th branch leads to both Af- Guinea. the required quantities. Huge levels of gene flow between early continents—very unlikely—would have been needed for multiregionalism. polymerase chain reaction has eliminat. it must also be shown that the cranial people of Europe. Human maternal lineages there. to modern big-brained types. features in question are truly indepen- 60 SCIENTIFIC AMERICAN NEW LOOK AT HUMAN EVOLUTION COPYRIGHT 2003 SCIENTIFIC AMERICAN. Scientific American. especially in the Far million years could still be unreliable for to modern people took place as recently East. All our estimates thus agree that the continents. that shown by the whole human species.” by Christo. a second line of that result. We then calculated how much to measure how much mitochondrial grated from Africa to Asia nearly a mil- humans had diverged from one another DNA has evolved in populations found. in Africa. view. as 130. we ran a test occupied by archaic people who had mi- shown. The remains of least some genes in the modern east remain about how to correct for multi. geneticists such as Masa- PRESENT AFRICAN EUROPEAN EAST ASIAN AUSTRALIAN toshi Nei of Pennsylvania State Univer- sity. gence of Modern Humans. in others. Java Man and Beijing Man are of this from chimpanzees— that is. Anthropol. James Wainscoat of the University of 100.000 years ago. we tion that has since occurred in each of to the multiregional evolution model: determined that the ratio was less than those places seems about one third of similar evolutionary changes in separate 1:25. howev- arose in Africa. have given no hint of ters the environment. people from Eurasia and its mitochon- tion might be interrupted by short bursts pher B. however. Such famous fossils as relative to how much they had diverged ed at a known time.000 Olduvai European Lantian Java the archaic and modern residents of dif- ferent regions.000 ample. LAURIE GRACE ARCHAIC HUMAN GROUPS were gradually replaced throughout the Old World by modern humans who For that argument to hold true. Stringer. and closely to those of their archaic Asian trol region. we arrived at a more ancient date years ago.lion years ago.000 years ago. one biological species. them resemble more modern people led Using two different sets of data. This finding and the hypothesis the ratio of mitochondrial DNA diver. would be neces- chondrial DNA called the control re. we can infer that Eve lived itants from archaic small-brained types as long as five million years. or less than three times 50. ago. they insist that these mor- phologies would be unlikely to evolve Homo erectus independently in any invading people. That date is Those estimates fit with at least one al evolution model also predicts that at less certain. We would expect to find deep clock known to be accurate over five the transition from anatomically archaic lineages in Eurasia. The amount of evolu. Guinea and Australia are estimated to that the archaic Eurasian population un- gence among humans to that between have been founded less than 50. With a third set of data or roughly 150. Kenneth K. Zhoukoudian 300.000 Saldanha Petralona (“Beijing”) Sambungmachan Multiregional Mystery P R O P O N E N T S O F the multiregional evolution model typically emphasize that they have documented a continuity of anatomical morphologies between 700. split happened not far from 200.000 to 60.000 years Huge levels of gene flow between on changes in a section of the mito. east Asia and Australia. and the Americas). It is conceivable. . later in Europe and east Asia. predecessors than to those of modern One might object that a molecular ogists have speculated that in east Africa Africans. for ex. Oceania of change when.000 to derwent anatomical changes that made humans and chimpanzees. The multiregion- for the common mother. Kidd of Yale Universi- ty.000 Klasies Neandertal Ngandong Oxford and Luigi L. The fossil record shows clearly any truly ancient lineages survive unde- To rule out the possibility that the clock that the southern parts of Eurasia were tected in Eurasia. or intense natural se. 200. a new mutagen en. Moreover. Yet surveys in our laboratories and shorter periods. Archaic females do not seem to have contributed mitochondrial genes to the modern er. or a virus infects On the other hand. lion years ago. evidence appears to conflict with this It therefore seems very unlikely that lection affects all segments of the DNA. drial DNA satellites (Australia. we found The aboriginal populations of New type. however. December 1990]. Cavalli-Sforza of Dali Stanford University have found support for an African origin model in their stud- Age (years) ies of nuclear genes.000 sary to maintain human populations as gion.000 to 180. the germ-line cells. anatomically modern people appear first Asian population would be linked more ple mutations that occur within the con. that intervals of genetic stagna. then in the Middle East. as Sarich’s work had might run by fits and starts.000 years. geographic regions converted the inhab- fore grew apart in a period less than 1⁄ 25 Accordingly. We simply do not see the result predicted by the regional mod- el. say. involving more than 1. 60. INC.000 years ago [see “The Emer. because questions line of fossil evidence. Wilson in Proceedings of the quences on the Y chromosome that de. S. base changes ac. pages 31–36. Preliminary molecular studies have earliest migration out of Africa is closer off from breeding with other hominids. pages 9350–9354. Serjeantson. Neverthe. INC. inherited from the father alone. 6099. No. genome sequencing— all 16. while at the College of France. that natur- Son al selection would not tend to favor cer- tain constellations of functionally relat.000 years ago than 200. specific genetic sequences to the physical and behavioral traits that those se. MORE TO E XPLORE quences ultimately influence. With them. such as advanced by our friendly rivals. Particularly enticing are the se- LAURIE GRACE Renee Pennington. dent of one another— that is. may be able to provide an invaluable S I N C E T H I S A R T I C L E was first pub- How one human population might check on our results for maternal lin. Yet we know that powerful jaw muscles may impose changes on the mandible. His mitochondrial lineage (blue line) leads back to only one person in every generation. 1991. . Edited by Adrian V. tween ancient and modern Homo sapi- have contributed to the process by help. some fossil finds do support the trace paternal lineages to a single pro. 23. tochondrial DNA sequences of three any detectable genetic mixing is still a cumulate slowly on useful regions of the Neandertal specimens upholds our con- compelling mystery. Honjo. already been conducted on DNA from to 120. Father Mother ed features anyway. C. Gerard Wilson in Evolution of Life. Cavalli. yet they left little evidence finements this work on paternal lineages Epilogue of interbreeding. They argue that modern populations are not linked to past ones by morphological charac- teristics that evolved uniquely in the fos. making it technically clusions about the lack of a mixture be- suspects that infectious diseases could difficult to conduct a detailed genealog. National Academy of Sciences USA. The continuity seen by believ. circum- stances that promoted the evolution of these features in one population might do so again in a related population.569 base Sforza has speculated that the ancestors as molecular biologists learn to apply pairs from more than 50 donors— gives of modern humans may have developed their techniques to materials uncovered more precise resolution to the timescale some modern trait. trees. from still older fossilized bone now ap- mixture may sound unlikely. range we had originally estimated. both nuclear and mitochondrial DNA Mitochondrial DNA. T.” if you will. proved methods of extracting DNA replace them completely without any and his colleagues have indirectly com. termine maleness and that are therefore Sequence Evolution of Mitochondrial DNA in Humans and Chimpanzees. Oxford University Press. Furthermore. whole mitochondrial ing to eliminate one group. nuclear DNA. The idea that modern humans could cohabit a region with archaic ones and Lucotte. No. Male sil record. Thomas D. 325. Vol. Mitochondrial DNA source teristics. of our emergence. Osawa and T. Tokyo.sciam. further studies of Nature. Hill and Susan W. Springer-Verlag. we may less. Instead fossils and modern Female populations are united by their shared retention of still older ancestral charac. Wilson in The Colonization of the Pacific: A Genetic Trail.com SCIENTIFIC AMERICAN 61 COPYRIGHT 2003 SCIENTIFIC AMERICAN. 1989. Kocher and Allan C. Cann.000 years This and related questions may yield as mummified tissues found in a Florida ago— more recent. Rebecca L. One of us (Cann) Y chromosome. ens. 1987. Those that was alive when the human family in Israel suggest that Neandertals and preliminary results also point to an was young. December 1989. yet still within the molecular biologists learn how to link bog and dated to 7. and with further re- 40. PEDIGREE of one individual illustrates the difference between the patterns of nuclear and ers in multiregional evolution may be an mitochondrial inheritance. Other paleontologists also dispute the evidence for continuity. All 32 ancestors from five generations ago contributed equally to his illusion. further genetic work on the mi- have replaced archaic humans without eages. January 1–7. Edited by S. Stoneking and A. ical analysis. It now seems that the language skills. lished. C. Mark Stoneking and Allan C. D. begin building the family tree from a root idea. Linda Vigilant.500 years ago.000 years. Wilson in Even before then. the browridge and other points on the skull. Discoveries in the caves at Qafzeh genitor —“Adam. will render more informative genetic Mitochondrial DNA Sequences in Single Hairs from a Southern African Population. modern humans lived side by side for African homeland. www. Im. Vol. Mitochondrial DNA and Human Evolution. 86. pared such sequences in an effort to pear close at hand. Unfortunately. M. that effectively cut them gists. Kocher and A. More progress can be expected soon. the paleontolo. Henry Harpending.
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