From wolf to Shar-Pei a DNA odyssey
By Eric T. Omura August 20, 2007
(Pictures and chart is missing on this articcle)
Tremendous scientific advancement in the past 50 yearsi particularly in the field of DNAii molecular research, DNA profilingiii, heredity analysis and molecular dating has given us a powerful tool in tracing origin of human and our best friend: dogs. We have tried to understand Shar-Pei by looking into The Tang dog and their relation with Shar-Pei (Simply Shar Pei, winter 2006, issue 40, p. 31). We have attempted to trace the migration routes of dog populations by tracing the migration pattern of prehistoric man from Africa.iv We can further check this hypothesis by doing the reverse: tracing the DNA migration pattern of dogs.
Putting together the latest DNA researches related to dog published in various scientific journals in the past few years, we are now in a much better position to see the origin of Shar-Pei, where did it come from all the way back to the first original primitive dog. A summary of the various DNA researches seen from a Shar-Pei perspective is presented below. Traditional culture and science has finally come together. It is not intended here to explain the technology if one may find difficult to conceive at times, but to present to you a total picture with solid scientific base from original source.
The first dog originated in Asia
In 1997, Swedish scientist, Peter Savolainenv and his team using mitochondrial DNA (mtDNA)vi analytical method arrived at the conclusion that modern day dogs have evolved from the wolvesvii about 135,000 years ago.viii This is much older than the oldest archaeological record discovered today at 14,000 years old determined by C14 carbon dating method.ix Whether the time goes back so far is still open to discussion depending on the dating reference used, but there is high agreement that modern dogs goes back to the wolves.
In 2002, further investigationx has led to the finding that possible origin of domestic dogs originated somewhere in East Asiaxi, and that the mtDNA dating also suggested that a group of primitive dogs goes back to approximately 40,000 years from now. The researchers also found that the other breedsxii they tested were more recent in history of only about 15,000 years old. This implied that these primitive Asian dogs had kept themselves in isolation in East Asia for a long period of time before they spread to the rest of the world.
Therefore, something had happened in human history that triggered this spread of Asian dogs around 15,000 B.P. (before present). If we say this period is the starting point of breed differentiation, then one suggestion is that around 10,000 to 15,000 years ago, the change from nomadic hunter-gatherer societies to more sedentary agricultural population centers may have imposed new selective regimes on dogs that resulted in the marked phenotypic divergence.xiii This period in time when human being began agriculture and domestication of animals is sometimes named by archeologist as the “Neolithic Revolution”.xiv
Then in 2005, a separate group of Italian scientistsxv also confirmed that one of the origins of the dogs is in Asia. However, they challenged that the mtDNA molecular clock may not be accurate as it should be, with tendency to overestimate the recent divergence timesxvi. The Italians set the clock much later, estimated that the genetic separation between dogs and wolves to have occurred only after the Neolithic agropastoral revolution (about 8,000 years ago) when man began to keep livestock, then life between wolves and humans became incompatible.xvii Therefore, using the new time table in interpreting the genetic data, they suggested multiple independent Asian and European domestication events. In either case, the Swedish and the Italian researches both pointed to Asia in the origin of dogs.
Shar-Pei was among the first dog
In 2004, Heidi G. Parker, another independent research teamxviii did a Phylogeneticxix analysis on 414 purebred dogs representing 85 breeds using the microsatellitexx DNA as molecular markers. They were able to show fourteen breeds dated back to antiquity and traced their ancestry to Asia or Africa. The remaining breeds formed a large group of modern dogs presumed to have European origins. Using wolf samplesxxi as the root, they drew up a Phylogenetic tree18 (see figure below) and showed that four Asian spitz-type breeds had the deepest split from the proto-dogs once they diverged from the wolves. Within this first branch, the Shar-Pei split first, followed by the Shiba Inu, and then Chow Chow and Akita together.
(Chart is missing here)
Therefore, Parker’s team concluded that early primitive dogs originated in Asia and migrated with nomadic human groups both south to Africa and north to the Arctic, with subsequent migrations occurring throughout Asia. This Phylogenetic tree configuration confirmed or substantiated a previous research done in 2001 by an independent team of scientists from Korea and Japanxxii. Kim and his team found out that Shiba and Kishu formed the root for all other dogs, including the Korean and the Chinese native dogsxxiii. They suggested two possible routes for gene flow into Eastern Asia in prehistoric time: one from Southeast Asia hip-hopping over the islands, and the second by land over North Asia into the Korean peninsular. Subsequently, the dogs may have hopped over the Aleutians, through Alaska or by sea into North and South America together with human migration.xxiv
In summary, all of the above independent findings from canine DNA analysis are in line with what has been found by Spencer Wells on human DNA migration pattern4. Finally to conclude this article with a few visual impacts: a graphic comparison of traditional Shar-Pei with “Xoloitzcuintli”xxv, Peruvian hairless dog; both original dogs found in South America. The Chinese Crested dogs is here.
Peruvian hairless dog (Reuter Jan. 2007) Xoloitzcuintli25 or Mexican Dog
Hairless and coated varieties.
A rare photo of two traditional bone-mouth Shar-Pei taken in Dali, Guangdong 1995.
Notes and references
i Just over 50 years ago in April 1953, DNA and its molecular structure were discovered by J.D. Watson and F.H.C. Crick at the Cavendish Laboratory, Cambridge, Massachusetts. So the speed of advancement has been truly amazing, probably as amazing as the progress of computers.
ii DNA stands for Deoxyribose Nucleic Acid, the most basic biochemical molecular building block of all living organisms on earth and the fundamental determinant of heredity and genetics.
iii I. Zajc, C.S. Mellersh, E.P. Kelly, J. Sampson, A new method of paternity testing for dogs, based on microsatellite sequences, Vet. Rec. 135, 1994:545-547.
By the end of the 20th century, many gene technologies were already made available to public for practical application. From July, 2000, the American Kennel Club (AKC) began offering DNA testing service to AKC registered dogs born on/after January 1, 2000 for parentage verification and DNA Certification required for frequently used sires.
iv Wells, Spencer, The Journey of Man: A Genetic Odyssey, The Penguin Press, 2002.
Simplified Chinese Translated Edition by Oriental Press, Beijing, China, 2004
By Y chromosome and mitochondrial DNA analysis, it is certain that Chinese today is also descent from Africa and not from the Beijing cave man. (Chinese edition p.98)
v Molecular biologist at the Royal Institute of Technology in Stockholm, Sweden. His team of DNA scientists published in the Science magazine numerous important research papers on evolution and heredity of dogs based on the latest DNA sciences.
vi Mitochondria are an organelle (component) within a cell equivalent to an organ in our body. Because mitochondria are located in the cell body and not in the nucleus, therefore, the DNA of mitochondria is inherited maternally and can be used to trace evolution back along female lines.
vii Bones of wolves have been found in association with those of hominids from as early as 400,000 years ago.
J. Clutton-Brock, the Domestic Dog, Its Evolution, Behavior and Interactions with People, J. Serpell, Ed., Cambridge Univ. Press, Cambridge, 1995: 7-20.
M. E. Thurston, the Lost History of the Canine Race. Our 15,000-Year Love Affair with Dogs, Andrew & McMeel, Kansas City, KS, 1996.
viii Carles Vilà, Peter Savolainen, Jess E. Maldonado, Isabel R. Amorim, Robert K. Wayne et al., Multiple and Ancient Origins of the Domestic Dog, Science, vol.276, June 13, 1997: 1687.
ix G. Nobis, Umshau 19, 610, 1979.
S.J. Olson, Origins of the Domestic Dog, University of Arizona Press, Tucson, AZ, 1985.
Carbon 14 isotope decay dating method is a widely used and reliable method in archaeology today.
It is reliable in dating longer period of not less than unit of 1,000 years.
x Peter Savolainen, Ya-ping Zhang, Jing Luo, Joakim Lundeberg, Thomas Leitner, Genetic Evidence for an East Asian Origin of Domestic Dogs, Science, vol.298, Nov.22, 2002:1613.
xi In the research, the eastern and western parts of the world are defined as the area east and west of a line from the Himalayas to the Ural Mountains.
xii In the investigation, the team used 654 domestic dogs from Europe, Asia, Africa and Arctic America and 38 Eurasian wolves.
xiii D.F. Morey, Am. Sci., 82, 336, 1994.
xv F. Verginelli, C. Capelli, V. Cola, M. Musiani, M. Falchetti, L. Ottini, R. Palmirotta, A. Tagliacozzo, I.G. Mazzorin, R. Mariani-Costantini, Mitochondrial DNA from Prehistoric Canids Highlights Relationships Between Dogs and South-East European Wolves, Mol. Biol. Evol., Vol.22(12), 2005:2541-2551
xvi S.Y.W. Ho, M.J. Phillips, A. Cooper, A.J. Drummond, Time dependency of molecular rate estimates and systematic overestimation of recent divergence times, Mol. Biol. Evol., Vol.22, 2005:1561-1568
xvii M.V. Sablin, G.A. Khlopachev, The earliest ice age dogs: evidence from Eliseevichi 1, Curr. Anthropology., Vol.43, 2002:795-799.
xviii H.G. Parker, L.V. Kim, N.B. Sutter, S. Carlson, T.D. Lorentzen, T.B. Malek, G.S. Johnson, H.B. DeFrance, E.A. Ostrander, L. Kruglyak, Genetic Structure of the Purebred Domestic Dog, Science, Vol. 304, 21 May 2004:1160-1164.
xix Phylogenetic: the study of evolutionary relatedness among various groups of organisms (e.g., species, populations, dogs in our case).
Wikipedia, http://en.wikipedia.org/wiki/Phylogenetic_System, also known as Phylogenetic Systematics, it treats a species as a group of lineage-connected individuals over time.
Dog breeds have traditionally been grouped on the basis of their roles in human activities, physical phenotypes, and historical records. This is a classification based on pattern of genetic variation (Parker et al. 2004).
xx Microsatellites are short repeat DNA units (1-5 base pairs) that are randomly distributed throughout vertebrate genomes. It is a valuable tool in paternity testing, dog mapping, and studies of differentiation among various members of the Canidae family.
I. Zajc and J. Sampson, Utility of Canine Microsatellites in Revealing the Relationships of Pure Bred Dogs, the Journal of Heredity, Vol.90(1), 1999:104.
xxi A diverse set of wolves from eight different countries was included in the analysis. They consisted of eight individuals, one from each of the following countries: China, Oman, Iran, Sweden, Italy, Mexico, Canada, and the United States. (Parker et al. 2004)
xxii K.S. Kim, Y. Tanabe, C.K. Park, J.H. Ha, Genetic Variability in East Asian Dogs Using Microsatellite Loci Analysis, the Journal of Heredity, Vol. 92(5), 2001:398-403.
xxiii All the Asian breeds involved in this research included Sapsaree, Jindo, HAD from Korea; Hokkaido, Akita, Kishu, Shiba from Japan; Shih Tzu from China, and miscellaneous other breeds of Eskimo, Sakhalin, Taiwan for comparison.
xxiv J. A. Leonard, R. K. Wayne, J. Wheeler, R. Valadez, S. Guillen, C. Vila, Ancient DNA Evidence for Old World Origin of New World Dogs, Science, vol. 298, Nov. 2002:1613-1616.
C. Vila, J. E. Maldonado, and R. K. Wayne, Phylogenetic Relationships, Evolution, and Genetic Diversity of the Domestic Dog, The Journal of Heredity 1999:90(1)71-77.