In 1962, two sets of dog remains were excavated at the Kamikuroiwa Rock Shelter site in Ehime Prefecture. 14C age dates of the dog remains correspond to a time period from the end of the Initial Jomon period to the beginning of the Early Jomon period: this indicates that they are the oldest buried dog remains discovered to date in the Japanese archipelago. Both sets of remains represented adult dogs and showed complete permanent dentition. The interred bodies were small, including the bones of their extremities, but they still resembled Jomon dogs of later periods. The muscles had developed, especially those required for mastication, and for the bending and stretching of the extremities. The teeth showed damage due to attrition that most likely occurred prior to death. It has been surmised that the dogs were subjected to extreme levels of stress on their teeth and were buried after tooth loss. Such damage may be related to hunting for large game mammals such as wild boar, similar to Jomon dogs of later periods. Therefore, it is highly possible that these two individuals shared similar characteristics as hunting dogs with Middle, Late, and Final Jomon dogs.
Two complete dog skeletons were recovered during archeological excavations from 1961 to 1970 at the Kamikuroiwa rock shelter, a site that yielded a series of cultural entities from the Late Pleistocene, Incipient Jomon, and Early Jomon periods. Since two dogs were buried close to human skeletons, it was thought that these dogs had been buried by Jomon people, and hence provided the oldest direct evidence of Canis domestication in Japan. However, the stratigraphic information and archeological contexts of these dog skeletons are incomplete due to the lack of detailed excavation reports and technical limitations of excavations at this site. Because the date of the dog burials has not been fully discussed in the context of modern chronology or recent discussions on Canis domestication, we directly measured radiocarbon ages and stable isotope analysis on two dog burials and one set of human remains from the Kamikuroiwa rock shelter. These data are important for reconstructing the relationship between humans and dogs in the Jomon period. Our results show that the human thought to have been buried with the dogs was assigned to the middle Initial Jomon period (8977–8725 calBP), whereas, on the other hand, dates for the dog burials are very close to each other and were assigned to the latest Initial Jomon or the initial Early Jomon periods (7414–7273 calBP). Although these results are not consistent with previous archeological interpretations for this site, they remain important because these two dog burials are among the oldest evidence of Canis domestication in East Asia.
To investigate the genetic variation of Jomon dogs (Canis familiaris) in Japan, partial sequences of the mitochondrial DNA (mtDNA) control region were determined from dog bone remains, which were excavated from two Jomon-period archaeological sites, the Kamikuroiwa Rock Shelter site in Ehime Prefecture (Shikoku Island) and the Higashimyo site in Saga Prefecture (Kyushu Island), Japan. Of seven individuals from the Kamikuroiwa Rock Shelter site, the mtDNA sequences from two individuals were successfully determined. Comparison of the resultant 215 base pair sequences with previously reported sequences showed that one of these two individuals had a new haplotype, named KRA1, and that the other had the previously reported M1 haplotype. For the Higashimyo site, three of 11 individuals yielded successful sequences. Two of these three individuals shared M1 and the other one had M20, both of which are haplotypes previously reported in modern Japanese dogs, but had not been found in any Jomon dogs. The success rate in the present study was 27.8% (5/18 samples). It is noticed that the three mtDNA haplotypes (M1, M20 and KRA1) were found in Jomon dogs for the first time. In addition, sequence data were obtained from Jomon dogs in Shikoku for the first time. The results suggest that the genetic lineages in the Jomon dog populations were more polymorphic than previously reported, and that at least some maternal lineages shared in the Jomon period descended to modern dogs on the Japanese islands.
In 1962, buried dog remains, believed to be the oldest in Japan, were excavated from the Kamikuroiwa Rock Shelter. The remain were lost, however, for nearly a half century until March 2011, when what appeared to be the bones of two Jomon dogs were found at Keio University, where extensive searches had been made over many years. While there were no specific notations on the bones, the name and date of the newspaper in which they were wrapped, remains of other animals packed with the dog bones, features of the limestone debris in the wrappings, and the dating of the dog bones all confirm that these are the missing dog remains from the Kamikuroiwa Rock Shelter. This recovery of the most ancient dog burials in Japan is significant for the study of domestic dogs in this country.
We investigated aging-related changes in the skulls of Japanese macaques (Macaca fuscata). A total of 145 (70 males, 75 females) skulls from macaques aged 7.0–26.9 years (males) and 7.0–30.7 years (females) were measured for 22 craniometric items. Some skull dimensions increased from young adulthood (7.0 years) to the peak at 13.3–19.0 years in males and at 19.7–22.6 years in females. Some dimensions remained at their peak value right through into very old age whereas others continued increasing during this stage of life. Continued increase of cranial size in adulthood has been also observed in humans, but the magnitude of change was greater in macaques. Facial and mandibular dimensions showed larger and more significant increases than neurocranial dimensions in macaques, as in humans, including facial height, bizygomatic breadth, mandibular body height, and ramus breadth in both sexes. Intertemporal distance and biorbital breadths after 16.0 years of age decreased significantly in males, and cranial and posterior basicranial lengths increased only in males. We suggest that these craniometric changes are associated with the development of the insertion area onto which muscles attach (by accumulation of physical stress). The face and mandible are greatly influenced by tooth loss and/or dental disorders, both of which are evident in humans. In the present study large changes were also found in skulls that had lost several teeth.
The present study aims to outline the genetic makeup of the current population of the town of Yanga (Veracruz State, Mexico), the first Latin American settlement founded by African slaves in Mexico. For this purpose, we carried out the genetic characterization of 60 individuals from Yanga, analysing 15 autosomal short tandem repeats (STRs) and interpreting the results in the context of the admixed population known as Mexican mestizos. The genetic contribution from the three most important human groups in the current admixed Yanga population was calculated using Structure software. We detected a high percentage of Amerindian (48%) and European inheritance (44.7%), and a much less important African contribution (7.3%). These results were then compared with 10 other Mexican mestizo populations. The results fit the tri-hybrid model for admixture characterized by a high genetic contribution from Europeans and Africans in the north—though the African influence is lower—and a decreasing contribution from these two populations to the south and southeast. Conversely, the Amerindian component presents maximum values in the south and minimum values in the north. The Amerindian and European genetic traces are related to their ancestral settlements, but the African contribution can be explained by other parameters. To understand the current African genetic traces, we have to assume that there was a redistribution of these population groups and an important admixture phenomenon which led to the dilution of the African ancestral genetic pool. Furthermore, admixture was favoured by conditions that allowed individuals who intermarried to ascend in social status. These reasons would explain why despite the fact that Yanga was founded by black slaves, high levels of African ancestry are not found in the current population.
Dental remains of Homo floresiensis excavated during 2002–2004 at Liang Bua, Flores, Indonesia, consist of one partial maxillary dentition, two nearly complete mandibular dentitions, and four isolated teeth. We present here morphological descriptions of all these specimens and report aspects of their dentition, occlusion, and oral health condition. This dental assemblage represents probably five but possibly four or six individuals. These different individuals share similar dental characteristics, supporting the view that the Liang Bua H. floresiensis assemblage represents a single population. We also reassess the previous claims for primitive and modern aspects of the H. floresiensis teeth. The previous studies reached conflicting conclusions: some researchers claim that these teeth are fully modern, whereas others highlight premolar and other morphologies that suggest their direct evolutionary link with the African earliest form of Homo or Australopithecus rather than with H. erectus. Neither of these views are supported. The H. floresiensis teeth exhibit a mosaic of primitive, derived, and unique characters, with the reported primitive aspects broadly comparable to the morphologies observed in H. erectus sensu lato. Although a more comprehensive comparative analysis is needed to fully illustrate dental morphological affinities of this dwarfed hominin species, we find no grounds for the hypothesis that H. floresiensis originated from the small-bodied, primitive hominins such as H. habilis sensu lato.