Advertisement

Asian Archaeology

, Volume 1, Issue 1–2, pp 111–121 | Cite as

Bioarchaeological analysis of Bronze Age populations in the Xiaohe cemetery using dental non-metric traits

  • Zhu Hong 
  • Xu ZhangEmail author
  • Li Wenying 
  • Abuduresule Yidilisi
Original Paper
  • 181 Downloads

Abstract

The archaeological site of the Xiaohe cemetery (3980 to 3540 years cal BP), one of the earliest sites in the Lop Nur Desert of Xinjiang, China, has attracted considerable attention in recent years due to its well-preserved organic materials such as mummified human remains. However, questions of the regional diversity of populations from this time period are still not well understood, as few detailed studies have been undertaken. This study utilizes 17 dental morphological traits to assess the phenetic relationships between Xiaohe (19 males and 17 females) and other ancient populations from northern China and Eurasia. Trait frequencies are determined and biodistances are calculated through Mean Measure of Divergence (MMD) statistics. Based on our MMD results, we suggest that there had already been a certain degree of genetic exchange between people of the Xiaohe area and other parts of Eurasia before the early Bronze Age. These results are consistent with other genetic studies on the Xiaohe cemetery.

Keywords

Xiaohe cemetery Bronze Age Xinjiang Dental non-metric traits 

1 Introduction

The Xinjiang Uygur Autonomous Region (also called Xinjiang 新疆 for short), located in the northwest region of China, has been identified as an important bridge connecting Eastern and Western populations and cultures from across the Eurasian continents. For example, it is well known that the ancient Silk Road connected Central Asia, Eastern Europe, and China. Human activities in Xinjiang can be traced almost as far back as 10,000 years ago (Wang 1992), and archaeological excavations in Xinjiang have been carried out since the late nineteenth century (Xiao 2004).

The Xiaohe 小河 (literally, “Small River”) cemetery (40°20′11″N, 88°40′20.3″E), located in the northeastern part of Xinjiang, is one of the earliest Bronze Age sites in the region, radiocarbon dated to 3980–3540 cal BP (Li 2010). An aboriginal hunter named Ördek first found the site around 1910. Formal excavations began in 1934, when Folke Bergman, a Swedish archaeologist, excavated 12 burials, revealing “European-looking” mummies with brown hair and fine aquiline noses (Bergman 1939). After that, the Xiaohe cemetery was forgotten until the end of 2000, when a Chinese film crew entered the cemetery with the help of a Global Position System (GPS), and their rediscovery aroused widespread attention. To prevent the Xiaohe cemetery from being destroyed, a joint team from the Institute of Cultural Relics and Archaeology of Xinjiang and the Research Center for Chinese Frontier Archaeology of Jilin University excavated this cemetery from 2002 to 2005, but unfortunately, many of the burials had already been destroyed by treasure hunters (Yidilisi et al. 2007).

The Xiaohe cemetery was divided into southern and northern parts by a palisade, and excavation revealed a 5-layer stratigraphy. A total of 167 graves were excavated with remains of 107 human individuals identified. Mitochondrial DNA and Y chromosomal DNA analyses completed on these individuals suggest that the ancient Xiaohe people were admixtures of people originating from both eastern and western Eurasia, especially from southern or eastern Siberia and eastern Europe. This confirmed Bergman’s observation that this region had been populated by groups of people with mixed European lineage some 4000 years ago (Li 2010; Li et al. 2010).

In recent years, comparative studies of populations using dental non-metric traits, characterized by the degree of expression or presence rather than their size, have gained momentum. Because the non-metric traits used are thought to be selectively neutral and because they have a high degree of heritability, they can serve as markers of phylogenetic relatedness. Such studies can be very useful for understanding genetic history, and they provide access to genetic relationships even if ancient DNA research fails, as different parts and amounts of the genome are assessed. Biological anthropologists thus use these studies to estimate the genetic similarity of past human populations.

Observations from people across the world show regional differences in trait pervasiveness and some traits that are unique to populations in specific geographic regions Scott and Turner 1997. Based on the extensive research and compilations of data from many other researchers, Scott and Turner (1997) list and discuss the global frequency of many crown and root traits and find that there is sufficient evidence to demonstrate differences in the occurrence and frequency of many dental non-metric traits between Western European and Central Asian populations. They note that one of the most interesting fields of dental non-metric trait research is on peoples who lived in areas of overlap between Asian and European population ranges. In particular, groups from Southern Siberia are of interest for their geographic intermediacy and because this region witnessed major migrations from a number of different populations and regions over the last 40,000 years, during which population admixture would be expected (Scott and Turner 1997).

In our study, the dental non-metric traits of individuals from the Xiaohe cemetery are used in comparison with other Eurasian inhabitants in order to analyze their biological distances. Given the assumptions that the phenetic similarity provides an acceptable estimate of genetic relationship (Scott et al. 1983) and the samples we observe are representative of the once living population, our results are used to interpret the peopling of Lop Nur Desert in order to assess the hypotheses of biological continuity or discontinuity through time in Xinjiang.

2 Materials and methods

The analyzed sample from the Xiaohe cemetery consists of 36 adult individuals (19 males and 17 females) with a total of 276 teeth. The individuals were mostly selected from cultural layers nos. 4 and 5 in both the northern and southern parts of Xiaohe cemetery (Table 1). Sex estimation of all skeletons followed osteological techniques summarized in Shao’s Manual (Shao 1985) and Standards (Buikstra et al. 1994).
Table 1

Basic information on the Xiaohe samples used in this study

No.

Cemetery part

Layer

Sex

Age

1

04XHM39

Southern

No. 3

Adult

2

04XHM62

Southern

No. 3

Adult

3

04XHM63

Southern

No. 3

♂?

30±

4

04XHBM5

Northern

No. 4

25±

5

04XHBM8

Northern

No. 4

20–25

6

04XHBM10

Northern

No. 4

35±

7

04XHBM20

Northern

No. 4

25–30

8

04XHM70

Southern

No. 4

30–40

9

04XHM87

Southern

No. 4

45–50

10

04XHM88

Southern

No. 4

Adult

11

04XHM96

Southern

No. 4?

Adult

12

04XHM99

Southern

No. 4

30–35

13

04XHM129

Southern

No. 4

45–50

14

04XHM130

Southern

No. 4

25–30

15

04XHM85

Southern

No. 5

Adult

16

04XHM93

Southern

No. 5

35–40

17

04XHM102

Southern

No. 5

25–30

18

04XHM106

Southern

No. 5

35±

19

04XHM107

Southern

No. 5

40–45

20

04XHM109

Southern

No. 5

50±

21

04XHM110

Southern

No. 5

19–20

22

04XHM111

Southern

No. 5

25–30

23

04XHM112

Southern

No. 5

25–30

24

04XHM115

Southern

No. 5

35–40

25

04XHM117

Southern

No. 5

40±

26

04XHM120

Southern

No. 5

45±

27

04XHM121

Southern

No. 5

Adult

28

04XHM125

Southern

No. 5

Adult

29

04XHM128

Southern

No. 5

40

30

04XHM131

Southern

No. 5

30–35

31

04XHM132

Southern

No. 5

40±

32

04XHM134

Southern

No. 5

14–15

33

04XHM135

Southern

No. 5

40±

34

04XHM136

Southern

No. 5

35±

35

04XHM138

Southern

No. 5

35±

36

04XHM139

Southern

No.5

40–45

Evaluation of dental non-metric traits varies from recording the presence or absence of a trait (e.g., Premolar Odontomes), counting the number of structures (e.g., root number), to scoring the expression of a trait on a graded scale (e.g., shoveling). For many traits, it is necessary to establish a range of presence (breakpoint) whereby the trait is considered present or absent, known as trait dichotomization, in order to include it in standard non-metric statistical tests. Our study uses the trait dichotomizations developed by Turner and scored based on the Arizona State University Dental Anthropology System (Turner et al. 1991).

Because dental wear greatly reduces the number of traits that can be observed in an individual, in many cases less than one-third of the full suite of dental non-metric traits could be scored. And because ante-mortem or post-mortem tooth loss also contributes to the loss of information, it was possible to observe a maximum of 17 traits in an individual (Table 2). Some of these traits are suggested to be the most efficient to distinguish differences between Eurasian populations (Scott and Turner 1997). For example, Europeans show simple crown morphology, they are characterized by moderate frequencies of incisor shoveling with few pronounced shovel forms, a high frequency of Carabelli’s cusp, and low frequencies of cusp 6, cusp 7, and deflecting wrinkle, while Mongolian populations are characterized by high frequencies of incisor shoveling, central incisor double-shoveling, one-rooted upper first premolar, deflecting wrinkle, and 3-rooted lower first molar.
Table 2

Dental non-metric traits used in our study

No.

Traits

Abbreviation

Teeth

Grades

Range of presence

1.

Winging

WING

UI1

1–4

1–2

2.

Shoveling

SHOV

UI1

0–7

3–7

3.

Double-Shoveling

DSHOV

UI1

0–6

2–6

4.

Tuberculum Dental

TD

UI2

0–6

1–6

5.

Double-Rooted Upper Premolars

2RT UP1

UP1

1–3

2

6.

Cusp 5

CUSP5

UM1

0–5

1–5

7.

Carabelli’s Trait

CARA

UM1

0–7

2–7

8.

Three-Rooted Upper Molars

3RT UM2

UM2

1–4

3

9.

Double-Rooted Lower Canines

2R LC

LC

1–2

2

10.

Multiple Lingual Cusps

MLC LP2

LP2

0–9

2–9

11.

Cusp 6

C6 LM1

LM1

0–5

1–5

12.

Cusp 7

C7 LM1

LM1

0–5

1–5

13.

Defecting Wrinkle

DW

LM1

0–3

2–3

14.

Three-Rooted Lower Molars

3R LM1

LM1

1–3

3

15.

Four-Cusped Lower Molars

4C LM2

LM2

4–6

4

16.

One-Rooted Lower Molars

1R LM2

LM2

1–2

1

17.

Premolar Odontomes

ODONT

U/LP

0–1

1

Basically, while both maxilla and mandible are scored for the trait, the trait is only counted once. In cases where there is symmetry in trait expression, the antimere with the maximum value is used, based on the assumptions that the trait with the higher expression represents the individual’s maximum genetic potential, and that it occurs randomly with respect to the side of the jaw on which it occurs (Scott and Turner 1997).

Dental Non-metric trait data from previous studies on ancient people of northern China, where the same methodology was used, are used as comparison groups (Fig. 1, Table 3).
Fig. 1

Geographic locations of the Chinese sample data sets used in this study

Table 3

The comparative samples from China used in this study

Sample

Sizea

Time period

Location

Reference

Liushui 流水

108

Bronze Age

Xinjiang

Zhang et al. 2014

Yanghai 洋海

35

Early Iron Age

Xinjiang

Lee 2007

Jilintai 吉林台

78

Iron Age

Xinjiang

Zhang 2010

Yingpan 营盘

23

Iron Age

Xinjiang

Zhang and Zhu 2013

Miaozigou 庙子沟

28

Neolithic

Inner Mongolia

Liu and Zhu 1995

Xiawanggang 下王岗

187

Neolithic

Henan

Liu 1995

Jiangjialiang 姜家梁

62

Neolithic

Hebei

Li 2004

Mogou 磨沟

115

Bronze Age

Gansu

Zhao 2013

Taojiazhai 陶家寨

68

Iron Age

Qinghai

Zhang 2008

Longxian 陇县

97

Iron Age

Shanxi

Liu and Zeng 1996

aBecause sample size varies per non-metric trait within a single sample, the means of these sizes are presented here

In addition, the data collected from 11 Eurasian populations by Scott and Turner (1997) were also used. These samples include (1) Western Eurasia, identified in Western European, Northern European, and Northern African groups, characterized by retained traits and a less complex dentition, (2) Sino-American, characteristic of China- Mongolian, Jomon, recent Japan, northeast Siberia, south Siberia, American Arctic, northwest north American Indians, and north and south American Indians. Geographic locations for all these samples are shown in Fig. 2 and the different frequencies of the non-metric traits in tooth crown and root of the Western Eurasia and Sino-Americas are listed in Table 4.
Fig. 2

Map of the locations of the Eurasian populations’ dental samples (modified from Scott and Turner 1997)

Table 4

Frequencies of the non-metric traits in tooth crown and root of the Western Eurasian and Sino-American groups

Trait

Frequency

Trait

Frequency

WING

0–15%:

Western Eurasian groups

C7 LM1

0–10%:

Western Eurasian groups, Sino-American groups

15–30%:

China-Mongolia, American Arctic

SHOV

0–15%:

Western Eurasian groups

DW

5–15%:

Western Eurasian groups

20–50%:

South Siberia, Jomon

20–35%:

China-Mongolia

60–90%:

China-Mongolia, American Arctic, Northwest North American Indians, North and South American Indians

35–55%:

American Arctic, Northwest North American Indians, North and South American Indians

D SHOV

0–15%:

20–40%:

55–70%:

Western Eurasian groups

China-Mongolia, American Arctic

Northwest North American Indians, North and South American Indians

4C LM2

10–30%:

30–60%:

>80%:

American Arctic, Northwest North American Indians, North and South American Indians

China-Mongolia

Western Eurasian groups

2RT UP1

5–15%:

American Arctic, Northwest North American Indians, North and South American Indians

3R LM1

0–5%:

Western Eurasian groups, Jomon, South Siberia

20–30%:

China-Mongolia, Jomon

5–15%:

Northwest North American Indians, North and South American Indians

30–60%:

Western Eurasian groups

>20%:

China-Mongolia, American Arctic

CUSP5

10–25%:

Western Eurasian groups, Sino- American groups

1R LM2

0–10%:

10–20%:

20–30%:

Jomon

Northern Africa

Western Europe, Northern Europe

CARA

0–10%:

10–15%:

>20%:

American Arctic, Northwest North American Indians, North and South American Indians, Jomon

China-Mongolia

Western Eurasian groups

>30%:

China-Mongolia, South Siberia, Northwest North American Indians, North and South American Indians

C6 LM1

0–10%:

Western Eurasian groups

ODONT

0–1%:

Western Eurasian groups, Jomon, South Siberia

10–20%:

South Siberia

1–3%:

Northeast Siberia

30–50%:

China-Mongolia, American Arctic, Northwest North American Indians, North and South American Indians

4–7%:

China-Mongolia, American Arctic, Northwest North American Indians, North and South American Indians

All the non-metric traits used in this study was chosen based on the congruity of traits between the data sets used.

Firstly, we exclude from analysis individuals whose traits are unobservable due to damage or wear, and then we calculate trait frequencies according to the number of observable individuals but not the number of teeth. That is, a trait was scored as present whether it was present on either the left or the right side. Also, we compare trait frequencies between sexes in the Xiaohe cemetery by using Fisher’s exact test with significance determined at P < 0.01.

The Smith’s Mean Measure of Divergence (MMD) is used as a statistical test of biological distance in order to study the phenetic distances between Xiaohe and the other populations. The MMD calculates dissimilarity for each trait frequency between two populations, and takes the mean of these measures to produce a distance value. The closer the value is to 0, the more closely related the two populations are. Likewise, the larger the value, the more phenetic distance the two populations share. This study calculates data from Xiaohe with the various comparative groups using the following formulas:
$$ \theta =\frac{1}{2}{\mathit{\sin}}^{-1}\left(1-\frac{2m}{n+1}\right)+\frac{1}{2}{\mathit{\sin}}^{-1}\left(1-2\left(\frac{m+1}{n+1}\right)\right) $$
(1)
Where m is the number of specimens with the expressed trait, and n is the total number of specimens observed for that trait. The resulting θ is used in the MMD formula.
$$ MMD=\frac{\sum_{k=1}^r\left({\left({\theta}_{ik}-{\theta}_{jk}\right)}^2-\left(\frac{1}{n_{ik}+\frac{1}{2}}+\frac{1}{n_{jk}+\frac{1}{2}}\right)\right)}{r} $$
(2)

Where θik and θjk are the arcsine-transformed frequencies of samples i and j for trait k, nik and njk are the number of observed specimens for sample i and j for trait k, respectively, and r is the number of traits used.

The MMD result is statistically significant if it is larger than twice the standard deviation (Green and Suchey 1976; Harris and Sjøvold 2004). The two populations being compared were considered statistically significantly different (P < 0.05) when the MMD was greater than twice its standard deviation (Harris and Sjøvold 2004; Irish 2010). The standard deviation was calculated by obtaining the square root of the variance of the MMD, calculated as:
$$ {\mathrm{Var}}_{\mathrm{MMD}}=\frac{2}{{\mathrm{r}}^2}\sum \limits_{\mathrm{k}=1}^{\mathrm{r}}{\left(\frac{1}{{\mathrm{n}}_{\mathrm{ik}}+\frac{1}{2}}+\frac{1}{{\mathrm{n}}_{\mathrm{jk}}+\frac{1}{2}}\right)}^2 $$
(3)
$$ {\mathrm{SD}}_{\mathrm{MMD}}=\sqrt{{\mathrm{Var}}_{\mathrm{MMD}}} $$
(4)

Where nik and njk are the number of observed specimens for sample i and j for trait k, respectively, and r is the number of traits used.

If the resulting calculations indicate a statistically insignificant MMD value, or a negative MMD value, then the value should be set at 0, meaning that no divergence exists between the two groups. This again follows the recommendations of previous research, given that negative MMD distances “have no biological meaning” (Harris and Sjøvold 2004), and should be set as such (Harris and Sjøvold 2004; Irish 2010).

3 Results

There were no significantly different trait frequencies at P < 0.01 between males and females in dental non-metric traits in the Xiaohe cemetery (Table 5), so we have pooled the two sexes for our analyses.
Table 5

P-values from Fisher’s exact test of the differences in number of individuals at or above the presence threshold for each trait between sexes of the Xiaohe cemetery

No.

Traits

P-values

1.

WING

1

2.

SHOV

1

3.

DSHOV

0.471

4.

TD

1

5.

2RT UP1

1

6.

CUSP5

1

7.

CARA

1

8.

3RT UM2

1

9.

2R LC

1

10.

MLC LP2

1

11.

C6 LM1

1

12.

C7 LM1

13.

DW

14.

3R LM1

15.

4C LM2

1

16.

1R LM2

1

17.

ODONT

1

Among non-metric traits listed in Table 6, for maxillary teeth, 31.03% (9/29) of the observable Xiaohe individuals had Winging on the central incisor(s), almost the same frequency as in China-Mongolia and American Arctic (15–30% of individuals), and higher than in the three Western Eurasian groups (0–15%). 33.33% (5/15) of the Xiaohe individuals had Shoveling (Fig. 3a), in which the lowest frequencies are in Western Eurasian groups (0–15%), then South Siberia and Jomon (20–50%), and highest in Native Americans and China-Mongolia. Only one of sixteen (6.25%) Xiaohe individuals had double-shoveling on the central incisor(s) in which the lowest frequencies are in three Western Eurasian groups (0–15%), then China-Mongolia and American Arctic (20–40%), and highest in Native Americans (55–70%). Almost two thirds (63.64%, 7/11) of the individuals from Xiaohe had the tuberculum on the lateral incisor(s). 4% (1/25) of the individuals from Xiaohe had odontomes on upper premolars. 55.56% (20/36) of the individuals at Xiaohe had two roots on the first premolar (Fig. 3b), which is more like the frequencies in the three Western Eurasian groups (30–60%). Three (30%, K = 10) of the Xiaohe people had five crowns, while two (22.22%, K = 9) had Carabelli’s trait on the first molar, the same as in the three Western Eurasian groups (>20%), then China-Mongolia, and rarest in Native Americans and Jomon (0–10%). 71.43% (20/28) of the Xiaohe people had three roots on the second molar (Fig. 3c).
Table 6

Frequencies of dental non-metric traits of the Xiaohe cemetery

Traits

Range of presence

Times seen (N)

Number of samples (K)

Frequency

Maxillary

 WING

1–2

9

29

31.03

 SHOV

3–7

5

15

33.33

 DSHOV

2–6

1

16

6.25

 TD

1–6

7

11

63.64

 ODONT

1

1

25

4.00

 2RT UP1

2

20

36

55.56

 CUSP5

1–5

3

10

30.00

 CARA

2–7

2

9

22.22

 3RT UM2

3

20

28

71.43

Mandible

 2R LC

2

1

32

3.13

 ODONT

1

1

25

4.00

 MLCLP2

2–9

1

14

7.14

 C6 LM1

1–5

2

12

16.67

 C7 LM1

1–5

0

11

0

 DW

2–3

0

11

0

 3R LM1

3

0

34

0

 4C LM2

4

7

9

77.78

 1R LM2

1

4

31

12.90

Fig. 3

Typical specimens of the dental non-metric traits from the Xiaohe cemetery. a Shoveling: 04XHM130; b Double-Rooted Upper Premolars: 04XHM112; c Three-Rooted Upper Molars: 04XHBM20

For mandible teeth, none (0 of K = 11) had a Cusp 7 and defecting wrinkle, the same frequency as three roots on the first molars (0 of K = 34). One (3.13% of K = 32) of the individuals at Xiaohe in whom the trait could be observed had 2 Roots on lower canines, and one (4% of K = 25) had odontomes on lower premolars and one (7.14% of K = 14) had multiple lingual cusps on second premolars. All the above frequencies are more like in the three Western Eurasian groups. While two (16.67% of K = 12) had a cusp 6 like people in South Siberia (10–20%), and four (12.9% of K = 31) had one-rooted lower molars like the population in Northern Africa (10–20%). Seven out of nine (77.78%) individuals had 4 cusps on second molars, more like in the three Western Eurasian groups (>80%).

Xiaohe people, like most Western European populations, have higher frequencies of traits such as Carabelli’s trait absence, and 2-rooted upper first premolars, while like typical China-Mongolian people, have Moderate frequencies of shoveling, and higher frequencies of upper central incisor winging.

Based on frequency data and MMD results between Xiaohe and the other compared groups (Tables 7 and 8), all of the MMD scores are larger than twice the standard deviation, showing that all the resulting distances are statistically significant.
Table 7

Frequencies of 10 non-metric traits of the tooth crown and root in the Xiaohe and other Northern Chinese populations

Traits (teeth)

Range of presence

XHa

LS

JLT

YP

YH

MZG

XWG

JJL

MG

TJZ

LX

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

TD

1–6

11

63.6

36

100

31

12.9

8

12.5

8

0

20

45.0

78

35.9

49

55.2

72

37.5

12

0

31

22.5

CUSP5

1–5

10

30.0

42

33.3

69

7.2

23

4.3

32

0

18

16.7

125

4.0

52

3.8

111

6.3

53

5.7

55

3.6

CARA

2–7

9

22.2

39

30.8

53

22.6

21

28.6

31

16.1

17

11.8

128

0

56

7.2

107

15.0

56

17.9

54

5.6

3RT UM2

3

28

71.4

89

69.7

70

75.7

22

72.7

27

70.4

18

88.9

115

77.4

59

64.4

91

54.9

58

58.6

56

71.4

MLC LP2

2–9

14

7.1

64

40.6

62

50.0

16

62.5

19

57.9

23

87.0

135

77.8

59

67.8

99

76.8

41

61

48

75

C6 LM1

1–5

12

16.7

60

43.3

76

6.6

18

0

32

0

16

31.3

162

14.8

59

50.1

102

22.5

56

7.1

65

46.2

C7 LM1

1–5

11

0.0

59

5.1

75

5.3

19

15.8

34

5.9

17

11.8

155

2.6

57

15.8

103

8.7

60

0

60

1.7

3R LM1

3

34

0.0

103

1.0

78

0

23

0

29

0

21

47.6

187

36.4

61

11.5

103

15.5

66

21.2

76

26.3

4C LM2

4

9

77.8

59

45.8

76

88.2

22

86.4

32

81.3

16

18.8

156

27.6

59

22.4

73

43.8

54

42.6

54

18.5

1R LM2

1

31

12.9

99

23.2

74

20.3

23

8.7

28

0

18

27.8

184

31.0

66

21.2

73

34.2

60

30

70

34.3

MMD

0.262

0.221

0.361

0.649

0.735

0.676

0.495

0.435

0.625

0.660

SDMMD b

0.045

0.044

0.062

0.057

0.060

0.040

0.044

0.041

0.048

0.045

2*SDMMD

0.089

0.087

0.124

0.114

0.121

0.079

0.088

0.082

0.096

0.089

aXH-Xiaohe, LS-Liushui, JLT-Jilintai, YP-Yingpan, YH-Yanghai, MZG-Miaozigou, XWG-Xiawanggang, JJL-Jiangjialiang, MG-Mogou, TJZ-Taojiazhai, LX-Longxian

bSDMMD -Standard deviation

Table 8

Frequencies of 15 non-metric traits of the tooth crown and root in the Western Eurasia and Sino-American populations

Traits (teeth)

Range of presence

XHa

WE

NE

NA

CM

JO

RJ

NES

SS

AA

NWA

NSAI

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

N

%

WING

1–2

29

31.0

180

7.2

150

5

460

7.5

591

24.5

166

19.9

265

21.9

112

33.9

109

18.3

220

23.2

226

35.8

1177

50

SHOV

3–7

15

33.3

186

2.7

46

2

194

7.5

542

72

117

25.7

276

66

61

62

98

36.7

172

69.2

172

83.1

1368

91.9

DSHOV

2–6

16

6.3

184

3.8

100

5

175

8.6

545

28.8

138

1.4

267

19.5

43

32.5

92

15.2

155

34.9

158

56.7

1231

70.5

2RT UP1

2

36

55.6

317

40.7

194

46

468

57.1

645

27.2

241

24.5

506

24.9

375

6.9

278

31.3

1022

4.9

693

6.7

2849

14.3

CUSP5

1–5

10

30.0

238

11.8

140

26

357

18.5

633

24.2

146

31.5

390

19.7

106

10.4

191

25.1

418

16.7

378

21.4

1780

16.7

CARA

2–7

9

22.2

249

27.3

138

18

200

20

774

16.2

181

2.3

458

14.9

172

5.3

186

14

477

1.9

388

5.5

2054

5.6

3RT UM2

3

28

71.4

265

57.4

227

61

364

78.6

591

65

254

46.9

495

68.9

260

50.8

247

47

836

37.4

523

41.5

2054

55.9

2R LC

2

42

2.4

314

5.7

214

6.1

347

2.3

401

0

203

1

335

1.2

206

0

260

3

733

0.3

500

0

2404

0.7

C6 LM1

1–5

12

16.7

217

8.3

130

16.9

352

7.7

538

35.9

214

46.7

314

42.7

90

50

195

20.5

355

50.4

322

50.3

1847

55.1

C7 LM1

1–5

11

0

291

4.5

179

5

414

9.4

721

7.9

285

3.1

382

5.7

151

6

272

9.9

565

8.5

473

6.8

2756

8.5

DW

2–3

11

0

154

5.2

75

16

267

8.2

343

15.7

162

4.9

262

14.9

81

39.5

142

16.9

230

30

192

36.5

1311

38.1

3R LM1

3

34

0

357

6

198

0

337

1.2

604

28.3

377

3.4

429

24.2

238

22.3

242

2.5

871

31.1

741

16.5

3276

6.5

4C LM2

4

9

77.8

284

71.1

225

84.4

381

66.4

639

20.8

244

28.7

345

13.6

138

6.5

225

54.2

484

5.2

447

4.4

2462

8.6

1R LM2

1

31

12.9

318

28

269

20.8

333

11.7

548

39.8

336

9.8

407

32.9

220

35.5

242

46.3

772

31.2

659

38.7

2703

32.8

ODONT

1

25

4.0

246

8

111

0

545

2

639

5.5

260

0.4

462

5

95

2.1

155

6

372

6.2

371

6.5

1787

4.4

MMD

0.104

0.109

0.060

0.326

0.156

0.310

0.566

0.119

0.637

0.687

0.684

SDMMD b

0.002

0.002

0.001

0.001

0.002

0.001

0.002

0.002

0.002

0.002

0.001

2*SDMMD

0.027

0.028

0.027

0.026

0.027

0.027

0.029

0.028

0.027

0.027

0.026

aXH-Xiaohe, WE-Western Europe, NE-Northern Europe, NA-Northern Africa, CM-China-Mongolia, JO-Jomon, RJ-Recent Japan, NS-Northeast Siberia, SS-South Siberia, AA-American Arctic, NWA-Northwest North American Indians, NSAI-North and South American Indians

bSDMMD -Standard deviation

According to the frequency data from Table 7, there are no common trends among the distances between Xiaohe and other ancient Chinese groups. Among all eleven groups, the frequency data of Xiaohe and Jilintai have the smallest MMD score (0.221), followed by the MMD result between Xiaohe and Liushui (0.262). Yingpan is another group with the MMD distance not very far away from Xiaohe (0.361). Otherwise, Miaozigou is most distantly related to Xiaohe (0.735), followed by the Xiawanggang (0.676) and Longxian samples (0.660). Moreover, Xiaohe and the Taojiazhai and the Yanghai samples are distinct, with increasing MMD values of 0.625 and 0.649 respectively.

According to the MMD results listed in Table 8, all distances between Xiaohe and the comparison groups from Western Eurasia are small. Northern Africa is most similar to Xiaohe (0.060). The MMD scores between Xiaohe and Western Europe is 0.104, and with Northern Europe is 0.109. Among the Sino-Chinese groups, South Siberia is more closely related to Xiaohe with the MMD result 0.119, and Jomon also shares a slight distance with Xiaohe (0.156). The Northeast Siberia and the three Native American groups are distantly related to Xiaohe within the MMD values.

In order to visualize the relationships between Xiaohe and the comparison groups, a distance dendrogram was subjected to cluster analysis using Ward’s method (Figs. 4 and 5).
Fig. 4

Cluster analysis of MMD for the Chinese samples using Ward’s method

Fig. 5

Cluster analysis of MMD for Eurasian samples using Ward’s method

Within Fig. 4, there are three primary clusters: Yingpan, Yanghai and Taojiazhai are included in the first cluster. Yingpan and Yanghai are found in the same subcluster, followed by the Taojiazhai sample. Likewise, Jiangjialiang, Mogou, Miaozigou, Longxian, and Xiawanggang are found within the second cluster, with the Jiangjialiang and Mogou, as well as the Miaozigou, Longxian, and Xiawanggang samples respectively making up two subclusters. While Xiaohe, Jilintai, and Liushui are found in the third cluster, Xiaohe and Jilintai are found in the same subcluster, followed by the Liushui sample.

In Fig. 5, the Eurasian comparison groups are shown divided into two main distinct groups: China-Mongolia, Recent Japan, Northeast Siberia, and three Native American groups are included in the first cluster, while Xiaohe, Western Europe, Northern Europe, Northern Africa, Jomon, and South Siberia are found in the other cluster. Within the first cluster, China-Mongolia and Recent Japan, Northeast Siberia and American Arctic, Northwest North American Indians and North and South American Indians are respectively found in three subclusters. For the second cluster, Xiaohe, Northern Europe, Western Europe, and Northern Africa samples firstly cluster together and the second subcluster includes Jomon and South Siberia.

4 Discussion

A general summary of how dental trait variation corresponds to the five peopling scenarios in the Xinjiang area is provided in Fig. 6. This figure is divided between the ten traits that characterize Xiaohe and the other four groups of people in the Xinjiang area. By exploring population relationships based on univariate trait frequencies and bio-distance analyses, the assumptions of the various peopling models can be individually evaluated. Of the ten non-metric traits, only three-rooted upper second molar tends to be more consistent. Five traits of Xiaohe and Jilintai, including Carabelli’s trait on upper first molars, three-rooted upper second molars, Cusp 7 and three-rooted lower first molars, and four-cusped lower second molars are almost consistent with each other. Six traits of Xiaohe and Liushui, including tuberculum on second incisor, Cusp 5 and Carabelli’s trait on upper first molars, three-rooted upper second molars, Cusp 7, and three-rooted lower first molars, are almost consistent with each other. Few traits of Xiaohe exhibit consistency with the other two Xinxiang populations.
Fig. 6

Frequencies of 10 non-metric traits of the tooth crown and root within the Xiaohe and other Xinjiang populations

From the MMD results presented in Table 6, the dental non-metric traits trends in the Xinjiang area are clearly discerned. Xiaohe probably shares some common dental non-metric traits with the Jilintai sample, which indicates that these two groups are likely more closely related genetically than Xiaohe people with other samples, although they are geographically far away from each other. Considering previous anthropological studies that used both dental non-metric and cranial metric/non-metric traits, people from Jilintai were a European and Mongolian mixed group that migrated to Xinjiang from the west during the Bronze Age. The European traits were from neighboring Caucasoid groups, and the Mongolian traits possibly originated in Mongolia or Siberia but not from the Central Plains of China. In the Iron Age, many new people entered this region, settled, and intermarried, and then after this period, these populations migrated westward into Central Asia (Zhang 2010), such that the dental morphological affinities between the Jilintai and Xiaohe samples are likely representative of migration from the west and east already happening in the Bronze Age to early Iron Age periods, with these outside populations arriving in the Xiaohe region.

Liushui is another comparison group that has a relatively close MMD distance to Xiaohe. Previous anthropological research demonstrates that Liushui was also a group consisting of an admixture population deriving from both east and west Eurasia that arrived in southwestern Xinjiang as early as the Bronze Age (Zhang et al. 2014). Considering that the time period of Xiaohe was much later than Liushui, our biodistance study indicates that the common dental traits in both the Liushui and Xiaohe samples maybe were transmitted from the same progenitor, but some traits were also influenced by other groups of people, and this effect becomes more obvious in the Xiaohe sample, which belongs to a later time period. The cluster dendrogram in Fig. 3 also arrives at similar results.

Interestingly, Xiaohe shares the largest MMD distance with Yanghai. This indicates that, although they are geographically close to each other and their time period are almost the same, the groups each inherited a different genetic makeup. The archaeological discoveries at the Yanghai cemetery are very rich and reflect multi-aspect cultural relations with the peripheral regions (Li et al. 2011). A cranial metric study shows that the Yanghai sample is a group of nomadic people, mainly with Caucasoid cranio-facial features, who came from the northern Altai region or western Xinjiang 3500 years ago (Cui et al. 2002). Moreover, Xiaohe and Yingpan share the second largest MMD distance in the Xinjiang area, and they are also geographically close to each other. A cranial metric study of Yingpan indicates that it is a group of people mainly consisting of ancient Europeans dating to the Han-Jin period, but they also inherited a few cranio-facial features from Mongolian, i.e., the brachycephalic type (Chen 2002). We can tell from Fig. 4 that Xiaohe shared some dental non-metric traits with Bronze Age people from Mogou, in Gansu 甘肃 Province. It is probably due to early genetic exchange by their ancestors, owing to their very close geographical distance.

It also indicated that there are some common dental traits among Longxian, Miaozigou, and Xiawanggang, and these differ from the other comparison groups. These dental traits probably represent the typical dental non-metric traits of people living around the Central Plains of China, and they are significantly different from the Xiaohe sample, as indicated in Table 7 and Fig. 4.

The biodistance study of the Western Eurasian and Sino-American populations shown in Table 8 and Fig. 5 emphasizes the importance of Xiaohe’s position in Eurasian dental morphology. The samples that cluster closest with Xiaohe is Northern Africa, then the Western Eurasia group modified by Scott and Turner (1997), and then the other two Western Eurasian groups. Xiaohe is also distinct from the three Native American groups. South Siberia is another sample that is similar to Xiaohe in dental morphological traits because of the lower MMD values.

Genetic analysis of the Xiaohe mummies shows that people of Xiaohe were an admixture population originating from both western and eastern Eurasia (Li et al. 2010). Mitochondrial DNA analysis, which reveals maternal ancestry, shows that the Xiaohe people carried both the East Eurasian haplogroup (C4) and the West Eurasian haplogroups (H and K). The East Eurasian lineage C4, which is the dominant haplogroup found in the remains (58.13%), suggests that the east Eurasian component in the Xiaohe people originated from Siberian populations, especially the southern or eastern Siberian populations. The mtDNA haplogroups H and K are common in Western Europe, suggesting that the West Eurasian component of the maternal ancestry observed in the people of Xiaohe might have a close relationship with Western Europeans. The Y chromosomal DNA analysis, which reveals paternal lineage, shows only the West Eurasian haplogroup R1a1a in the male individuals. All these DNA analysis results are almost confirmed by the MMD results in our study.

The cultural remains discovered in the Xiaohe cemetery suggest that the culture of Xiaohe originated in the Okunev and Sintasha-Petrovka Cultures coming from the South Siberia area, and also there is a suggestion that the culture of Xiaohe is closely related to the Afanasevo Culture, which was the earliest Eneolithic archaeological culture found until now in south Siberia (Guo 2012). This hypothesis is supported by the MMD cluster result in Fig. 4, which exhibits close distance between people from Xiaohe and South Siberia.

5 Conclusion

The Eurasian Steppe provided very suitable conditions for living as well as for the transmission of information and technology, and it also promoted cultural integration. This has resulted in the modern ethnic diversity seen in this region and its great variety of biological subtypes (Khudaverdyan 2013). The Xiaohe region, as a part of the Eurasian Steppe, is an area where people have a variety of genetic origins, as has been shown in previous bioarchaeological research (Li et al. 2010). With reference to dental morphological traits of ancient people in Eurasia, our study provides insight into the complex relationships between the ancient people from Xiaohe and the other comparison groups.

The biodistance results reported in this study indicate that the Xiaohe population was an admixture, showing features mostly resultant from people who had migrated from Europe but who had also exchanged genes with Mongolians: this can be supported by previous historical, craniometric, and DNA analyses (Li et al. 2010). Further, two main interaction spheres, seen through dental non-metric traits, can be identified in the Xinjiang area. The first one comprises Xiaohe, Jilintai, and Liushui, and the second one includes Yanghai and Yingpan, but the reasons that made these groups different have not yet been found by our study, although it is possibly due to how gene flow occurred in the Eurasian area.

In this study, one of the limits to the exploration of the origins of the population in the Xiaohe area is the small sample size. However, the biodistance results reported in our study demonstrate the complexity of the population structure of the Xiaohe cemetery. Additional data from the Xiaohe region and more samples from earlier time periods in the Xinjiang area are still required. Likewise, other factors need to be considered, as well, including material culture studies and linguistics: these could also help to differentiate the Xiaohe population.

Notes

Acknowledgments

We would like to thank Dr. Deborah C. Merrett for her detailed corrections. Thanks are also due to the two reviewers for their constructive suggestions. We also are grateful to Prof. David Cohen for his constructive suggestions and critical revision of this manuscript during editing.

References

  1. Bergman, Folke. 1939. Archaeological Researches in Sinkiang, Especially the Lop Nor Region (Reports from the Scientific Expedition to the North-Western Provinces of China under the Leadership of Dr. Sven Hedin, section 7, no. 1). Stockholm: Thule.Google Scholar
  2. Buikstra, J.E., and D.H Ubelaker. 1994. Standards for data collection from human skeletal remains: proceedings of a seminar at the Field Museum of Natural History, organized by Jonathan Haas (Arkansas Archaeological Survey Research Series 44),15–43. Fayetteville: University of Arkansas.Google Scholar
  3. Chen Liang 陈靓. 2002. Xinjiang Weili xian Yingpan mu di gu ren gu de yan jiu 新疆尉犁县营盘墓地古人骨的研究 (The study on the ancient skulls from the cemetery in Weili County, Xinjiang Province). Bian jiang kao gu yan jiu 边疆考古研究 1: 323–341.Google Scholar
  4. Cui Yinqiu 崔银秋, Duan Ranhui 段然慧, Zhu Hong 朱泓. 2002. Tulufan gu mu zang ren gu yi hai de xian li ti DNA yan jiu 吐鲁番古墓葬人骨遗骸的线粒体DNA分析 (Mitochondrial DNA analysis of human remains in ancient tombs of Turpan area. Bian jiang kao gu yan jiu 边疆考古研究 1: 365–369.Google Scholar
  5. Green, R.F., and J.M. Suchey. 1976. The use of inverse sine transformation in the analysis of non-metric cranial data. American Journal of Physical Anthropology 45: 61–68.CrossRefGoogle Scholar
  6. Guo Wu 郭物. 2012. Xinjiang shi qian wan qi she hui de kao gu xue yan jiu 新疆史前晚期社会的考古学研究 (Archaeological research on the prehistory of Xinjiang). Shanghai: Shanghai gu ji chu ban she.Google Scholar
  7. Harris, E.F., and T. Sjøvold. 2004. Calculation of Smith’s mean measure of divergence for intergroup comparisons using nonmetric data. Dental Anthropology 17 (3): 83–93.Google Scholar
  8. Irish, J.D. 2010. The mean measure of divergence: Its utility in model-free and model-bound analyses relative to the Mahalanobis D2 distance for nonmetric traits. American Journal of Human Biology 22: 378–395.CrossRefGoogle Scholar
  9. Khudaverdyan, A.Y. 2013. Non-metric dental analysis of a Bronze Age population from the Armenian Plateau. Anthropological Review 76 (1): 63–82.CrossRefGoogle Scholar
  10. Lee, Christine. 2007. The Biological Affinities of Neolithic through Modern Period Population from China and Mongolia: The Cranial and Dental Non-metric Trait Evidence. PhD dissertation, Arizona State University.Google Scholar
  11. Li Chunxiang 李春香. 2010. Xiaohe mu di gu dai sheng wu yi hai de fen zi yi chuan xue yan jiu 小河墓地古代生物遗骸的分子遗传学研究 (Molecular genetic analysis of ancient remains from the Xiaohe Cemetery). PhD dissertation, Jilin University.Google Scholar
  12. Li, C., H. Li, Y. Cui, C. Xie, D. Cai, W. Li, V. Mair, Z. Xu, Q. Zhang, I. Abuduresule, L. Jin, H. Zhu, and H. Zhou. 2010. Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age. BMC Biology 8: 1–12.CrossRefGoogle Scholar
  13. Li Xiao 李肖, Lü Enguo 吕恩国, and Zhang Yongbing 张永兵. 2011. Xinjiang Shanshan Yanghai mu di fa jue bao gao 新疆鄯善洋海墓地发掘报告 (Report on the excavation of Yanghai cemetery of Shanshan, Xinjiang). Kao gu xue bao 考古学报 2011.1: 99–166.Google Scholar
  14. Liu Wu 刘武. 1995. Huabei xin shi qi shi dai ren lei ya chi xing tai te zheng ji qi zai xian dai Zhongguo ren qi yuan yu yan hua shang de yi yi 华北新石器时代人类牙齿形态特征及其在现代中国人起源与演化上的意义 (The dental morphology of Neolithic humans in North China and its relationship with modern Chinese origins). Ren lei xue xue bao 人类学学报 14 (4): 360–380.Google Scholar
  15. Liu Wu 刘武 and Zeng Xianglong 曾祥龙. 1996. Shanxi Longxian zhan guo shi dai ren lei ya chi xing tai te zheng 陕西陇县战国时代人类牙齿形态特征 (The dental morphology of the people of Warring States period in Longxian, Shanxi Province). Ren lei xue xue bao 15 (4): 302–314.Google Scholar
  16. Liu Wu 刘武 and Zhu Hong 朱泓. 1995. Miaozigou xin shi qi shi dai ren lei ya chi Feiceliang Tezheng 庙子沟新石器时代人类牙齿非测量特征 (The nonmetric traits of human teeth from Miaozigou Neolithic site). Ren lei xue xue bao 14 (1): 8–20.Google Scholar
  17. Scott, G.R., and C.G. Turner II. 1997. The Anthropology of Modern Human Teeth: Dental Morphology and its Variation in Recent Human Populations. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  18. Scott, G. R., Potter, R. H. Y., Noss, J. F., Dahlberg, A. A., and Dahlberg, T. 1983. The dental morphology of pima indians. American Journal of Physical Anthropology 61 (1): 13–31.CrossRefGoogle Scholar
  19. ShaoXiangqing 绍象清. 1985. Renti Celiang Shouce人体测量手册(Anthropometric Manual), 34–56. Shahghai: Shanghai Lexicographical Publishing House.Google Scholar
  20. Turner, C.G., C.R. Nichol, and G.R. Scott. 1991. Scoring procedures for key morphological traits of the permanent dentition: The Arizona State University dental anthropology system. In Advances in Dental Anthropology, ed. M.A. Kelley and C.S. Larsen, 13–31. New York: Wiley.Google Scholar
  21. Wang Binghua 王炳华. 1992. Tulufan de gu dai wen ming 吐鲁番的古代文明 (The ancient civilization of Turpan). Urummchi: Xinjiang People’s Publishing House.Google Scholar
  22. Xiao Xiaoyong 肖小勇. 2004. Guan yu Xinjiang shi qian yan jiu de tao lun 关于新疆史前研究的讨论 (On the discussion of prehistorical studies of Xinjiang). Xiyu yan jiu 西域研究 2: 74–83.Google Scholar
  23. Yidilisi Abuduresule 伊弟利斯, Li Wenying 李文瑛, and Hu Xingjun 胡兴军. 2007. Xinjiang Luobupo Xiaohe mu di 2003 nian fa jue jian bao 新疆罗布泊小河墓地2003年发掘简报 (Brief report on the excavation of Xiaohe cemetery of Lop Nor, Xinjiang in 2003). Wen wu 文物 2007.10: 4–42.Google Scholar
  24. Zhang Jinglei 张敬雷 2008. Qinghai sheng Xining shi Taojiazhai Han Jin shi qi mu di ren gu yan jiu 青海省西宁市陶家寨汉晋时期墓地人骨研究 (Research on the human skeletons of the Han and Jin Dynasties from the Taojiazhai graveyard in Xining City of Qinghai Province). PhD dissertation, Jilin University.Google Scholar
  25. Zhang Linhu 张林虎. 2010. Xinjiang Yili Jilintai ku qu mu zang ren gu yan jiu 新疆伊犁吉林台库区墓葬人骨研究 (Research on the Jilintai Reservoir cemeteries, Yili County, Xinjiang Province). PhD dissertation, Jilin University.Google Scholar
  26. Zhang Linhu 张林虎, Zhu Hong 朱泓. 2013.Xinjiang Yili Jilintai Kuqu Muzang Rengu Yachi Xingtai Tezheng de Guancha Yu Yanjiu 新疆伊犁吉林台库区墓葬人骨牙齿形态特征的观察与研究(The dental nometric analysis of the residents of Jilintai reservior cemeteries). Xiyu Yanjiu 西域研究 3: 95–105. Google Scholar
  27. Zhang Xu 张旭, Zhu Hong 朱泓, Wang Minghui 王明辉, and Wu Xinhua 巫新华. 2014. Xinjiang Yutian Liushui mu di qing tong shi dai ren lei ya chi fei ce liang xing zhuang 新疆于田流水墓地青铜时代人类牙齿非测量性状 (Bioarchaeological analysis of Bronze Age populations in the Liushui cemetery using dental non-metric traits). Ren lei xue xue bao 人类学学报 33 (4): 460–470.Google Scholar
  28. Zhao Yongsheng 赵永生. 2013. Gansu Lintan Mogou mu di ren gu yan jiu 甘肃临潭磨沟墓地人骨研究 (Research on the human skeletons of the Mogou graveyard, Lintan County, Gansu Province). PhD dissertation, Jilin University.Google Scholar

Copyright information

© Research Center for Chinese Frontier Archaeology (RCCFA) and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Zhu Hong 
    • 1
  • Xu Zhang
    • 2
    • 3
    Email author
  • Li Wenying 
    • 4
  • Abuduresule Yidilisi
    • 4
  1. 1.Research Center for Chinese Frontier ArchaeologyJilin UniversityChangchunChina
  2. 2.Institute of ArchaeologyChinese Academy of Social SciencesBeijingChina
  3. 3.SFU-JLU Joint Center for Bioarchaeological ResearchChangchunChina
  4. 4.Institute of Cultural Relics and Archaeology of XinjiangUrumqiChina

Personalised recommendations