Although there is evidence for early and rapid domestication of pigs in the lower Yangtze , the adoption of domesticated animals commonly used in dairying did not occur until the late Holocene . The prevalence of lactase persistence phenotypes within China remains low today , although there are slightly higher frequencies in the North . The evidence for long-term dietary change within South Asia is particularly complex with considerable spatial and temporal variation. The earliest pottery and domestic rice are present by 9 kya, but evidence for significant sedentary villages and agricultural dependence occurs only after 4 kya following the mid-Holocene movement of crops from both the Western Eurasia and China . There is evidence for the independent domestication of cattle in the Indus region ca. 7 kya and convergent evolution for lactase persistence in South Asia, with the highest frequencies in the northwest parts of the region, but very low frequencies in southern and eastern areas of the Indian subcontinent . It is also notable that Indian pastoralists maintain greater stature than higher caste individuals, which has been attributed to milk consumption . The question of body size variation as a reflection of diet and health in the past has been of long-standing interest to bio-archaeologists. While documented declines in Neolithic estimated statures have been linked to lower predicted statures based on genetics , adult body size also reflects developmental plasticity and life history variation . Stature itself is not really a trait, but rather a consequence of growth, which ultimately reflects variation in strategies for energy allocation throughout development. Body mass likewise indicates investment in lean and fat tissue, although unlike stature, these can respond to ecological stresses through adult life. Improved growth is generically a good marker of health because many aspects of somatic maintenance benefit from better growth in early life, plastic plant pot whereas defense against pathogens and early reproduction reduces energy for linear growth and lean tissue deposition.

Applying a life history perspective to growth provides insights into the likely role of infectious disease and pathogens in reductions in stature in prehistory, as there are multiple routes to generate the adult phenotype which extend beyond diet but also include allocation of energy to immune function or reproduction, potentially mediated by fat deposition .A comparison of trends in stature across the past 10 kya in other regions is presented in Fig. 3. Southern Europe is characterized by a general decline between 10 and 6 kya, followed by relative stability through the mid-Holocene . In Central Europe, there is a marked and significant increase in male stature between 8 and 5 kya, and a general increase in female stature across the same time frame . Both males and females in Northern Europe are also characterized by a general increase in stature from 7 kya, with males peaking ca. 3 kya and females ca. 2 kya . Stature trends across the same time frame in the Nile are more variable and show no specific long term trends, while in China statures are generally consistent throughout the Holocene, except for a decline among females after 3 kya . A contrasting pattern is observed in South Asia where there is a significant decline in both male and female stature throughout the Holocene. A regional comparison of Holocene body mass trends illustrates a consistent pattern of initial decline in Southern Europe followed by a period of relative stability. In Central Europe, there is a general increase in male body mass between 4.5 and 2 kya, while female mass is relatively stable throughout the Holocene. In Northern Europe, there are early Holocene declines in both male and female body mass that reach their low point approximately 5 kya and are followed by increases by 2 kya. When these patterns are contrasted with other regions, we see relatively little change in the Nile Valley, while in South Asia male body masses increase in the first half of the Holocene in a period where female mass appears to decline. Here, estimated male masses fall considerably after 4 kya.

In China, there appears to be relative stability in body mass in the early part of the Holocene, followed by increases among males from 5 to 2 kya, and among females from 3 to 1 kya. Noting that the most significant long-term increases in stature occur in Central and Northern Europe where there is evidence for strong selection acting upon lactase persistence during the mid-Holocene, we consider specific trends in sub-regions of Northern Europe, Britain, southern Scandinavia, and the eastern Baltics, over the past 8,000 y . In Britain, there is relatively minor and non-significant temporal variation in stature through time, while male body mass generally increases from ca. 5 to 2 kya. In Scandinavia, there are marked and significant increases in male stature between 7 and 4 kya.Body masses in the region are consistent among early Holocene males but females show a decrease through the mid-Holocene. Both sexes show increases in body mass between 5 and 2 kya, but the trend is more pronounced among females. In the Baltics increases in stature are expressed in both males and females between 6 and 2 kya while body masses are relatively consistent throughout the Holocene. To investigate the spatiotemporal patterning of body size variation throughout Europe in greater detail, we generated heat maps of mean statures and body masses . The results demonstrate fairly uniformstature across Europe before 10 kya and a general decline between 10 to 6 kya, followed by increases that are most pronounced in Northern Europe and Southern Scandinavia. Body mass trends follow a broadly similar pattern, with much of Europe characterized by estimated body masses above 65 kg before 10 kya, followed by declines in much of Western Europe through to 6 kya. Increases in body mass are observed in Central Europe from 6 to 4 kya and across most of Northern Europe from 4 kya to the present. The period from 10 to 6 kya is predominantly before the transition to agriculture in central and northern regions but includes hunter-gatherers, farmers, and others with variable or transitional subsistence strategies, suggesting that further analyses with an expanded dataset are required to contextualize this trend.

In this study, we investigated long-term trends in human stature and body mass relative to late Pleistocene and Holocene cultural change in seven different regions. We analyzed data by chronological and geographical information rather than cultural labels, given the significant spatiotemporal and regional variation in cultural characteristics attributed to terms such as the Neolithic, opting instead to discuss the broader timescales upon which the process of the transition to domesticated plants and animals was enacted. The results demonstrated that in most regions body size decreased before the earliest manifestations of agriculture, regional patterns of phenotypic variation over time are variable, and this spatiotemporal variation in stature and body mass is not directly associated with the onset of the Neolithic. Given their timing, these trends cannot simply be explained by subsistence changes related to the reliance on domesticated plants and animals. We also noted recent phenotypic diversification that is most pronounced in the last 2,000years,nursery pots which requires further study but may stem from a combination of demographic expansion, genetic diversification, and socio-economic inequality. It is worth noting that the long-term trends in the Levant, where the earliest transition to agriculture was observed as a complex process over millennia , demonstrated relatively stable stature and body mass trends over time. The Levant is a region characterized by long-term population continuity and the in situ domestication of numerous species of indigenous plants and animals over an extended period of the terminal Pleistocene and early Holocene . The transition to agriculture in this region represented a long period of mixed hunting and gathering and cultivation of crops and domesticates that were well adapted to local environmental conditions. Similarly, there was no significant change in stature through time in China after plant domestication, and an increase in body mass among males during the later Holocene. This is a region that is also characterized by population continuity, local domesticates, a very long period of mixed foraging and farming rather than an abrupt agricultural transition, and high levels of environmental productivity. It is important to note that our approach to comparing population trends by region may confound local impacts of migrations and gene flow, such as the well documented increase in steppe ancestry among northern Europeans, which may have influenced north-south gradients in human stature , and similar population movements in other regions likely influenced the complexity and timing of cultural and phenotypic changes. In South Asia, for example, we noted long-term reductions in stature and body mass throughout the Holocene. The region, however, exhibits a high degree of ecological diversity and is characterized by the adoption of different domesticates that originated in East Asia, Western Asia, and Africa in different regions of the Indian Subcontinent.

Similarly, in the Nile Valley, another region characterized by the adoption of plant and animal domesticates from other regions, results are highly variable and likely confounded by the complexity of migration history in the region. At present, there are insufficient data to match aDNA evidence for ancestry with direct phenotypic measures on the broad scale presented in this paper. However, it is likely that underlying genetic variation and changes in the sociocultural environment, including diet, underpin phenotypic change. Further research will be required to clarify long-term spatiotemporal trends in phenotypic and genetic variation. We also aimed to test the LGH by determining whether the geographic and temporal timing of selection for LP phenotypes is associated with increases in stature and body mass. The most significant mid-Holocene increases in stature and body mass occurred in Northern Europe between 7 and 4 kya and these were preceded by increases in stature in Central Europe that occurred between ∼8 and 5 kya. These regions are linked in providing evidence for mid-Holocene selective sweeps in genetic variants associated with LP, providing preliminary support for the LGH. Within Northern Europe, modest increases in body mass were noted in Britain among males, but the most significant trends toward increased stature and body mass were found in the Baltic and southern Scandinavian regions. Heat map results demonstrate how the current patterns of stature and mass variation in Europe were established throughout the mid to late Holocene. While size increases were noted in regions where there is evidence of natural selection in response to dairying, we noted different trends among males and females with more significant increases in stature generally expressed among men and more significant variation in body mass among women. We suggest this is explained by greater plasticity among men, particularly in stature, in response to environmental and cultural fluctuations, while women’s phenotypic variation is better able to buffer environmental stress via sexual dimorphism in body mass that reflect lifelong differences in energetics and somatic investment . There is evidence that males show greater stunting in response to early life under nutrition , which would lead to greater variation in adult male statures. While skeletal methods of body mass estimation do not generally reflect late-life accrual of body mass , both lean mass and fat mass are components of maternal fitness, and substantial variability in these tissues emerges prior to reproduction, suggesting that body mass variation is more directly linked to female fitness than stature . Phenotypic plasticity may have also been expressed most strongly late in development, where IGF-I factors in dairy milk may have directly fueled growth differences and sexual dimorphism . In general, we note that while the timing of size increases corresponds with selective sweeps in lactase persistence , it is unclear whether phenotypic variation reflects underlying genetic variation or whether phenotypic plasticity precedes later genetic adaptation, but there is growing evidence that the latter is an important mechanism of adaptability . Overall, our results provide provisional evidence for greater phenotypic stability in regions of in situ domestication and where the transition to agriculture was gradual over millennia. The dispersal of farmers into novel environments where foreign domesticates may have struggled to establish appears to have led to greater phenotypic diversity in human populations.