Factors that influenced dramatic and permanent change in human subsistence practices must be considered in order to gain a good understanding of the Mesolithic-Neolithic transition.
Since subsistence, whether hunting and gathering or farming, relies so much on favourable environmental conditions, climatic factors have been examined here at key points in the transition to the Neolithic across Europe. Significant changes in temperature and precipitation have been found to coincide with the earliest evidence of farming, with the initial spread of farming to the west, and with the arrival of the Neolithic in Scotland. For the most part, these changes have been shown to be favourable to each of these three events, although the nature of climate shifts in Scotland is debated (Tipping, 1995, Anderson et al., 1998, Macklin et al., 2000, Bonsall et al., 2002b, Langdon et al., 2003, Richards and Schulting, 2006, Schulting, 2010).
The end of the last Ice Age at c.10,000 BP was shortly followed by the earliest indications across Europe of the pre-pottery Neolithic A (PPNA), as defined by Kenyon (1952), at 11,700-10,500 cal BP in the Southern Levant (Kenyon, 1952, Kuijt and Goring-Morris, 2002). This is the first indication of a settled Neolithic culture that grew crops and hunted wild animals (Kenyon, 1955). Pre-pottery Neolithic B populations followed these initial settlements at 10,500-8250 BP, with the earliest examples of animal domestication (Kuijt and Goring-Morris, 2002). As the names suggest, these cultures were defined as Neolithic because of their subsistence practices, but they preceded later ceramic producing groups. It is pertinent that the onset of farming should coincide with the retreat of glacial cover: the warmer temperatures may have made possible the development of agricultural technology and, therefore, the permanent settlement of communities.
Large-scale climate change may have encouraged the spread of the Neolithic culture from its origins in The Fertile Crescent as well as encouraging its inception. At around 8200 BP, proxy records indicate that massive environmental change was produced by a climatic event affecting the Northern hemisphere (Alley et al., 1997, Veski et al., 2004). Ice core and sedimentary records suggest that this change came in the form of sudden altering of oceanic and atmospheric circulation and an influx of freshwater into the North Atlantic from Lake Ammersee (Ellison et al., 2006). The event resulted in cooler, arid conditions, with a relative drop in global temperatures (Alley and Ágústdóttir, 2005). It has been argued that this cold
11 event was the catalyst that expanded farming cultures from The Fertile Crescent to Eastern Europe as farmers suffered drought and, in response, sought more favourable climates and developed new irrigation technology (Weninger et al., 2006). Despite the chronological correlation of the expansion of the Neolithic and the 8200 BP cooling event, and the knowledge that global climate change can affect population demography, more work is required to prove causality (Budja, 2007).
As the Neolithic culture spread East through Europe, a hiatus in its progress occurred in the 5th century BC. While sedentary farming cultures had reached France by 5400-4900 BC, the earliest signs of the Neolithic in neighbouring Britain, Ireland, Denmark and Sweden are not evident until 4100-3800 BC (Bonsall et al., 2002b). This ‘late’ introduction of agriculture to these areas was associated with significant climate change in Scotland, England, Netherlands, Sweden and Finland (Bonsall et al., 2002b). There are several lines of evidence that support this assertion. In Mainland Europe, analysis of macro- and microfossils in peat from the Netherlands identified several species of plant and fungi that are characteristic of dry hydrological conditions, indicating a shift away from the typical damp climate of the area (Dupont, 1986). Sediment analyses in Lake Bysjön, Southern Sweden, shows a lowering in the water level and therefore drier conditions between 4800 and 2600 BC (Digerfeldt, 1988). These shifts to drier conditions in inland Europe occur at the same time as a drier climate in Scotland, as indicated by peat bog analyses (Tipping, 1995). This drier climate made the environment more conducive to crop growing and raising animals and, therefore, could arguably have been an important factor in the onset of the Neolithic culture in Britain.
On a local scale, there is debate regarding possible climate changes at the onset of the Neolithic in Scotland. Evidence derived from plant macrofossils and humification data can be used to argue in favour of the theory that Scotland’s climate became wetter and colder at 5850 BP (Langdon et al 2003). This is evidence from only one 43 ha site; however, and we should be cautious when applying this to the whole of Scotland. When considering the scope of scientific data Schulting (2010) argues that advocates of the ‘drier and warmer’ climate change model ignore the evidence against this theory. While some studies suggest this dry period may have begun later (Anderson, 1998) or shifted to wetter conditions sooner (Tipping, 1995, Anderson, 1998), the general consensus is for a shift to drier climateat the transition period which extended into the Neolithic period. Evidence of a warmer environment comes from a variety of sources. Species of beetle were identified in peat that
12 favour relatively warm climes (Girling, 1984). δ18 O analysis of speleothem calcite and the comparison of the width of tree rings suggests that average temperatures in North Europe may have increased by up to 2°C during the transition (Briffa, 1994). Bonsall et al. (2002a) collated previously published peat humification data from Anderson (1998) and data from charcoal, pollen and woodland decline analyses (Macklin et al., 2000) to conclude that a relatively dry period occurred in Scotland at 4100 BC which continued into the Neolithic period until at least 3200 BC.
The overall climate change experienced in Scotland and areas further afield may also be responsible for some of the changes to the landscape during the Mesolithic-Neolithic transition. Woodland, made up of elm, pine and hazel was characteristic of the Mesolithic period; however, tree cover began to decline at approximately 3000 BC. Some have argued that the decline in tree cover and the appearance of larger and more frequent clearings are evidence of human activity; Mesolithic fire ecology was among the first land manipulations to aid subsistence practices by clearing large areas of land quickly and efficiently (Innes and Blackford, 2003). However, charcoal concentrations and pollen data from Oban, Scotland indicate that the changes in plants and trees are as a result of associated climate change (Macklin et al., 2000). Macklin et al. (2000) suggested that trees which were not adaptable to warm climates died off and were replaced by plants which required open space and sunlight and, additionally, that the interpretation of charcoal and palynological records may overemphasise the impact that humans had on the Scottish environment prior to 3000 BC.
The assertion that human intervention alone cannot account for the large-scale decline in tree cover at the onset of the Neolithic is logical. Brown (1997) reconsidered pollen diagrams to challenge the notion that the late Mesolithic landscape was dominated by thick forest. He argued that early farmers most probably opportunistically occupied natural clearings, and so intentional deforestation was much less common than previously thought. This being said, such a large shift in climate towards a warmer and drier environment cannot be ignored as a probable factor in the changes to the late Mesolithic and early Neolithic landscapes across Scotland and Europe. Milder climates are much more favourable when growing crops and raising animals, and therefore must be considered as one of the many inter-connected factors that contributed to the cultural change from hunting and gathering to farming practices.
The Neolithic period is associated with massive changes in lifestyle and subsistence, so its drivers and origins have been an important topic of research for many years. A changing
13 climate has been identified as coinciding with the Neolithic, and it has been debated as to whether this was the major driving force of agriculture, or if humans were operating outside of climatic influence. Identifying the nuances of these environmental changes has proved difficult. While it is widely accepted that there was a global climate shift to cooler and drier temperatures at 8200 BP that may have been beneficial to the very first agricultural communities in the Middle East, evidence for climate change at around 5800 BP in Western Europe is conflicting. This conflicting evidence may be indicative of small scale climate changes, or of an uncertain chronology in the climate proxies. Further research into climate change in the UK around the time of the transition, including improving the chronological resolution of sedimentary sample sequences, would shed some light on the matter.