**7. Time required for establishing an agricultural society: the Levant**

The regions listed in **Table 1** went on to complete the establishment of the four independent agricultural societies [28] are compared in **Table 2**. Some of the main changes to be accomplished to become an established agricultural society are listed in **Table 3**.

The independence of the four agricultures is borne out by the diversity of species involved in each case as shown in column 2. Each area developed its own distinct constellation of domesticated species. The last column gives the date at which the complex agriculture-based society appears to have been well established and shows that they were all established within the same 5-millennium time period.

Each of the changes indicated in **Tables 2** and **3** has its own problems, and the order in which they are accomplished may differ from place to place, but all of them must be carried out to complete the development of an agricultural way of life. In


**Table 2.**

*Four agricultural societies developed independently.*


#### **Table 3.**

*Main steps in transition from hunter-gatherer to agricultural societies.*

addition to the genetic changes required to produce a domesticated plant or animal, fundamental changes in technology and social structure are needed. Although the time to domesticate one particular plant may be of the order of a few centuries [19], the total time it takes to change from a hunter-gatherer society to an agricultural one is much longer. Here, we estimate this time scale for the best-studied case, the Middle East, using archeological investigations and studies of wild progenitors of cultivated plants [19]. There is also information on animal domestication that comes from bones found in archeological sites [4, 29]; housing, tool development, and settlement patterns are also available from archeological studies [4, 20]. However, much of the material from earlier archeological studies, while provocative, is of limited use because reliable dating methods are still not perfect.

The earliest agricultural society was developed in the southern Levant, an area that includes southern Syria and Lebanon, Israel, Palestine, Jordan, and the Sinai Peninsula during the cultural-historical time known as the Pre-Pottery Neolithic (PPN) that spanned the years between about 11,700 and 8250 ybp [6]. In the wellstudied Israeli section of the Levant, much of the area was an open grassland with wild cereals and pistachio trees [6]. Local Levant climate history has been derived from speleothems in Israeli caves (at 32°N) [29] that have recorded a proxy signal of the Eastern Mediterranean region. An analysis of the data since 18,000 ybp shows several markedly different climates. The most interesting time for our purposes is the ~3000-year period that has a rainfall of 675–950 mm, almost twice the presentday values, and the Dead Sea reached its maximum level. The onset of this wet episode determined within the accuracy of the time determinations corresponds to the end of the YD. After 8000 ybp, the temperature and rainfall in the Levant became more similar to the current values. The plant remains were combinations of cereals, pulses, and flax and were similar to the plants that appeared later all over

**7**

*Climate Stability and the Origin of Agriculture DOI: http://dx.doi.org/10.5772/intechopen.83344*

estimate of that date.

2000 years.

wind.

the Near East. Three cereals were cultivated: emmer wheat, einkorn wheat, and barley. Cereals alone, however, do not provide all of the nutrition required by man. In the case of the Levant, the cereals were added by legumes (lentils, peas, bitter vetch, and chickpeas) [20]. Sheep and goats were also domesticated and replace gazelles, and other wild games have previously been hunted [19]. During the PPN, the size and complexity of settlements increased by a factor of 14 [20], but the earliest of the PPN sites show some cultural continuity with the preceding final phase of the preagricultural Natufian period (12,500–12,000 ybp). The agriculture was not brought to the region by an invading force due to total absence of evidence for

interpersonal or intercommunity aggression or violence during the PPN.

The earliest evidence of cultivated cereals in the Levant has been dated to ∼ 10,600–10,000 ybp when the remains of emmer and einkorn wheats show the telltale signs of domestication. The fact that such remains were found in several sites during this period implied that the actual beginning of wheat cultivation in this area was earlier, perhaps as early as the first part of the Pre-Pottery Neolithic (PPNA) (11,700–10,500 ybp) [6]. Kislev et al. [30] presented evidence that during this same period figs appear to have been gathered from trees grown intentionally from planted branches. The development of agriculture so soon after the termination of the YD-led Bar-Yosef et al. [6] to suggest that the first experiments in systematic cultivation may have occurred during the YD which ended abruptly ~11,750 ybp. However, they report that no remains of domesticated plants have yet been recovered from the YD itself [6]. Although there is some uncertainty in the date of the beginning of wheat farming, ~11,000\$ ybp is a reasonably conservative

Thus, the development of the earliest agricultural societies would be encouraged by the absence of large century-scale climate variability during a period of at least

Here, we discuss the variations in the Earth's climate derived from two of climate proxy records (CPR): the polar ice cores in Greenland and the sea sediments from

The best and the most discussed of these data banks is from the polar ice cores in Greenland, which contains climate memory of diverse climate variables [31]. The oxygen isotopes in snow characterize temperatures [16, 32], while the dust blown from the deserts and the sea salt blown from the ocean characterize the atmospheric

The records from the Greenland Ice Sheet Project 2 (GISP2) cover the time period from 110,000 ybp to the present, although with differing sampling rates and accuracy. The variability found in these records indicates a nonlinear nature of the climate variations. For example, using a composite of the time series of the Ca, Na, Cl, SO4, K, and Mg ions and a narrowband filtering technique, Mayewski et al. [31] found that between 110,000 and 11,000 years ago there was a variation with a

To take into account the nonstationary and nonlinear character of the climate paleo records, we apply the empirical mode decomposition (EMD) techniques [33], which are especially designed for analyses of nonlinear and nonstationary time series. The EMD represents the data as the sum of a small number of empirical orthogonal modes that have time-variable amplitudes and instantaneous frequencies capturing the nonstationary spectral content of the data. This method employs empirical basis that is changing in time to adapt to the actual variability of the data

**8. When climate was stable on these time scales**

the Cariaco Basin of the Northern coast of South America.

persistent period of 1450 years but with time-varying amplitude.

#### *Climate Stability and the Origin of Agriculture DOI: http://dx.doi.org/10.5772/intechopen.83344*

*Climate Change and Agriculture*

addition to the genetic changes required to produce a domesticated plant or animal, fundamental changes in technology and social structure are needed. Although the time to domesticate one particular plant may be of the order of a few centuries [19], the total time it takes to change from a hunter-gatherer society to an agricultural one is much longer. Here, we estimate this time scale for the best-studied case, the Middle East, using archeological investigations and studies of wild progenitors of cultivated plants [19]. There is also information on animal domestication that comes from bones found in archeological sites [4, 29]; housing, tool development, and settlement patterns are also available from archeological studies [4, 20]. However, much of the material from earlier archeological studies, while provoca-

Tools Projectiles and traps Farming tools, cereal preparation, food storage

Small bands Villages, towns

**Location Species Development** 

Levant Wheat, barley, chickpeas, flax, sheep, goats ~ 9000 ybp China Rice, millet, pigs, silkworms by 9000 ybp Mesoamerica Corn, beans, squash, turkey by 5500 ybp Andean-Amazonian Potato, manioc, guinea pig, llama by 5500 ybp

Domesticated counterparts

**accomplished**

techniques

**Item Hunter-gatherers Agricultural society** Food plants Wild grains, fruit, tubers Domesticated counterparts Animals Many species of wild prey A few domesticated species

Housing Temporary, easy to erect Permanent structures

*Main steps in transition from hunter-gatherer to agricultural societies.*

Clothing Wild animals, vegetable fibers

*Four agricultural societies developed independently.*

Settlement patterns

**Table 3.**

**Table 2.**

tive, is of limited use because reliable dating methods are still not perfect.

The earliest agricultural society was developed in the southern Levant, an area that includes southern Syria and Lebanon, Israel, Palestine, Jordan, and the Sinai Peninsula during the cultural-historical time known as the Pre-Pottery Neolithic (PPN) that spanned the years between about 11,700 and 8250 ybp [6]. In the wellstudied Israeli section of the Levant, much of the area was an open grassland with wild cereals and pistachio trees [6]. Local Levant climate history has been derived from speleothems in Israeli caves (at 32°N) [29] that have recorded a proxy signal of the Eastern Mediterranean region. An analysis of the data since 18,000 ybp shows several markedly different climates. The most interesting time for our purposes is the ~3000-year period that has a rainfall of 675–950 mm, almost twice the presentday values, and the Dead Sea reached its maximum level. The onset of this wet episode determined within the accuracy of the time determinations corresponds to the end of the YD. After 8000 ybp, the temperature and rainfall in the Levant became more similar to the current values. The plant remains were combinations of cereals, pulses, and flax and were similar to the plants that appeared later all over

**6**

the Near East. Three cereals were cultivated: emmer wheat, einkorn wheat, and barley. Cereals alone, however, do not provide all of the nutrition required by man. In the case of the Levant, the cereals were added by legumes (lentils, peas, bitter vetch, and chickpeas) [20]. Sheep and goats were also domesticated and replace gazelles, and other wild games have previously been hunted [19]. During the PPN, the size and complexity of settlements increased by a factor of 14 [20], but the earliest of the PPN sites show some cultural continuity with the preceding final phase of the preagricultural Natufian period (12,500–12,000 ybp). The agriculture was not brought to the region by an invading force due to total absence of evidence for interpersonal or intercommunity aggression or violence during the PPN.

The earliest evidence of cultivated cereals in the Levant has been dated to ∼ 10,600–10,000 ybp when the remains of emmer and einkorn wheats show the telltale signs of domestication. The fact that such remains were found in several sites during this period implied that the actual beginning of wheat cultivation in this area was earlier, perhaps as early as the first part of the Pre-Pottery Neolithic (PPNA) (11,700–10,500 ybp) [6]. Kislev et al. [30] presented evidence that during this same period figs appear to have been gathered from trees grown intentionally from planted branches. The development of agriculture so soon after the termination of the YD-led Bar-Yosef et al. [6] to suggest that the first experiments in systematic cultivation may have occurred during the YD which ended abruptly ~11,750 ybp. However, they report that no remains of domesticated plants have yet been recovered from the YD itself [6]. Although there is some uncertainty in the date of the beginning of wheat farming, ~11,000\$ ybp is a reasonably conservative estimate of that date.

Thus, the development of the earliest agricultural societies would be encouraged by the absence of large century-scale climate variability during a period of at least 2000 years.
