Stephen Shennan - Academia.edu (original) (raw)
Papers by Stephen Shennan
Quaternary Research, 2019
The focus of this paper is the Neolithic of northwest Europe, where a rapid growth in population ... more The focus of this paper is the Neolithic of northwest Europe, where a rapid growth in population between ~5950 and ~5550 cal yr BP is followed by a decline that lasted until ~4950 cal yr BP. The timing of the increase in population density correlates with the local appearance of farming and is attributed to the advantageous effects of agriculture. However, the subsequent population decline has yet to be satisfactorily explained. One possible explanation is the reduction in yields in Neolithic cereal-based agriculture due to worsening climatic conditions. The suggestion of a correlation between Neolithic climate deterioration, agricultural productivity, and a decrease in population requires testing for northwestern Europe. Data for our analyses were collected during the Cultural Evolution of Neolithic Europe project. We assess the correlation between agricultural productivity and population densities in the Neolithic of northwest Europe by examining the changing frequencies of crop a...
As originally conceived, this chapter aimed to examine the problems of relating technical and soc... more As originally conceived, this chapter aimed to examine the problems of relating technical and social information in the archaeology of earlier hominids, and specifically to examine the number of individual cultural traits that could be identified in early material. It has been widened to take a broader look at social models in human evolution, but I try to follow the same theme: how many lines of evidence do we have about early hominids that can be related as knowledge? Scrutiny of these may cast light on relationships between social structure and the more directly cultural (archaeological) evidence. Gamble's quotation above indicates some of the profound changes in approaches to the Palaeolithic: these have had even greater consequences for its early stages, because of the great alterations in framework and new finds of fundamental importance (e.g. the 4.5 million-year-old hominids reported by White et al. 1994). Plainly a social phase has come to dominate archaeology, after earlier cultural, economic and processual focuses. But for early times there are difficulties in applying it because the record is so technological. It is not surprising that technology has made something of a fight-back since Gamble's comment, but it is more socially dressed (Sinclair and Schlanger 1990). Static, classificatory, typology is out. A dynamic approach to technology as social practice is in contrast much favoured, perhaps suspiciously so: Reynolds (1991) has decried it as a new tyranny. Ideally the several aspects should be brought together, as in the 'palaeoethnology' of studies at Pincevent (Leroi-Gourhan and Brezillon 1972), but for the earliest Palaeolithic that is less possible. The strands of evidence-if we are honest-militate against an integrated approach. The fossils lend themselves to studies of locomotion and diet, and next towards being arranged in taxonomies-and, with more difficulty, phylogenies. Ecological studies aim to set this information into a context of life-of animals, plants and interspecies relations. They suffer from a surfeit of free play, because animal behaviour in an environment is actually very flexible. Conventional environmental science hits a similar problem-it is
Trends in Plant Science, 2021
Ornamental plants are unique as their domestication is not associated with the need for food secu... more Ornamental plants are unique as their domestication is not associated with the need for food security but rather for human aesthetic, visual and other sensory attractiveness. The new extended evolutionary theory-proposing that inheritance and evolution is not by genes alone but is affected by the environment and human socio-cultural processes, and by gene-culture coevolution-makes it possible to elucidate plants' evolution and domestication. 2 Ornamental plant domestication and breeding is a specific aesthetics-driven dimension of human niche construction, that coevolved with socioeconomic changes and new scientific technologies. The new era of ornamental plants is dependent on the application of new technologies and symbolic-to-material asset shifts, with a foundation in a human sense of beauty and aesthetic values.
Journal of World Prehistory, 2021
The Italian peninsula offers an excellent case study within which to investigate long-term region... more The Italian peninsula offers an excellent case study within which to investigate long-term regional demographic trends and their response to climate fluctuations, especially given its diverse landscapes, latitudinal range and varied elevations. In the past two decades, summed probability distributions of calibrated radiocarbon dates have become an important method for inferring population dynamics in prehistory. Recent advances in this approach also allow for statistical assessment of spatio-temporal patterning in demographic trends. In this paper we reconstruct population change for the whole Italian peninsula from the Late Mesolithic to the Early Iron Age (10,000–2800 cal yr BP). How did population patterns vary across time and space? Were fluctuations in human population related to climate change? In order to answer these questions, we have collated a large list of published radiocarbon dates (n = 4010) and use this list firstly to infer the demographic trends for the Italian pen...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2020
Population matters. Demographic patterns are both a cause and a consequence of human behaviour in... more Population matters. Demographic patterns are both a cause and a consequence of human behaviour in other important domains, such as subsistence, cooperation, politics and culture. Demographers interested in contemporary and recent historical populations have rich data at their fingertips; the importance of demography means many interested parties have gathered demographic data, much of which is now readily available for all to explore. Those interested in the demography of the distant past are not so fortunate, given the lack of written records. Nevertheless, the emergence in recent years of a new interest in the demography of ancient populations has seen the development of a range of new methods for piecing together archaeological, skeletal and DNA evidence to reconstruct past population patterns. These efforts have found evidence in support of the view that the relatively low long-term population growth rates of prehistoric human populations, albeit ultimately conditioned by carryi...
Antiquity, 1999
How can archaeologists evaluate the ‘cost of production’ in prehistory? Stephen Shennan explores ... more How can archaeologists evaluate the ‘cost of production’ in prehistory? Stephen Shennan explores ethnographic examples, Ricardo's Law of Comparative Advantage and archaeological evidence from the eastern Alps in a stimulating discussion of Bronze Age production and exchange.
Knowledge of the origin and spread of farming has been revolutionised in recent years by the appl... more Knowledge of the origin and spread of farming has been revolutionised in recent years by the application of new scientific techniques, especially the analysis of ancient DNA from human genomes. In this book, Stephen Shennan presents the latest research on the spread of farming by archaeologists, geneticists and other archaeological scientists. He shows that it resulted from a population expansion from present-day Turkey. Using ideas from the disciplines of human behavioural ecology and cultural evolution, he explains how this process took place. The expansion was not the result of 'population pressure' but of the opportunities for increased fertility by colonising new regions that farming offered. The knowledge and resources for the farming 'niche' were passed on from parents to their children. However, Shennan demonstrates that the demographic patterns associated with the spread of farming resulted in population booms and busts, not continuous expansion.
<p>Blue lines represent breadth, red lines represent length and green lines represent depth... more <p>Blue lines represent breadth, red lines represent length and green lines represent depth. The dashed line is the mean value for all measurements. The raw osteometrics and their proportional change are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141873#pone.0141873.t002" target="_blank">Table 2</a>.</p
... catalogue ! Notice. 35.00 € Ajouter au panier. Ranking, resource and exchange: aspect of the ... more ... catalogue ! Notice. 35.00 € Ajouter au panier. Ranking, resource and exchange: aspect of the archaeology of early european society. Auteur ...
Page 1. PREHISTORIC EUROPE TIMOTHY CHAMPION CLIVE GAMBLE STEPHEN SHENNAN ALASDAIR WHITTLE Page 2.... more Page 1. PREHISTORIC EUROPE TIMOTHY CHAMPION CLIVE GAMBLE STEPHEN SHENNAN ALASDAIR WHITTLE Page 2. PREHISTORIC EUROPE Page 3. Page 4. PREHISTORIC EUROPE Timothy Champion Clive Gamble ...
The Archaeology of Human Ancestry, 2005
The object of this chapter is to sketch out the basis of an archaeological approach to examining ... more The object of this chapter is to sketch out the basis of an archaeological approach to examining the interrelationships between cultural traditions, inequality and the maintenance of social groups through time. The approach is intended to be of general relevance, but the discussion will be concentrated on the anthropology of foraging societies, since, for a variety of reasons, these are generally agreed to be of most relevance to providing a perspective for the analysis and discussion of inferred patterns of long-term human evolution. The idea that there are links between patterns of social inequality and how groups define and organize themselves is familiar enough, but that these should be connected in some way to cultural traditions is perhaps less obvious. The fact that it now seems a worthwhile issue to raise can be ascribed to the development of what Durham (1990, 1992) has called 'evolutionary culture theory', in effect the study of 'cultural descent with modification', based on recent accounts of the mechanisms of cultural transmission and the factors affecting it (Cavalli-Sforza and Feldman 1981, Boyd and Richerson 1985, and see Introduction). However, with the exception of a recent paper by Aldenderfer (1993), the subject of hierarchy and inequality has not been much discussed in this context, even though debates about their nature and extent are regarded by many as central to any understanding of long-term social change. The aim of this chapter is to outline a model which suggests that hierarchy and the cultural transmission process are in some respects closely linked, even in foraging societies, which have tended to be seen as relatively egalitarian. CULTURAL TRADITIONS It has long been argued that what differentiates humans from other animals is the existence of cultural traditions, which mean that cultural responses to change have largely superseded genetic ones. The presumption has always been that such cultural traditions were adaptive, in that they enabled people to survive more successfully, and therefore gave a selective advantage in terms of reproductive success over populations which did not have such traditions. A great deal of attention has been devoted to identifying the functional-adaptive role that particular traditions, for example, the production of artefacts, might have had, but the processes by which they are handed on from one
Antiquity, 1995
A gelatin capsule is widely used as a device for oral administration of granular/powdered materia... more A gelatin capsule is widely used as a device for oral administration of granular/powdered materials or small amounts of liquid materials in animal experiments. In this study, we investigated the insulin-and glucagon-related parameters following oral administration of gelatin capsules to beagle dogs since a gelatin capsule is made of protein composed of many amino acids as known to stimulate insulin or glucagon secretion. Gelatin capsules (1/2 ounces in size) were administered once orally to three male beagle dogs at the dose level of 0.29 and 1.67 g/kg as gelatin and the plasma levels of insulin, glucagon, glucose, non-esterified fatty acids (NEFA), total ketone bodies (KB) and alanine were determined before dosing and for up to 4 hr after dosing. Plasma insulin, glucagon and alanine levels increased immediately after dosing and subsequently plasma NEFA and total KB levels decreased. Most of these changes disappeared by 4 hr after dosing. No effects on plasma glucose levels were noted. In conclusion, a single oral administration of gelatin capsules increased plasma insulin and glucagon levels transiently and altered plasma levels of some biochemical parameters in dogs. These results might imply that attention should be paid to their own effect on the insulin and glucagon secretion at conducting animal experiments using a lot of gelatin capsules.
If archaeology is to take a leading role in the social sciences, new theoretical and methodologic... more If archaeology is to take a leading role in the social sciences, new theoretical and methodological advances emerging from the natural sciences cannot be ignored. This requires considerable retooling for archaeology as a discipline at a population scale of analysis. Such an approach is not easy to carry through, especially owing to historically contingent regional traditions; however, the knowledge gained by directly addressing these problems head-on is well worth the effort. This paper shows how population level processes driving cultural evolution can be better understood if mathematical and computational methods, often with a strong element of simulation, are applied to archaeological datasets. We use computational methods to study patterns and process of temporal variation in the frequency of cultural variants. More specifically, we will explore how lineages of lithic technologies are transmitted over time using a well-analysed and chronologically fine-grained assemblage of Cent...
Mammalian social learning: …, 1999
... Second, we know from ethnography that small hunter-gatherer groups are made up of close kin, ... more ... Second, we know from ethnography that small hunter-gatherer groups are made up of close kin, so it is reasonable to ... Peer interaction of this kind provides increasing opportunities for horizontaltransmission of information and practices among children, a very different mode of ...
This database contains information collected during the AHRB-funded project "The Origin and ... more This database contains information collected during the AHRB-funded project "The Origin and Spread of Neolithic Plant Economies in the Near East and Europe", directed by Stephen Shennan (UCL) and James Conolly (UCL, now Trent University, Canada) with collaboration from James Steele (UCL) and Sue Colledge (UCL). The dataset consists of four tables: (1) sites.csv, which contains the site name [P], country of location and the reference used for creating the data record; (2) phases.csv, which contains the site names [S], a phase code [P], and the broad cultural designation of each phase; (3) samples.csv, containing the phase code [P1], a taxon code [P2] and a field indicating whether the sample is likely contaminated or not; (4) a taxa table linking the taxa code [P/S] to full taxonomic details. The dataset is intended to be used in a relational database, with [P] designating a primary key, and [S] a secondary (linking) key
Quaternary Research, 2019
The focus of this paper is the Neolithic of northwest Europe, where a rapid growth in population ... more The focus of this paper is the Neolithic of northwest Europe, where a rapid growth in population between ~5950 and ~5550 cal yr BP is followed by a decline that lasted until ~4950 cal yr BP. The timing of the increase in population density correlates with the local appearance of farming and is attributed to the advantageous effects of agriculture. However, the subsequent population decline has yet to be satisfactorily explained. One possible explanation is the reduction in yields in Neolithic cereal-based agriculture due to worsening climatic conditions. The suggestion of a correlation between Neolithic climate deterioration, agricultural productivity, and a decrease in population requires testing for northwestern Europe. Data for our analyses were collected during the Cultural Evolution of Neolithic Europe project. We assess the correlation between agricultural productivity and population densities in the Neolithic of northwest Europe by examining the changing frequencies of crop a...
As originally conceived, this chapter aimed to examine the problems of relating technical and soc... more As originally conceived, this chapter aimed to examine the problems of relating technical and social information in the archaeology of earlier hominids, and specifically to examine the number of individual cultural traits that could be identified in early material. It has been widened to take a broader look at social models in human evolution, but I try to follow the same theme: how many lines of evidence do we have about early hominids that can be related as knowledge? Scrutiny of these may cast light on relationships between social structure and the more directly cultural (archaeological) evidence. Gamble's quotation above indicates some of the profound changes in approaches to the Palaeolithic: these have had even greater consequences for its early stages, because of the great alterations in framework and new finds of fundamental importance (e.g. the 4.5 million-year-old hominids reported by White et al. 1994). Plainly a social phase has come to dominate archaeology, after earlier cultural, economic and processual focuses. But for early times there are difficulties in applying it because the record is so technological. It is not surprising that technology has made something of a fight-back since Gamble's comment, but it is more socially dressed (Sinclair and Schlanger 1990). Static, classificatory, typology is out. A dynamic approach to technology as social practice is in contrast much favoured, perhaps suspiciously so: Reynolds (1991) has decried it as a new tyranny. Ideally the several aspects should be brought together, as in the 'palaeoethnology' of studies at Pincevent (Leroi-Gourhan and Brezillon 1972), but for the earliest Palaeolithic that is less possible. The strands of evidence-if we are honest-militate against an integrated approach. The fossils lend themselves to studies of locomotion and diet, and next towards being arranged in taxonomies-and, with more difficulty, phylogenies. Ecological studies aim to set this information into a context of life-of animals, plants and interspecies relations. They suffer from a surfeit of free play, because animal behaviour in an environment is actually very flexible. Conventional environmental science hits a similar problem-it is
Trends in Plant Science, 2021
Ornamental plants are unique as their domestication is not associated with the need for food secu... more Ornamental plants are unique as their domestication is not associated with the need for food security but rather for human aesthetic, visual and other sensory attractiveness. The new extended evolutionary theory-proposing that inheritance and evolution is not by genes alone but is affected by the environment and human socio-cultural processes, and by gene-culture coevolution-makes it possible to elucidate plants' evolution and domestication. 2 Ornamental plant domestication and breeding is a specific aesthetics-driven dimension of human niche construction, that coevolved with socioeconomic changes and new scientific technologies. The new era of ornamental plants is dependent on the application of new technologies and symbolic-to-material asset shifts, with a foundation in a human sense of beauty and aesthetic values.
Journal of World Prehistory, 2021
The Italian peninsula offers an excellent case study within which to investigate long-term region... more The Italian peninsula offers an excellent case study within which to investigate long-term regional demographic trends and their response to climate fluctuations, especially given its diverse landscapes, latitudinal range and varied elevations. In the past two decades, summed probability distributions of calibrated radiocarbon dates have become an important method for inferring population dynamics in prehistory. Recent advances in this approach also allow for statistical assessment of spatio-temporal patterning in demographic trends. In this paper we reconstruct population change for the whole Italian peninsula from the Late Mesolithic to the Early Iron Age (10,000–2800 cal yr BP). How did population patterns vary across time and space? Were fluctuations in human population related to climate change? In order to answer these questions, we have collated a large list of published radiocarbon dates (n = 4010) and use this list firstly to infer the demographic trends for the Italian pen...
Philosophical Transactions of the Royal Society B: Biological Sciences, 2020
Population matters. Demographic patterns are both a cause and a consequence of human behaviour in... more Population matters. Demographic patterns are both a cause and a consequence of human behaviour in other important domains, such as subsistence, cooperation, politics and culture. Demographers interested in contemporary and recent historical populations have rich data at their fingertips; the importance of demography means many interested parties have gathered demographic data, much of which is now readily available for all to explore. Those interested in the demography of the distant past are not so fortunate, given the lack of written records. Nevertheless, the emergence in recent years of a new interest in the demography of ancient populations has seen the development of a range of new methods for piecing together archaeological, skeletal and DNA evidence to reconstruct past population patterns. These efforts have found evidence in support of the view that the relatively low long-term population growth rates of prehistoric human populations, albeit ultimately conditioned by carryi...
Antiquity, 1999
How can archaeologists evaluate the ‘cost of production’ in prehistory? Stephen Shennan explores ... more How can archaeologists evaluate the ‘cost of production’ in prehistory? Stephen Shennan explores ethnographic examples, Ricardo's Law of Comparative Advantage and archaeological evidence from the eastern Alps in a stimulating discussion of Bronze Age production and exchange.
Knowledge of the origin and spread of farming has been revolutionised in recent years by the appl... more Knowledge of the origin and spread of farming has been revolutionised in recent years by the application of new scientific techniques, especially the analysis of ancient DNA from human genomes. In this book, Stephen Shennan presents the latest research on the spread of farming by archaeologists, geneticists and other archaeological scientists. He shows that it resulted from a population expansion from present-day Turkey. Using ideas from the disciplines of human behavioural ecology and cultural evolution, he explains how this process took place. The expansion was not the result of 'population pressure' but of the opportunities for increased fertility by colonising new regions that farming offered. The knowledge and resources for the farming 'niche' were passed on from parents to their children. However, Shennan demonstrates that the demographic patterns associated with the spread of farming resulted in population booms and busts, not continuous expansion.
<p>Blue lines represent breadth, red lines represent length and green lines represent depth... more <p>Blue lines represent breadth, red lines represent length and green lines represent depth. The dashed line is the mean value for all measurements. The raw osteometrics and their proportional change are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141873#pone.0141873.t002" target="_blank">Table 2</a>.</p
... catalogue ! Notice. 35.00 € Ajouter au panier. Ranking, resource and exchange: aspect of the ... more ... catalogue ! Notice. 35.00 € Ajouter au panier. Ranking, resource and exchange: aspect of the archaeology of early european society. Auteur ...
Page 1. PREHISTORIC EUROPE TIMOTHY CHAMPION CLIVE GAMBLE STEPHEN SHENNAN ALASDAIR WHITTLE Page 2.... more Page 1. PREHISTORIC EUROPE TIMOTHY CHAMPION CLIVE GAMBLE STEPHEN SHENNAN ALASDAIR WHITTLE Page 2. PREHISTORIC EUROPE Page 3. Page 4. PREHISTORIC EUROPE Timothy Champion Clive Gamble ...
The Archaeology of Human Ancestry, 2005
The object of this chapter is to sketch out the basis of an archaeological approach to examining ... more The object of this chapter is to sketch out the basis of an archaeological approach to examining the interrelationships between cultural traditions, inequality and the maintenance of social groups through time. The approach is intended to be of general relevance, but the discussion will be concentrated on the anthropology of foraging societies, since, for a variety of reasons, these are generally agreed to be of most relevance to providing a perspective for the analysis and discussion of inferred patterns of long-term human evolution. The idea that there are links between patterns of social inequality and how groups define and organize themselves is familiar enough, but that these should be connected in some way to cultural traditions is perhaps less obvious. The fact that it now seems a worthwhile issue to raise can be ascribed to the development of what Durham (1990, 1992) has called 'evolutionary culture theory', in effect the study of 'cultural descent with modification', based on recent accounts of the mechanisms of cultural transmission and the factors affecting it (Cavalli-Sforza and Feldman 1981, Boyd and Richerson 1985, and see Introduction). However, with the exception of a recent paper by Aldenderfer (1993), the subject of hierarchy and inequality has not been much discussed in this context, even though debates about their nature and extent are regarded by many as central to any understanding of long-term social change. The aim of this chapter is to outline a model which suggests that hierarchy and the cultural transmission process are in some respects closely linked, even in foraging societies, which have tended to be seen as relatively egalitarian. CULTURAL TRADITIONS It has long been argued that what differentiates humans from other animals is the existence of cultural traditions, which mean that cultural responses to change have largely superseded genetic ones. The presumption has always been that such cultural traditions were adaptive, in that they enabled people to survive more successfully, and therefore gave a selective advantage in terms of reproductive success over populations which did not have such traditions. A great deal of attention has been devoted to identifying the functional-adaptive role that particular traditions, for example, the production of artefacts, might have had, but the processes by which they are handed on from one
Antiquity, 1995
A gelatin capsule is widely used as a device for oral administration of granular/powdered materia... more A gelatin capsule is widely used as a device for oral administration of granular/powdered materials or small amounts of liquid materials in animal experiments. In this study, we investigated the insulin-and glucagon-related parameters following oral administration of gelatin capsules to beagle dogs since a gelatin capsule is made of protein composed of many amino acids as known to stimulate insulin or glucagon secretion. Gelatin capsules (1/2 ounces in size) were administered once orally to three male beagle dogs at the dose level of 0.29 and 1.67 g/kg as gelatin and the plasma levels of insulin, glucagon, glucose, non-esterified fatty acids (NEFA), total ketone bodies (KB) and alanine were determined before dosing and for up to 4 hr after dosing. Plasma insulin, glucagon and alanine levels increased immediately after dosing and subsequently plasma NEFA and total KB levels decreased. Most of these changes disappeared by 4 hr after dosing. No effects on plasma glucose levels were noted. In conclusion, a single oral administration of gelatin capsules increased plasma insulin and glucagon levels transiently and altered plasma levels of some biochemical parameters in dogs. These results might imply that attention should be paid to their own effect on the insulin and glucagon secretion at conducting animal experiments using a lot of gelatin capsules.
If archaeology is to take a leading role in the social sciences, new theoretical and methodologic... more If archaeology is to take a leading role in the social sciences, new theoretical and methodological advances emerging from the natural sciences cannot be ignored. This requires considerable retooling for archaeology as a discipline at a population scale of analysis. Such an approach is not easy to carry through, especially owing to historically contingent regional traditions; however, the knowledge gained by directly addressing these problems head-on is well worth the effort. This paper shows how population level processes driving cultural evolution can be better understood if mathematical and computational methods, often with a strong element of simulation, are applied to archaeological datasets. We use computational methods to study patterns and process of temporal variation in the frequency of cultural variants. More specifically, we will explore how lineages of lithic technologies are transmitted over time using a well-analysed and chronologically fine-grained assemblage of Cent...
Mammalian social learning: …, 1999
... Second, we know from ethnography that small hunter-gatherer groups are made up of close kin, ... more ... Second, we know from ethnography that small hunter-gatherer groups are made up of close kin, so it is reasonable to ... Peer interaction of this kind provides increasing opportunities for horizontaltransmission of information and practices among children, a very different mode of ...
This database contains information collected during the AHRB-funded project "The Origin and ... more This database contains information collected during the AHRB-funded project "The Origin and Spread of Neolithic Plant Economies in the Near East and Europe", directed by Stephen Shennan (UCL) and James Conolly (UCL, now Trent University, Canada) with collaboration from James Steele (UCL) and Sue Colledge (UCL). The dataset consists of four tables: (1) sites.csv, which contains the site name [P], country of location and the reference used for creating the data record; (2) phases.csv, which contains the site names [S], a phase code [P], and the broad cultural designation of each phase; (3) samples.csv, containing the phase code [P1], a taxon code [P2] and a field indicating whether the sample is likely contaminated or not; (4) a taxa table linking the taxa code [P/S] to full taxonomic details. The dataset is intended to be used in a relational database, with [P] designating a primary key, and [S] a secondary (linking) key
Knowledge of the origin and spread of farming has been revolutionised in recent years by the appl... more Knowledge of the origin and spread of farming has been revolutionised in recent years by the application of new scientific techniques, especially the analysis of ancient DNA from human genomes. In this book, Stephen Shennan presents the latest research on the spread of farming by archaeologists, geneticists and other archaeological scientists. He shows that it resulted from a population expansion from present-day Turkey. Using ideas from the disciplines of human behavioural ecology and cultural evolution, he explains how this process took place. The e xpansion was not the result of 'population pressure' but of the opportunities for increased fertility by colonising new regions that farming offered. The knowledge and resources for the farming 'niche' were passed on from parents to their children.