The question of how humans managed to achieve an increase in fertility in the Neolithic, around 8000 years ago, despite the evident difficulties and risks accompanying birth, is one of the most important questions of human evolution because without that demographic success the further development of civilization would not be possible. Although the key agents of this population increase were the prehistoric mothers and their babies, the scientific investigation of their role in this process was rare. The vision of the BIRTH project is to move prehistoric babies and their mothers from the marginalized position of scientific investigation and to underline the importance of motherhood for the rise of human civilization.
In order to provide a holistic approach in understanding of the prehistoric fertility BIRTH investigated skeletal, nutritive and cultural factors influencing the increase of birth rates in the period between 10000 and 5000 BC in the Balkans, an important route for the Neolithisation of Europe. We investigated motherhood before and during the farming expansion in Europe at its very beginning, when the first Neolithic communities started to expand towards and across the Balkans (around 6200 BC). BIRTH's main aim was to provide biological evidence of prehistoric birthing, to investigate population changes during the beginning of the European Neolithic and to study probable cultural and nutritional causes of the fertility increase. Through the analysis of human, animal, plant and archaeological remains and through computer simulation we made conclusions about fertility increase at the beginning of the Neolithisation of Europe, revealing unknown data about how this process, which changed Europe forever, looked like from the motherhood perspective.
The BIRTH's most important conclusion, indicated by the increase of the number of stress lines in tooth cementum, is that Neolithic females experienced increased physiological stress compared to the Mesolithic females, which present the first biological evidence for the increase of fertility. Increase is also indicated by our computer simulation which shows that fertility of the Neolithic populations in the Balkans must have been high, probably 8-10 children born by an average woman. Probably this sudden increase of the number of births influenced their health as it is indicated by our finding of more health degradation of Neolithic females compared to males. The Neolithic also brought a novel type of baby gruel, probably a mixture of milk and cereals, served to babies with carefully crafted bone spoons, on which we found bite marks of their milky teeth. This new weaning food allowed mothers to breastfeed shorter and to introduce weaning food earlier which may have influence on their fertility. Additionally, new baby food could make profound changes in the organisation of the baby care, allowing much easier contribution of other members of society to help in baby feeding and care. Therefore BIRTH suggested that changes in the system of cooperative breeding (caring for babies by non-parental individuals) caused by the appearance of the new baby gruel, was an important pillar for the female fertility increase with the Neolithic.
