Abstract

The domestication of plants in southwest Asia was an evolutionary process that took place over several millennia in the Early Holocene. During this time domestic species developed distinct traits that distinguish them from their wild counterparts. Current models of plant domestication emphasise the role of genetic selection in the evolution of these traits, viewing these as heritable adaptations that arose in response to selective pressures associated with human cultivation. In cereals, domestication resulted in the evolution of non-shattering rachis and increased grain size, two traits that can be tracked directly in the archaeobotanical record. Measurements of cereal grains from Early Neolithic sites indicate that grain size increase occurred prior to the evolution of non-shattering rachis, and it has been proposed that this reflects selection for larger grains under tillage, signifying pre-domestication cultivation.

In this talk I will report on new results from two Pre-Pottery Neolithic sites in the southern Levant, where well-preserved archaeobotanical evidence supports the hypothesis that cereal evolution was shaped by developmental plasticity as well as genetic selection, and that increased grain size in the Early Holocene is better understood as a plastic response to variation in growing conditions (specifically moisture), rather than a result of genetic selection for increased grain size under cultivation (i.e., tillage).

Please join us in-person in the McDonald Institute seminar room or join online.

https://teams.microsoft.com/l/meetup-join/19%3ameeting_ZDc2MDk1ZGQtNmNkZC00M2U2LTliYjMtN2EyZWE0MDI5ZTAz%40thread.v2/0?context=%7b%22Tid%22%3a%2249a50445-bdfa-4b79-ade3-547b4f3986e9%22%2c%22Oid%22%3a%227c42dde3-f200-49ed-9a81-5aa7e67f945e%22%7d