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Biology subjects

Eisenmann, S.

Publications and source records attributed to Eisenmann, S..

2 recordsLinked to original sources

Human mobility at Tell Atchana (Alalakh) during the 2nd millennium BC: integration of isotopic and genomic evidence

The Middle and Late Bronze Age Near East, a period roughly spanning the second millennium BC (ca. 2000-1200 BC), is frequently referred to as the first international age, characterized by intense and far-reaching contacts between different entities from the eastern Mediterranean to the Near East and beyond. In a large-scale tandem study of stable isotopes and ancient DNA of individuals excavated at Tell Atchana (Alalakh), situated in the northern Levant, we explore the role of mobility at the capital of a regional kingdom. We generated strontium isotope data for 53 individuals, oxygen isotope data for 77 individuals, and added ancient DNA data from 9 new individuals to a recently published dataset of 28 individuals. A dataset like this, from a single site in the Near East, is thus far unparalleled in terms of both its breadth and depth, providing the opportunity to simultaneously obtain an in-depth view of individual mobility and also broader demographic insights into the resident population. The DNA data reveals a very homogeneous gene pool, with only one outlier. This picture of an overwhelmingly local ancestry is consistent with the evidence of local upbringing in most of the individuals indicated by the isotopic data, where only five were found to be non-local. High levels of contact, trade, and exchange of ideas and goods in the Middle and Late Bronze Ages, therefore, seem not to have translated into high levels of individual mobility detectable at Tell Atchana.

genetics

Worker body size but not its age influences phototaxis in a bumblebee (Bombus terrestris, L.)

We studied phototaxis, the directional movement relative to light, in the bumble bee Bombus terrestris. We first developed and validated a MATLAB based system enabling reliable high-resolution tracking of a bee and a measurement of her distance relative to a changing LED light source. Using this system we found in all our experiments that workers show positive phototaxis. The strength of the phototactic response was influenced by body size but not age, and this effect was significant when the light source was weak. In a separate experiment, foragers showed stronger phototactic response compared to nurses only in one of two trials in which they were larger and tested with weak light intensity. The evidence that phototaxis is associated with size-based division of labor in the bumble bee and with age-related division of labor in the honey bee, lends credence to response threshold models implicating the response to light in the organization of division of labor in cavity dwelling social insects.

animal behavior and cognition