לוח שנה משולב

Jerusalem, Ramla and Tiberias were the three most important cities in southern Bilad al-Sham- Greater Syria- during the early Islamic period (7th through 11th centuries).
Jerusalem - Bayt al-Maqdis, the first of the qiblas (direction to Mecca), the third most important city in Islam after Mecca and Medina - needs little explanation for its role in the geo-political map of the period. The buildings on the Temple Mount/al-Haram al-Sharif, especially the Dome of the Rock and the Aqsa mosque, are proof of Islam's intimate connection to this city.
Ramla, a new capital founded on the sands of the Coastal Plain, was developed to the detriment of neighboring Ludd. Although damaged, the impressive remains of the White Mosque in the middle of the modern city stand testimony to its past glory.
The adoption of Tiberias as a provincial capital, nevertheless, needs elaboration. Located west of the Sea of Galilee - not on a crossroads like Beth Shean (the pre-Islamic provincial capital), but built on a long and narrow strip of land and of difficult climate, Tiberias was nevertheless chosen as district capital sometime after its capture in 635. Until recently, the lack of clear archaeological remains of monumental architecture associated with the early Islamic period only added to the open questions regarding the character of this capital. Now the Friday mosque of Tiberias has been identified in the middle of the ancient Roman-Byzantine city centre. It is one of impressive dimensions, with a layout and with evidence of ornamentation reminiscent of no less than the Great Mosque in the capital of the Umayyad caliphate- Damascus.

The ability of a developing organism to accommodate novel environmental challenges is
essential to its potential to evolve and can promote the emergence of developmental
novelties. Current understanding of developmental modifications, however, is largely based
on comparisons between organisms, an approach that does not address the potential role of
novel challenges in driving developmental innovation.
To address this gap we developed an experimental framework for confronting the
development of the fly, D. melanogaster, with a challenge for which no specific response
could have likely been selected during the evolutionary history of the fly (novel challenge).
At the same time it allows the study of forces and processes that may use inherent plasticity
to drive and propagate variations across generations.
Analysis of larval development in response to the challenge revealed three layers of striking phenomena: Rapid physiological adaptation to a novel challenge, trans-generational epigenetic inheritance of the modified course of development, and signaling-like erasure of
the inherited state.
These results demonstrate an important role of developmental plasticity in the ability of multi-cellular organisms to accommodate evolutionary novel challenges without necessarily relying on genetic variations or "pre-designed" solutions. The transient inheritance of the modified course of development provides an opportunity for genetic or epigenetic stabilization of the altered state at later generations and sets the stage for further co-option and emergence of phenotypic diversity.