Què hereta el cervell

Tots els animals tenen un sistema nerviós que els relaciona amb l'entorn, però el cervell humà no té parió. No només percebem l'entorn i som capaços de veure, per exemple, com surt el sol, sinó que a diferència de tota la resta d'ani- mals som capaços de percebre i gaudir de tota la bellesa d'aquesta explosió de llum i color. Tampoc no som els únics que vivim en societats organitzades, però la complexitat i la varietat de la nostra és infinitament superior. Ens comuni- quem amb els nostres congèneres, com d'una manera o una altra fan tots els mamífers, però el nostre llenguatge és capaç de crear també poesia. I colpegem pedres i pals, com la resta de primats, però les nostres mans, guiades pel cervell, també són capaces de crear obres d'art magnífiques. I raonem, som conscients de la nostra pròpia existència i hem fet florir les cultures més variades. El nostre comportament, i fins i tot la nostra forma de pensar i de percebre el món, vénen determinats per l'activitat del cervell i per anys d'evolució [...]

The age of the"Grande Coupure" mammal turnover: New constraints from the Eocene Oligocene record of the Eastern Ebro Basin (NE Spain.)

The Grande Coupure represents a major terrestrial faunal turnover recorded in Eurasia associated with the overall climate shift at the Eocene-Oligocene transition. During this event, a large number of European Eocene endemic mammals became extinct and new Asian immigrants appeared. The absolute age of the Grande Coupure, however, has remained controversial for decades. The Late Eocene-Oligocene continental record of the Eastern Ebro Basin (NE Spain) constitutes a unique opportunity to build a robust magnetostratigraphy- based chronostratigraphy which can contribute with independent age constraints for this important turnover. This study presents new magnetostratigraphic data of a 495-m-thick section (Moià-Santpedor) that ranges from 36.1 Ma to 33.3 Ma. The integration of the new results with previous litho- bio- and magnetostratigraphic records of the Ebro Basin yields accurate ages for the immediately pre- and post-Grand Coupure mammal fossil assemblages found in the study area, bracketing the Grande Coupure to an age embracing the Eocene-Oligocene transition, with a maximum allowable lag of 0.5 Myr with respect to this boundary. The shift to drier conditions that accompanied the global cooling at the Eocene-Oligocene transition probably determined the sedimentary trends in the Eastern Ebro Basin. The occurrence and expansion of an amalgamated-channel sandstone unit is interpreted as the forced response of the fluvial fan system to the transient retraction of the central-basin lake systems. The new results from the Ebro Basin allow us to revisit correlations for the controversial Eocene-Oligocene record of the Hampshire Basin (Isle of Wight, UK), and their implications for the calibration of the Mammal Palaeogene reference levels MP18 to MP21.