Roca dels Bous (archaeological site) interesting archaeological site indeed. Furthermore, it is to be noted that the samples used for the 14C AMS dating were obtained from deep strata at the site. The oldest Neanderthal sites known in the nearby areas date back to around 40,000 BP. The first settlements attributed to “anatomically modern” Homo sapiens sapiens in Northern Spain are dated around 39,000-38,000 BP. All this would suggest that Neanderthals could have persisted in this particular area longer than previously believed, preceding the arrival of the first Homo sapiens to the area. Research work began in 1988. This wide period of time has contributed
Kinetic isotope effect at which the substitution occurs. Interpretation of the leaving group kinetic isotope effects had been difficult at first due to significant contributions from temperature independent factors. Kinetic isotope effects at the α-carbon can be used to develop some understanding into the symmetry of the transition state in S2 reactions, although this kinetic isotope effect is less sensitive than what would be ideal, also due to contribution from non-vibrational factors. A secondary kinetic isotope effect is observed when no bond to the isotopically-labeled atom in the reactant is broken or formed. Secondary kinetic isotope effects tend to be much smaller than