| |
Rezumat articol ediţie STUDIA UNIVERSITATIS BABEŞ-BOLYAI
În partea de jos este prezentat rezumatul articolului selectat. Pentru revenire la cuprinsul ediţiei din care face parte acest articol, se accesează linkul din titlu. Pentru vizualizarea tuturor articolelor din arhivă la care este autor/coautor unul din autorii de mai jos, se accesează linkul din numele autorului. |
|
| |
Rezumat: Establishing environmental context is crucial in human palaeontology because it
provides both the essential contextual framework as well as clues to external
influences, evolutionary drivers and trends. This is a particular issue with the first
known hominins to have emerged beyond Africa approximately 1.75 Ma ago at the
site of Dmanisi in Georgia. Morphologically the Dmanisi hominins, although variable,
closely resemble the very earliest members of the genus Homo in Africa. The question
then arises about how early humans, adapted over millions of years to tropical and
savanna environments in Africa, coped with the temperate, harsher conditions of the
southern Caucasus. We do not, however, understand the prevailing climate conditions
in this part of the world very well, except for limited environmental information from
the Eurasian faunal assemblage that suggests a mosaic of forest and open landscape.
It has been suggested that possibly the ancient Dmanisi environment was warm
enough to support some C4 savanna grasses. Here we show that this was not the
case; based on stable carbon isotope analyses of ename, the floral cover was entirely
C3, although there is a hint that this situation may have changed later. Although the
distinguishing power of C3 and C4 flora is lacking, a combination of carbon and oxygen
isotope ratios serves to distinguish the niches of some fauna. For instance the
influence of closed forest habitats is suggested for bears, which have the lowest 13C/12C
ratios. Preliminary high-resolution data from tooth crowns show that δ18O fluctuated
by 3-4‰ seasonally, and small but patterned seasonal trends can be distinguished in
δ13C amongst both grazing and browsing fauna.
|
|
