la cordonneriekordonnier.fr/img/pdf/ts_c05_clad-homo.pdf · 2016-02-13 · swansc q.pilzingleben...

Tous les fossiles de la lignée humaine sont bipèdes.

Théorie ancienne et fausse d'un redressement progressif.

450 → 1300

Pan Paranthropus Homo

Y5

Chemicals found in any animal come from what it ingests, such as plants. Plants turn sunlight into energy using photosynthesis, but they rely on two slightly different forms of the process. The two approaches add different amounts of the isotope carbon 13 to the plants' leaves. Bushes, shrubs and trees have less carbon 13 in their fruit or leaves than savanna grasses. The chemicals in the food eaten by P. robustus, including the isotope, were incorporated into the enamel of the hominid's permanent teeth as they formed.

Sponheimer and his colleagues used a laser to remove samples from each of the four P. robustus teeth, leaving only small marks on the precious specimens. Then, they analyzed the carbon isotope ratio in the samples. The researchers report that Paranthropus ate a variety of foods, perhaps grasses, tubers and even animals – and what they ate varied seasonally and from hominid to hominid.

Les cladogrammes des élèves

1470 1813

habilis ss rudolfensis

Paranthropus

Les origines géographiques

Habilis et erectus

Erectus

L'Ève mitochondriale

Sapiens