ically , ▁it ▁does ▁demonstrate ▁how ▁the ▁D man isi ▁sk ull s ▁provide ▁evidence ▁for ▁the ▁large ▁range ▁of ▁morph ological ▁variation ▁in ▁early ▁H omo . ▁ ▁The ▁sk ull s ▁discovered ▁at ▁D man isi ▁are ▁the ▁smallest ▁bra ined ▁spec im ens ▁to ▁be ▁assigned ▁to ▁H omo ▁ere ct us ▁and ▁they ▁are ▁among ▁the ▁smallest ▁bra ined ▁H omo ▁foss ils ▁in ▁general . ▁Because ▁the ▁five ▁sk ull s ▁are ▁composed ▁of ▁males ▁and ▁females , ▁as ▁well ▁as ▁younger ▁and ▁older ▁individuals , ▁they ▁provide ▁an ▁excellent ▁glance ▁into ▁the ▁range ▁of ▁variation ▁present ▁in ▁early ▁H omo ▁around ▁ 1 . 7 5 ▁My a . ▁Some ▁research ers ▁have ▁claimed ▁that ▁the ▁small ▁bra ined , ▁primitive ▁nature ▁of ▁the ▁sk ull s ▁pre cludes ▁them ▁from ▁the ▁H . ▁ere ct us ▁species , ▁instead ▁opt ing ▁to ▁design ate ▁them ▁as ▁a ▁separate ▁species ▁H . ▁ge org icus . ▁O thers ▁argue ▁that ▁the ▁unique ▁mix ▁of ▁H . ▁hab ilis - like ▁tra its ▁and ▁H . ▁ere ct us - like ▁tra its ▁demonstrate ▁how ▁this ▁branch ▁of ▁early ▁H omo ▁was ▁a ▁single , ▁gradually ▁evol ving ▁line age . ▁Right m ire ▁et ▁al . ▁have ▁remarked ▁that ▁attempting ▁to ▁establish ▁arbitrary ▁boundaries ▁between ▁H . ▁hab ilis ▁and ▁H . ▁ere ct us ▁is ▁difficult ▁when ▁the ▁D man isi ▁sk ull s ▁represent ▁a ▁step ▁along ▁the ▁grad ual ▁evolution ▁of ▁the ▁line age