Department of Anthropology, Florida State University, Tallahassee, 32306, USA.
J Hum Evol. 2009 Nov;57(5):597-607. doi: 10.1016/j.jhevol.2008.10.008. Epub 2009 Feb 28.
Earlier observations of the virtual endocast of LB1, the type specimen for Homo floresiensis, are reviewed, extended, and interpreted. Seven derived features of LB1's cerebral cortex are detailed: a caudally-positioned occipital lobe, lack of a rostrally-located lunate sulcus, a caudally-expanded temporal lobe, advanced morphology of the lateral prefrontal cortex, shape of the rostral prefrontal cortex, enlarged gyri in the frontopolar region, and an expanded orbitofrontal cortex. These features indicate that LB1's brain was globally reorganized despite its ape-sized cranial capacity (417cm(3)). Neurological reorganization may thus form the basis for the cognitive abilities attributed to H. floresiensis. Because of its tiny cranial capacity, some workers think that LB1 represents a Homo sapiens individual that was afflicted with microcephaly, or some other pathology, rather than a new species of hominin. We respond to concerns about our earlier study of microcephalics compared with normal individuals, and reaffirm that LB1 did not suffer from this pathology. The intense controversy about LB1 reflects an older continuing dispute about the relative evolutionary importance of brain size versus neurological reorganization. LB1 may help resolve this debate and illuminate constraints that governed hominin brain evolution.
早期对弗洛里斯人（ Homo floresiensis ）的模式标本 LB1 的虚拟内颅骨的观察结果进行了回顾、扩展和解释。详细描述了 LB1 大脑皮层的七个衍生特征：枕叶位于尾部，月牙形沟位于头部，颞叶尾部扩展，外侧前额叶皮质形态先进，前额叶皮质的形状，额极回增大，眶额回扩大。这些特征表明，尽管 LB1 的颅腔容量（417cm³）与猿类相当，但大脑整体上进行了重组。因此，神经重组可能构成了将认知能力归因于弗洛里斯人的基础。由于其颅腔容量很小，一些研究人员认为 LB1 代表了一个患有小头症或其他疾病的智人个体，而不是一个新人种。我们回应了对我们早期关于小头症个体与正常个体的研究的关注，并再次确认 LB1 没有患有这种疾病。关于 LB1 的激烈争论反映了关于大脑大小与神经重组的相对进化重要性的一个旧的持续争议。LB1 可能有助于解决这场争论，并阐明控制人类大脑进化的限制。
