The Upright Ape: A New Origin of the Species

by Aaron G. Filler, MD, PhD

Figure 5-1 Hox Control of Cranial Embryogenesis and the Homology of the Hyoid

Hox and Dlx genes in cranial embryogenesis

Figure 5-1 – Morphogenetics and Homology of the Hyoid Bone


The advent of modern morphogenetics has made it possible to reveal genetic positional markers that provide a fixed identity for each of the various skull components. The hyoid bone (Hy) played a key roll in the development of the ideas of unity of body plan (Geoffroy) and homology (Owen). It is specified by Hox a2, Hox b2, and Dlx 1&2, Dlx 5&6 and Dlx 3&7 genes as shown where the grid lines intersect in part B of the figure.

Figure credit -

From: Kuratani, S. (2005a). Craniofacial development and the evolution of the vertebrates: the old problems on a new background. Zoological Science 22(1): 1-19. Figure reproduced by permission of the Zoological Society of Japan.

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