Integrating the genotype and phenotype in hominid paleontology

Abstract

Competing interpretations of human origins and evolution have recently proliferated despite the accelerated pace of fossil discovery. These controversies parallel those involving other vertebrate families and result from the difficulty of studying evolution among closely related species. Recent advances in developmental and quantitative genetics show that some conventions routinely used by hominid and other mammalian paleontologists are unwarranted. These same advances provide ways to integrate knowledge of the genotype into the study of the phenotype. The result is an approach that promises to yield a fuller understanding of evolution below the family level.

Patterns of craniofacial variation and taxonomic diversity in the South African Cercopithecidae fossil record

“…"(C)" is the abbreviation for canine. Roosmalen and van Roosmalen, 2003;Craul et al, 2007), interpreting the evolution of that diversity is still largely in the realm of paleontological studies (see Kimbel and Rak, 1993;Plavcan, 1993;Rose and Bown, 1993;Hlusko, 2004Hlusko, , 2016Hlusko et al, 2016). Our analyses show that many measurements of the cranium and face of fossil South African papionins are highly correlated with each other, suggesting a high level of cranial phenotypic integration in this group similar to what is reported for extant OWMs.…”

“…Quantitative genetics has helped illuminate our understanding of the genetic architecture that underlies continuously variable phenotypes of the vertebrate skeleton, including the cranium (e.g., Cheverud and Buikstra, 1981;Cheverud, 1982;Leamy et al, 1999;Hlusko, 2004;Sherwood et al, 2008aSherwood et al, , 2008bRoseman et al, 2010). The vertebrate cranium is comprised of three major developmental components: the splanchnocranium (comprising the jaws, hyoid, and middle ear bones) the chondrocranium (supporting the brain and sensory organs) and the dermatocranium (comprising the roof and sides of the cranium) (Kardong, 1995;Hildebrand and Goslow, 2001;Webster and Webster, 2013).…”

Quantitative genetics of modern human cranial variation

“…Most often these traits are treated as individual independent characters of equal phyletic value. Implicit in such considerations, however, is the assumption that the genetic contribution to morphological variation is high and equivalent across traits, and that phenotypic and genetic correlations between traits, irrespective of their magnitude, introduce negligible confounding effects in phylogenetic reconstruction (Hlusko, 2004).…”

Morphological integration in human skull and its possible role in etiogenesis of neuropsychiatric disorders: Deciphering the link between evolution, development and disease

“…Plausibly, these variations accumulated in the long course of evolution (33)(34)(35), through assimilation of co-variances (34,35) and epigenetic changes (36) in the gross and genetic structure of a population respectively, implied morphological integration (34,37). The inclusion of variations in the skull components in the course of evolution might have subjected a population to acquire and propagate multiple errors at molecular level (3) and to express these as aberrant genotypes and phenotypes (38), setting basis for etiogenesis of certain neuropsychiatric disorders (10,12,18,7).…”