Great ape skeletal collections: Making the most of scarce and irreplaceable resources in the digital age

Abstract

Information about primate genomes has re-emphasized the importance of the great apes (Pan, Gorilla, and Pongo) as, for most purposes, the appropriate comparators when generating hypotheses about the most recent common ancestor of the hominins and panins, or the most recent common ancestor of the hominin clade. Great ape skeletal collections are thus an important and irreplaceable resource for researchers conducting these types of comparative analyses, yet the integrity of these collections is threatened by unnecessary use and their availability is threatened by financial pressures on the institutions in which the collections reside. We discuss the general history of great ape skeletal collections, and in order to get a better sense of the utility and potential of these important sources of data we assemble the equivalent of a biography of the Powell-Cotton Collection. We explore the history of how this collection of chimpanzee and gorilla skeletons was accumulated, how it came to be recognized as a potentially important source of comparative information, who has made use of it, and what types of data have been collected. We present a protocol for collecting information about each individual animal (e.g., which bones are preserved, their condition, etc.) and have made that information about the Powell-Cotton Collection freely available in an online relational database (Human Origins Database, www.humanoriginsdatabase.org). As an illustration of the practical application of these data, we developed a tabular summary of ontogenetic information about each individual (see Appendices A and B). Collections like the PowellCotton are irreplaceable sources of material regarding the hard-tissue evidence and recent history of the closest living relatives of modern humans. We end this contribution by suggesting ways that curators and the researchers who use and rely on these reference collections could work together to help preserve and protect them so that future generations can use and benefit from these priceless resources. Am J Phys Anthropol 57:2-32,

Sagittal crest formation in great apes and gibbons

“…Among the taxa investigated in this study, males show a higher frequency of sagittal cresting than do females. These results are consistent with patterns of cranial growth beyond dental maturity and with spheno-occipital fusion being delayed in gorillas and orangutans (Randall, 1943;R€ ohrer-Ertl, 1988;Leutenegger & Masterson, 1989a,b;Masterson & Leutenegger, 1990Uchida, 1996;Hens, 2003Hens, , 2005Balolia et al 2013;Gordon et al 2013;Balolia, 2015).…”

“…; Gordon et al. ; Balolia, ), in conjunction with the need to increase muscle attachment area, have important applications for reconstructing the social behaviour of extinct primate taxa. In particular, if the timing of sagittal crest development in males is associated with a male reproductive strategy characterised by intense intrasexual competition across primates, examination of sagittal crest emergence and associated scaling relationships in fossil assemblages may allow us to begin to reconstruct the nature of intrasexual male competition in those extinct hominin taxa that display evidence of a sagittal crest.…”

Niche Partitioning in Sympatric Gorilla and Pan from Cameroon: Implications for Life History Strategies and for Reconstructing the Evolution of Hominin Life History

“…A recent review details the history of the collection and provides a summary of the developmental status (eruption, sutures, epiphysial fusion) of the specimens collected [51]. Although geographically relatively restricted when compared to other major primate collections, the material at the Powell-Cotton Museum still emanates from a large geographic area.…”

Transparency, usability, and reproducibility: Guiding principles for improving comparative databases using primates as examples

“…Even a trait as seemingly straightforward as body mass may generate substantial errors (beyond resolution and precision of the scales used) when data using different definitions of “adult” are lumped together . In a study of ape morphology, 28% of chimpanzee skeletons and 38% of gorilla skeletons with adult dentition had bones that were still growing and likely had not yet reached adult mass . Thus, despite not being fully grown, these individuals would have been classified as adults if dentition were used as the defining characteristic for adulthood.…”

“…39 In a study of ape morphology, 28% of chimpanzee skeletons and 38% of gorilla skeletons with adult dentition had bones that were still growing and likely had not yet reached adult mass. 40 Thus, despite not being fully grown, these individuals would have been classified as adults if dentition were used as the defining characteristic for adulthood. Another trait for which a range of definitions has been applied is "weaning age," which in primates can include age at first intake of solid food (within the first weeks or months of life); observations of conflict over access to the nipple; the ability to survive as an orphan; or the age at cessation of nipple contact, 41,42 which in extreme cases can average 6.5 years (Bornean orangutan, Pongo pygmaeus wurmbii 43 ).…”