Costly teeth? Gestation length in primates suggests that neonate dentition is not expensive to produce

Author ORCID Identifier

Karen Samonds:https://orcid.org/0000-0003-3597-9215

Publication Title

Anatomical Record

ISSN

19328486

E-ISSN

43955

Document Type

Article

Abstract

Variation in the relationship between gestation length and body mass can arise because different types of tissue require varying amounts of energy to build, and not all species build such tissues in the same proportions. Given that a pregnant female has a finite amount of energy, trade-offs between investment in different tissues may occur. Here we examine if dental precocity accounts for variation in primate gestation length. If true, this could explain why folivorous species with precocial dentition have longer gestation lengths than predicted by neonatal brain and body mass. We compiled data on gestation length, neonate and adult female body and brain mass from the literature. We used published postcanine eruption schedules at 4 months of age and measured the total occlusal area as dental endowment to approximate dental precocity at birth. Species with embryonic delay in growth or altricial neonates were not considered because they represent grade shifts regarding gestation length. Consequently, our data were biased toward Simiiformes and Old World monkeys, specifically. We performed a phylogenetic generalized least squares regression (pGLS) of neonate brain mass in relation to neonate body mass, and a second pGLS with dental endowment as an additional predictor variable. Including dental endowment in the pGLS did not improve the model. Dental endowment did not systematically impact primate gestation length. Concordant with results from previous studies, this indicates that the energetically expensive period of tooth mineralization may occur postnatally. More data are required to examine if the results are typical across primates.

First Page

2476

Last Page

2484

Publication Date

9-1-2020

DOI

10.1002/ar.24411

PubMed ID

32365267

Keywords

dental endowment, development, expensive tissues, fetal tissue, folivores, life history, maternal energy, mineralization

Department

Department of Biological Sciences

Share

COinS