Abstract

Growth rates importantly determine developmental time and are, therefore, a key variable of a species' life history. A widely used method to reconstruct growth rates and to estimate age at death in extant and particularly in fossil vertebrates is the analysis of bone tissue apposition rates. Lines of arrested growth (LAGs) are of special interest here, as they indicate a halt in bone growth. However, although of great importance, the time intervals between, and particularly the reason of growth arrests remains unknown. Therefore, experiments are increasingly called for to calibrate growth rates with tissue types and life history events, and to provide reliable measurements of the time involved in the formation of LAGs. Based on in vivo bone labelling, we calibrated periods of bone tissue apposition, growth arrest, drift and resorption over the period from birth to post-weaning in a large mammal, the red deer. We found that bone growth rates tightly matched the daily weight gain curve, i.e. decreased with age, with two discrete periods of growth rate disruption that coincided with the life history events birth and weaning, that were visually recognisable in bone tissue as either partial LAGs or annuli. Our study identified for the first time in a large mammal a general pattern for juvenile bone growth rates, including periods of growth arrest. The tight correlation between daily weight gain and bone tissue apposition suggests that the red deer bone growth model is valid for ruminants in general where the daily weight gain curve is comparable.

Highlights

  • Growth rates importantly determine developmental time and are, a key variable of a species’ life history

  • We describe how birth and weaning events affect growth in general and bone growth in particular, give and account of the growth marks these events leave in all limb bones, and settle the time of onset and duration of the impact of these early life history events on bone tissue growth rate

  • The quantitative analysis revealed the complete record of growth rate of the six limb bones analysed for hand raised (C2) red deer calves and those nursed by their mother (C1) over the first 6 months of life (Fig. 2a)

Read more

Summary

Introduction

Growth rates importantly determine developmental time and are, a key variable of a species’ life history. We used in vivo labelling to analyse the impact of life history events on bone tissue formation and to reconstruct early growth rate in a long lived mammal, the red deer.

Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call