Skip to main content
Log in

Was endothermy in amniotes induced by an early stop in growth during ontogeny?

  • Concepts and Synthesis
  • Published:
The Science of Nature Aims and scope Submit manuscript

Abstract

Endothermy and its evolution are still an unresolved issue. Here, we present a model which transforms an ectothermic amniote (ancestor) into a derived amniote (descendant) showing many characteristics seen in extant endothermic birds and mammals. Consistent with the fossil record within the ancestral lineages of birds and mammals, the model assumes that mutations in genes which get active during ontogeny and affect body growth resulted in a reduced asymptotic body size and an early growth stop of the descendant. We show that such a postulated early growth stop in the descendant simultaneously increases the growth rate and metabolic rate, and also changes six life history traits (offspring mass, annual clutch/litter mass, number of offspring per year, age and mass at which sexual maturity is reached, age at which the individual is fully grown) of the descendant compared to a similar-sized ancestor. All these changes coincide with known differences between recent ectothermic and endothermic amniotes. We also elaborate many other differences and similarities in biological characteristics supporting the early growth stop. An early stop in growth during ontogeny thus could have played a key role in the evolution of endothermy within the reptilia and therapsids. It generated variability in characteristics of ancestral ectotherms, which was subject to natural selection in the past and resulted in many adaptations linked to endothermy in today’s birds and mammals.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

Download references

Acknowledgements

This work was not possible without earlier work of many other researchers dealing with metabolism, endothermy, evolution or growth. JW thanks Alfred Seitz (†) for his open mind, Martin Sander for arousing JWs interest in dinosaur metabolism and EMG for her good coaching and fruitful discussions. JW developed the model, designed and conducted the analyses and wrote the manuscript. EMG helped in discussion, focusing ideas and worked on the manuscript text. JW was partially financed by the German Research Foundation (grant GR 2625/2-2) and by the Johannes Gutenberg University of Mainz Centre for Computational Sciences (SRFN).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jan Werner.

Additional information

Communicated by: Sven Thatje

Electronic supplementary material

ESM 1

(DOCX 419 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Werner, J., Griebeler, E.M. Was endothermy in amniotes induced by an early stop in growth during ontogeny?. Sci Nat 104, 90 (2017). https://doi.org/10.1007/s00114-017-1513-1

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00114-017-1513-1

Keywords

Navigation