Version 1
: Received: 29 November 2019 / Approved: 30 November 2019 / Online: 30 November 2019 (09:59:13 CET)
Version 2
: Received: 18 July 2020 / Approved: 20 July 2020 / Online: 20 July 2020 (10:31:23 CEST)
How to cite:
Rial, R.V.; Canellas, F.; Gamundi, A.; Akaârir, M.; Nicollau, M.C.; Martí-Reina, A.; Rubiño, J.A.; Barceló, P. How The Mammalian Sleep Was Born. Preprints2019, 2019110387. https://doi.org/10.20944/preprints201911.0387.v2
Rial, R.V.; Canellas, F.; Gamundi, A.; Akaârir, M.; Nicollau, M.C.; Martí-Reina, A.; Rubiño, J.A.; Barceló, P. How The Mammalian Sleep Was Born. Preprints 2019, 2019110387. https://doi.org/10.20944/preprints201911.0387.v2
Rial, R.V.; Canellas, F.; Gamundi, A.; Akaârir, M.; Nicollau, M.C.; Martí-Reina, A.; Rubiño, J.A.; Barceló, P. How The Mammalian Sleep Was Born. Preprints2019, 2019110387. https://doi.org/10.20944/preprints201911.0387.v2
APA Style
Rial, R.V., Canellas, F., Gamundi, A., Akaârir, M., Nicollau, M.C., Martí-Reina, A., Rubiño, J.A., & Barceló, P. (2020). How The Mammalian Sleep Was Born. Preprints. https://doi.org/10.20944/preprints201911.0387.v2
Chicago/Turabian Style
Rial, R.V., José A. Rubiño and Pere Barceló. 2020 "How The Mammalian Sleep Was Born" Preprints. https://doi.org/10.20944/preprints201911.0387.v2
Abstract
The Nocturnal Bottleneck explains how mammals evolved from their reptilian ancestors after inverting the chronotype, form diurnal to nocturnal. Pre-mammals traded-off the excellent visual system of their ancestors for improvements in audition and in olfactory telencephalon, needed for efficient orientation in the dark. This was how the mammalian nocturnal telencephalic wakefulness was born. However, the modified visual system of those pre-mammals became sensitive to the dangerous diurnal light and the exposure would involve a high risk of blindness and death. Therefore, pre-mammals had to remain immobile with closed eyes hidden in lightproof burrows during light time. This was the birth of the mammalian sleep. Typical reptiles distribute their wake time cycling between Basking Behavior, to attain the preferred body temperature, and poikilothermic Goal Directed Behavior, to perform life sustaining tasks. These cycles persisted during the new mammalian sleep. However, as the behavioral output had to be blocked during light time, the paralyzed reptilian Basking Behavior and Goal Directed Behavior cycles became the NREM and REM cycles, respectively. This was how NREM and REM cycles remained incorporated within the mammalian sleep. After the Cretaceous-Paleogene extinction, the environmental pressure for nocturnal life was softened, allowing high variability in chronotype and sleeping patterns. This permitted some mammalian groups, e.g., primates, to begin the quest for diurnal wake.Concluding, sleep constituted an additional bottleneck in the mammalian evolution. The reduced population of pre-mammals that was able to develop sleep during light time, including NREM and REM, became full mammals and survived; the remainder perished.
Keywords
evolutionary bottleneck; evolution of sleep; sleep variability; function of sleep
Subject
Social Sciences, Behavior Sciences
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Commenter: Rubén Víctor Rial
Commenter's Conflict of Interests: Author