夜行瓶頸

夜行瓶頸假說（英文：Nocturnal Bottleneck Hypothesis）是演化生物學上首先由美國視光學家戈登·林恩·沃爾斯（英語：Gordon Lynn Walls）於1942年提出的一個假說，用於解釋許多哺乳動物的特徵行為。

夜行瓶頸假說認為，哺乳動物在由恐龍和翼龍稱霸的中生代演化史上大多屬於夜行性動物^[1]，依靠錯位競爭躲避這些優勢動物的捕食。雖然部分哺乳動物（主要是胎盤類和有袋類）在6600萬年前的白堊紀﹣古近紀滅絕事件之後填補了非鳥恐龍和翼龍滅絕後空出的生態位並演化成了日行性動物，然而歷時一億六千萬年的夜行生活在解剖學特徵上留下了許多適合夜行性的演化特徵，而許多的哺乳動物如今依然仍然為夜行性^[2]。

哺乳動物的演化

哺乳動物演化自犬齒獸亞目，一群外型似犬的合弓綱物種，崛起於二疊紀－三疊紀滅絕事件後。然而，同樣崛起於三疊紀的主龍類，如恐龍和鱷魚，導致了大型犬齒獸亞目物種的滅絕，僅剩下體型偏小的物種^[3]。這些體型較小的犬齒獸亞目物種最終僅能去填補那些不用過於和日行性恐龍競爭的生態位，逐漸演化成以昆蟲為食的夜行性動物^[4]。縱使許多現存的演化支於中生代時就已經逐漸分化，然而這些早期的哺乳動物依然維持了小體型及夜行性。

白堊紀晚期的滅絕事件讓哺乳動物得以去填補恐龍留下的生態位，然而在那之後的數百萬年，哺乳動物依舊保持嬌小的體型^[5]。雖然現今的大型動物幾乎均為哺乳動物，但大多哺乳動物直到現今依然保持夜行性^[6]。

哺乳動物針對夜行性的適應

有些哺乳動物的特徵是針對於夜行性生活的適應，包括：

感官

靈敏的聽覺適應，包括耳廓與聽小骨
敏銳的嗅覺、完整發展的鼻甲
敏感的觸覺，具有感覺毛^[7]
除了高等靈長類外，具有非常大的角膜，比起鳥類和爬蟲類具有較差的成像能力^[8]
有限的彩色視覺^[9]

生理學

特別的棕色脂肪組織，能快速產生體熱^[10]
線粒體進行呼吸作用的速率為同等或體型較小的爬蟲類的5-7倍^[11]
毛髮能協助在寒冷環境或夜晚時維持體溫調節
缺乏防範白天紫外線的機制^[12]
胎盤動物缺乏需要可見光協助活化的光裂合酶，此種酶可於細菌、真菌甚至是大部分其他動物身上發現^[13]^[14]

行為

所有基群（至少於胎盤動物）的晝夜節律與行為模式皆為夜行性^[15]^[16]
行穴居（英語：Burrow）生活以躲避惡劣天氣與日行性掠食者為基群哺乳動物的特徵^[17]。

參考文獻

^ Gerkema MP, Davies WI, Foster RG, Menaker M, Hut RA. The nocturnal bottleneck and the evolution of activity patterns in mammals. Proc Biol Sci. 2013 Jul 3;280(1765):20130508. doi: 10.1098/rspb.2013.0508
^ Sinn, J. New Study Shows Effects of Prehistoric Nocturnal Life on Mammalian Vision. University of Texas. [24 November 2014]. （原始內容存檔於2019-09-05）.
^ Benton, Michael J. Vertebrate palaeontology 3rd. Oxford: Blackwell Science. 2004. ISBN 978-0-632-05637-8.
^ Kielan-Jaworowska, Zofia; Cifelli, Richard L.; Luo, Zhe-Xi. Mammals from the age of dinosaurs : origins, evolution, and structure. New York: Columbia University Press. 2004: 5. ISBN 978-0-231-11918-4.
^ Than, K. Rise of Modern Mammals Occurred Long After Dinosaur Demise. LiveScience. [24 November 2014]. （原始內容存檔於2020-05-09）.
^ Gamberale-Stille, G.; Hall, K. S. S.; Tullberg, B. S. Signals of profitability? Food colour preferences in migrating juvenile blackcaps differ for fruits and insects. Evolutionary Ecology. 10 August 2006, 20 (5): 479–490. doi:10.1007/s10682-006-0015-y.
^ Grant, Robyn; Mitchinson, Ben; Prescott, Tony. Vibrissal behaviour and function. Scholarpedia. 2011, 6 (10): 6642 [October 29, 2011]. Bibcode:2011SchpJ...6.6642P. doi:10.4249/scholarpedia.6642. （原始內容存檔於2021-01-15）.
^ Hall, M. I.; Kamilar, J. M.; Kirk, E. C. Eye shape and the nocturnal bottleneck of mammals. Proceedings of the Royal Society B: Biological Sciences. 24 October 2012, 279 (1749): 4962–4968. PMC 3497252 . PMID 23097513. doi:10.1098/rspb.2012.2258.
^ Davies, Wayne I. L.; Collin, Shaun P.; Hunt, David M. Molecular ecology and adaptation of visual photopigments in craniates. Molecular Ecology. July 2012, 21 (13): 3121–3158. PMID 22650357. doi:10.1111/j.1365-294X.2012.05617.x.
^ Cannon, B. Brown Adipose Tissue: Function and Physiological Significance. Physiological Reviews. 1 January 2004, 84 (1): 277–359. PMID 14715917. doi:10.1152/physrev.00015.2003.
^ Brand, M. D.; Couture, P.; Else, P. L.; Withers, K. W.; Hulbert, A. J. Evolution of energy metabolism. Proton permeability of the inner membrane of liver mitochondria is greater in a mammal than in a reptile.. The Biochemical Journal. 1 April 1991, 275 (1): 81–6. PMC 1150016 . PMID 1850242. doi:10.1042/bj2750081.
^ Ringvold, Amund. Aqueous humour and ultraviolet radiation. Acta Ophthalmologica. 27 May 2009, 58 (1): 69–82. PMID 6773294. doi:10.1111/j.1755-3768.1980.tb04567.x.
^ Lucas-Lledó JI, Lynch M. Evolution of mutation rates: phylogenomic analysis of the photolyase/cryptochrome family. Molecular Biology and Evolution. May 2009, 26 (5): 1143–53. PMC 2668831 . PMID 19228922. doi:10.1093/molbev/msp029.
^ Clues from a Somalian cavefish about modern mammals' dark past. Science Daily (Cell Press). October 11, 2018 [11 October 2018]. （原始內容存檔於2020-11-09）.
^ Gerkema, M. P.; Davies, W. I. L.; Foster, R. G.; Menaker, M.; Hut, R. A. The nocturnal bottleneck and the evolution of activity patterns in mammals. Proceedings of the Royal Society B: Biological Sciences. 3 July 2013, 280 (1765): 20130508. PMC 3712437 . PMID 23825205. doi:10.1098/rspb.2013.0508.
^ Menaker, M.; Moreira, L.F.; Tosini, G. Evolution of circadian organization in vertebrates. Brazilian Journal of Medical and Biological Research. March 1997, 30 (3): 305–313. PMID 9246228. doi:10.1590/S0100-879X1997000300003.
^ Damiani, R.; Modesto, S.; Yates, A.; Neveling, J. Earliest evidence of cynodont burrowing. Proceedings of the Royal Society B: Biological Sciences. 22 August 2003, 270 (1525): 1747–51. PMC 1691433 . PMID 12965004. doi:10.1098/rspb.2003.2427.

[1] Gerkema MP, Davies WI, Foster RG, Menaker M, Hut RA. The nocturnal bottleneck and the evolution of activity patterns in mammals. Proc Biol Sci. 2013 Jul 3;280(1765):20130508. doi: 10.1098/rspb.2013.0508

[2] Sinn, J. New Study Shows Effects of Prehistoric Nocturnal Life on Mammalian Vision. University of Texas. [24 November 2014]. （原始內容存檔於2019-09-05）.

[3] Benton, Michael J. Vertebrate palaeontology 3rd. Oxford: Blackwell Science. 2004. ISBN 978-0-632-05637-8.

[4] Kielan-Jaworowska, Zofia; Cifelli, Richard L.; Luo, Zhe-Xi. Mammals from the age of dinosaurs : origins, evolution, and structure. New York: Columbia University Press. 2004: 5. ISBN 978-0-231-11918-4.

[5] Than, K. Rise of Modern Mammals Occurred Long After Dinosaur Demise. LiveScience. [24 November 2014]. （原始內容存檔於2020-05-09）.

[6] Gamberale-Stille, G.; Hall, K. S. S.; Tullberg, B. S. Signals of profitability? Food colour preferences in migrating juvenile blackcaps differ for fruits and insects. Evolutionary Ecology. 10 August 2006, 20 (5): 479–490. doi:10.1007/s10682-006-0015-y.

[scholarpedia-7] Grant, Robyn; Mitchinson, Ben; Prescott, Tony. Vibrissal behaviour and function. Scholarpedia. 2011, 6 (10): 6642 [October 29, 2011]. Bibcode:2011SchpJ...6.6642P. doi:10.4249/scholarpedia.6642. （原始內容存檔於2021-01-15）.

[8] Hall, M. I.; Kamilar, J. M.; Kirk, E. C. Eye shape and the nocturnal bottleneck of mammals. Proceedings of the Royal Society B: Biological Sciences. 24 October 2012, 279 (1749): 4962–4968. PMC 3497252 . PMID 23097513. doi:10.1098/rspb.2012.2258.

[9] Davies, Wayne I. L.; Collin, Shaun P.; Hunt, David M. Molecular ecology and adaptation of visual photopigments in craniates. Molecular Ecology. July 2012, 21 (13): 3121–3158. PMID 22650357. doi:10.1111/j.1365-294X.2012.05617.x.

[10] Cannon, B. Brown Adipose Tissue: Function and Physiological Significance. Physiological Reviews. 1 January 2004, 84 (1): 277–359. PMID 14715917. doi:10.1152/physrev.00015.2003.

[11] Brand, M. D.; Couture, P.; Else, P. L.; Withers, K. W.; Hulbert, A. J. Evolution of energy metabolism. Proton permeability of the inner membrane of liver mitochondria is greater in a mammal than in a reptile.. The Biochemical Journal. 1 April 1991, 275 (1): 81–6. PMC 1150016 . PMID 1850242. doi:10.1042/bj2750081.

[12] Ringvold, Amund. Aqueous humour and ultraviolet radiation. Acta Ophthalmologica. 27 May 2009, 58 (1): 69–82. PMID 6773294. doi:10.1111/j.1755-3768.1980.tb04567.x.

[13] Lucas-Lledó JI, Lynch M. Evolution of mutation rates: phylogenomic analysis of the photolyase/cryptochrome family. Molecular Biology and Evolution. May 2009, 26 (5): 1143–53. PMC 2668831 . PMID 19228922. doi:10.1093/molbev/msp029.

[14] Clues from a Somalian cavefish about modern mammals' dark past. Science Daily (Cell Press). October 11, 2018 [11 October 2018]. （原始內容存檔於2020-11-09）.

[15] Gerkema, M. P.; Davies, W. I. L.; Foster, R. G.; Menaker, M.; Hut, R. A. The nocturnal bottleneck and the evolution of activity patterns in mammals. Proceedings of the Royal Society B: Biological Sciences. 3 July 2013, 280 (1765): 20130508. PMC 3712437 . PMID 23825205. doi:10.1098/rspb.2013.0508.

[16] Menaker, M.; Moreira, L.F.; Tosini, G. Evolution of circadian organization in vertebrates. Brazilian Journal of Medical and Biological Research. March 1997, 30 (3): 305–313. PMID 9246228. doi:10.1590/S0100-879X1997000300003.

[17] Damiani, R.; Modesto, S.; Yates, A.; Neveling, J. Earliest evidence of cynodont burrowing. Proceedings of the Royal Society B: Biological Sciences. 22 August 2003, 270 (1525): 1747–51. PMC 1691433 . PMID 12965004. doi:10.1098/rspb.2003.2427.

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