[dinosaur] Shrinking dinosaurs and evolution of endothermy in birds (free pdf)

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Ben [email protected]=0D=0A=0D=0AA new paper in open access=
:=0D=0A=0D=0AEnrico L. Rezende, Leonardo D. Bacigalupe, Roberto F. Nespolo =
and Francisco=0D=0ABozinovic (2020)=0D=0AShrinking dinosaurs and the evolut=
ion of endothermy in birds.=0D=0AScience Advances  6(1): eaaw4486=0D=0ADOI:=
 10.1126/sciadv.aaw4486=0D=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dh=
ttps-3A__advances.sciencemag.org_content_6_1_eaaw4486&d=3DDwIBaQ&c=3DclK7kQ=
UTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z=
1CYJgFW9SI&m=3Dabir3ijt2mXT4zhuMtfzK_3ci2h2lgPSk7MnH9793TE&s=3DO4pka6fy02Eb=
Q5VEnfu8u9adaCdeXC_mUXfgY6HbGgA&e=3D =0D=0A=0D=0AFree pdf:=0D=0Ahttps://url=
defense.proofpoint.com/v2/url?u=3Dhttps-3A__advances.sciencemag.org_content=
_6_1_eaaw4486_tab-2Dpdf&d=3DDwIBaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7C=
Sfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3Dabir3ijt2mXT4zh=
uMtfzK_3ci2h2lgPSk7MnH9793TE&s=3DQYoOl-RHAub4wQ99uCfbr9662IMGdra7i8YckLmtf-=
U&e=3D =0D=0A=0D=0A=0D=0AThe evolution of endothermy represents a major tra=
nsition in vertebrate=0D=0Ahistory, yet how and why endothermy evolved in b=
irds and mammals remains=0D=0Acontroversial. Here, we combine a heat transf=
er model with theropod body=0D=0Asize data to reconstruct the evolution of =
metabolic rates along the bird=0D=0Astem lineage. Results suggest that a re=
duction in size constitutes the path=0D=0Aof least resistance for endotherm=
y to evolve, maximizing thermal niche=0D=0Aexpansion while obviating the co=
sts of elevated energy requirements. In=0D=0Athis scenario, metabolism woul=
d have increased with the miniaturization=0D=0Aobserved in the Early-Middle=
 Jurassic (~180 to 170 million years ago),=0D=0Aresulting in a gradient of =
metabolic levels in the theropod phylogeny.=0D=0AWhereas basal theropods wo=
uld exhibit lower metabolic rates, more recent=0D=0Anonavian lineages were =
likely decent thermoregulators with elevated=0D=0Ametabolism. These analyse=
s provide a tentative temporal sequence of the key=0D=0Aevolutionary transi=
tions that resulted in the emergence of small,=0D=0Aendothermic, feathered =
flying dinosaurs.=0D=0A=0D=0A=0D=0ANews:=0D=0A=0D=0Ahttps://urldefense.proo=
fpoint.com/v2/url?u=3Dhttps-3A__home.bt.com_news_science-2Dnews_shrinking-2=
Ddinosaurs-2Dallowed-2Dbirds-2Dto-2Devolve-2Das-2Dwarm-2Dblooded-2Dcreature=
s-2Dstudy-2D11364422110438&d=3DDwIBaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8=
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PXsk&e=3D =0D=0A=

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<div dir=3D"ltr"><br><div>Ben Creisler</div><div><a href=3D"mailto:bcreisle=
[email protected]">[email protected]</a></div><div><br></div><div>A new paper i=
n open access:</div><div><br></div><div>Enrico L. Rezende, Leonardo D. Baci=
galupe, Roberto F. Nespolo and Francisco Bozinovic (2020)<br>Shrinking dino=
saurs and the evolution of endothermy in birds.<br>Science Advances =C2=A06=
(1): eaaw4486<br>DOI: 10.1126/sciadv.aaw4486<br><a href=3D"https://urldefen=
se.proofpoint.com/v2/url?u=3Dhttps-3A__advances.sciencemag.org_content_6_1_=
eaaw4486&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI=
&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3Dabir3ijt2mXT4z=
huMtfzK_3ci2h2lgPSk7MnH9793TE&amp;s=3DO4pka6fy02EbQ5VEnfu8u9adaCdeXC_mUXfgY=
6HbGgA&amp;e=3D">https://advances.sciencemag.org/content/6/1/eaaw4486</a><b=
r><br>Free pdf:<br><a href=3D"https://urldefense.proofpoint.com/v2/url?u=3D=
https-3A__advances.sciencemag.org_content_6_1_eaaw4486_tab-2Dpdf&amp;d=3DDw=
MFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaU=
mGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3Dabir3ijt2mXT4zhuMtfzK_3ci2h2lgPSk=
7MnH9793TE&amp;s=3DQYoOl-RHAub4wQ99uCfbr9662IMGdra7i8YckLmtf-U&amp;e=3D">ht=
tps://advances.sciencemag.org/content/6/1/eaaw4486/tab-pdf</a></div><div><b=
r></div><div><br>The evolution of endothermy represents a major transition =
in vertebrate history, yet how and why endothermy evolved in birds and mamm=
als remains controversial. Here, we combine a heat transfer model with ther=
opod body size data to reconstruct the evolution of metabolic rates along t=
he bird stem lineage. Results suggest that a reduction in size constitutes =
the path of least resistance for endothermy to evolve, maximizing thermal n=
iche expansion while obviating the costs of elevated energy requirements. I=
n this scenario, metabolism would have increased with the miniaturization o=
bserved in the Early-Middle Jurassic (~180 to 170 million years ago), resul=
ting in a gradient of metabolic levels in the theropod phylogeny. Whereas b=
asal theropods would exhibit lower metabolic rates, more recent nonavian li=
neages were likely decent thermoregulators with elevated metabolism. These =
analyses provide a tentative temporal sequence of the key evolutionary tran=
sitions that resulted in the emergence of small, endothermic, feathered fly=
ing dinosaurs.<br><br><br>News:<br><br><a href=3D"https://urldefense.proofp=
oint.com/v2/url?u=3Dhttps-3A__home.bt.com_news_science-2Dnews_shrinking-2Dd=
inosaurs-2Dallowed-2Dbirds-2Dto-2Devolve-2Das-2Dwarm-2Dblooded-2Dcreatures-=
2Dstudy-2D11364422110438&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUH=
hpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=
=3Dabir3ijt2mXT4zhuMtfzK_3ci2h2lgPSk7MnH9793TE&amp;s=3DkxL5O5jUGM26HfgFLc0y=
3Gf8d5k8MRvunZiV1WdPXsk&amp;e=3D">https://home.bt.com/news/science-news/shr=
inking-dinosaurs-allowed-birds-to-evolve-as-warm-blooded-creatures-study-11=
364422110438</a><br><br></div></div>=0A=

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