[dinosaur] Evolution of crocodilian nesting + keratins in skin appendages of terrestrial vertebrates (free pdfs) .

Ben Creisler <[email protected]> Thu, 12 Dec 2019 23:23:44 -0800
Newsgroups gmane.science.dinosaurs.general
Message-ID <CAMR9O1J4qFY2+e2c1kd96WbkF_wzXotZknRPc3YaimvHhfOv7g@mail.gmail.com>
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Ben [email protected]=0A=0ARecent non-dino papers that may be =
of interest, with free pdfs:=0A=0A=0AFree pdf:=0A=0AChristopher M. Murray, =
Brian I. Crother & J. Sean Doody (2019)=0AThe evolution of crocodilian nest=
ing ecology and behavior.=0AEcology and Evolution (advance online publicati=
on)=0Adoi: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_1=
0.1002_ece3.5859&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI=
&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DYhZkUjmGQX0_ZYKXAFBEVk=
QmguaNo8WBJAQuxfnaOIg&s=3DeV38NkO28QLosw0f5FCita7ceRcyOxHyjjtU22AcMY8&e=3D=
=20=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__onlinelibrary.=
wiley.com_doi_10.1002_ece3.5859&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHh=
pN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DYhZkUjm=
GQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&s=3DZ4Y5RFLn3chOmfkvmTEMLw2DhSH2cOd-8o=
lBwTcHsyc&e=3D=20=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__=
onlinelibrary.wiley.com_doi_10.1002_ece3.5859&d=3DDwIFaQ&c=3DclK7kQUTWtAVEO=
VIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9=
SI&m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&s=3DZ4Y5RFLn3chOmfkvmTEM=
Lw2DhSH2cOd-8olBwTcHsyc&e=3D=20=0A=0AFree pdf:=0Ahttps://urldefense.proofpo=
int.com/v2/url?u=3Dhttps-3A__onlinelibrary.wiley.com_doi_pdf_10.1002_ece3.5=
859&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IF=
aUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQ=
uxfnaOIg&s=3DHqxpakvJRM5JjLr88pV_v96UrnQoo34uC82-MhbnTBs&e=3D=20=0A=0ACroco=
dilians comprise an ancient and successful lineage of archosaurs that=0Arep=
eatedly raises questions on how they survived a mass extinction and=0Aremai=
ned relatively unchanged for ~100 million years. Was their success due=0Ato=
 the change=E2=80=90resistant retention of a specific set of traits over ti=
me=0A(phylogenetic conservatism) or due to flexible, generalist capabilitie=
s=0A(e.g., catholic diets, phenotypic plasticity in behavior), or some=0Aco=
mbination of these? We examined the evolution of reproductive ecology and=
=0Abehavior of crocodilians within a phylogenetic perspective, using 14 tra=
its=0Afor all 24 species to determine whether these traits were phylogeneti=
cally=0Aconstrained versus (ecologically) convergent. Our analysis revealed=
 that=0Athe ancestral crocodilian was a mound nester that exhibited both ne=
st=0Aattendance and defense. Nesting mode exhibited 4=E2=80=935 transformat=
ions from=0Amound to hole nesting, a convergence of which habitat may have =
been a=0Adriving factor. Hole nesters were more likely to nest communally, =
but this=0Aassociation may be biased by scale. Although there were exceptio=
ns, mound=0Anesters typically nested during the wet season and hole nesters=
 during the=0Adry season; this trait was relatively conserved, however. Abo=
ut two=E2=80=90thirds=0Aof species timed their nesting with the wet season,=
 while the other third=0Atimed their hatching with the onset of the wet sea=
son. Nest attendance and=0Adefense were nearly ubiquitous and thus exhibite=
d phylogenetic=0Aconservatism, but attendance lodging was diverse among spe=
cies, showing=0Amultiple reversals between water and burrows. Collectively,=
 our analysis=0Areveals that reproductive trait evolution in crocodilians r=
eflects=0Aphylogenetic constraint (nest attendance, nest defense), ecologic=
al=0Aconvergence (seasonal timing of nesting, nest attendance lodging), or =
both=0A(mode of nesting). Some traits (e.g., communal nesting and mode of n=
esting)=0Awere autocorrelated. Our analysis provides a framework for addres=
sing=0Ahypotheses raised for why there has been trait convergence in reprod=
uctive=0Aecology and behavior in crocodilians and why some traits remained=
=0Aphylogenetically conserved.=0A=0A=0A=3D=3D=3D=0A=0AFree pdf:=0A=0AFloria=
n Ehrlich, Julia Lachner, Marcela Hermann, Erwin Tschachler & Leopold=0AEck=
hart (2019)=0AConvergent evolution of cysteine-rich keratins in hard skin a=
ppendages of=0Aterrestrial vertebrates.=0AMolecular Biology and Evolution, =
msz279,=0Adoi: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.o=
rg_10.1093_molbev_msz279&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7=
CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DYhZkUjmGQX0_ZY=
KXAFBEVkQmguaNo8WBJAQuxfnaOIg&s=3DzQw-Yii3H5klENiXQaX20S7c11CCQikdHMRaTX__R=
Bc&e=3D=20=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__academi=
c.oup.com_mbe_advance-2Darticle_doi_10.1093_molbev_msz279_5652086&d=3DDwIFa=
Q&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZ=
gecRCKHn5g4z1CYJgFW9SI&m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&s=3D=
HunNReCsmYMAoWf7UYYwoeecC-lQ6xqLhQiWHAtp7Z0&e=3D=20=0A=0A=0ATerrestrial ver=
tebrates have evolved hard skin appendages, such as scales,=0Aclaws, feathe=
rs and hair that play crucial roles in defense, predation,=0Alocomotion, an=
d thermal insulation. The mechanical properties of these skin=0Aappendages =
are largely determined by cornified epithelial components.=0ASo-called "hai=
r keratins", cysteine-rich intermediate filament proteins=0Athat undergo co=
valent cross-linking via disulfide bonds, are the crucial=0Astructural prot=
eins of hair and claws in mammals and hair keratin orthologs=0Aare also pre=
sent in lizard claws, indicating an evolutionary origin in a=0Ahairless com=
mon ancestor of amniotes. Here, we show that reptiles and birds=0Ahave also=
 other cysteine-rich keratins which lack cysteine-rich orthologs=0Ain mamma=
ls. In addition to hard acidic (type I) sauropsid-specific (HAS)=0Akeratins=
, we identified hard basic (type II) sauropsid-specific (HBS)=0Akeratins wh=
ich are conserved in lepidosaurs, turtles, crocodilians and=0Abirds. Immuno=
histochemical analysis with a newly made antibody revealed=0Aexpression of =
chicken HBS1 keratin in the cornifying epithelial cells of=0Afeathers. Mole=
cular phylogenetics suggested that the high cysteine contents=0Aof HAS and =
HBS keratins evolved independently from the cysteine-rich=0Asequences of ha=
ir keratin orthologs, thus representing products of=0Aconvergent evolution.=
 In conclusion, we propose an evolutionary model in=0Awhich HAS and HBS ker=
atins evolved as structural proteins in epithelial=0Acornification of repti=
les and at least one HBS keratin was co-opted as a=0Acomponent of feathers =
after the evolutionary divergence of birds from=0Areptiles. Thus, cytoskele=
tal proteins of hair and feathers are products of=0Aconvergent evolution an=
d evolutionary co-option to similar biomechanical=0Afunctions in clade-spec=
ific hard skin appendages.=0A=

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<div dir=3D"ltr"><div><br></div>Ben Creisler<div><a href=3D"mailto:bcreisle=
[email protected]">[email protected]</a></div><div><br></div><div>Recent non-di=
no papers that may be of interest, with free pdfs:<br><div><div><br></div><=
div><br></div><div>Free pdf:</div><div><br>Christopher M. Murray, Brian I. =
Crother &amp; J. Sean Doody (2019)<br>The evolution of crocodilian nesting =
ecology and behavior.<br>Ecology and Evolution (advance online publication)=
<br>doi: <a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__=
doi.org_10.1002_ece3.5859&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOU=
HhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=
=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&amp;s=3DeV38NkO28QLosw0f5FCi=
ta7ceRcyOxHyjjtU22AcMY8&amp;e=3D">https://doi.org/10.1002/ece3.5859</a><br>=
<a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__onlinelib=
rary.wiley.com_doi_10.1002_ece3.5859&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOV=
Igvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJg=
FW9SI&amp;m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&amp;s=3DZ4Y5RFLn3=
chOmfkvmTEMLw2DhSH2cOd-8olBwTcHsyc&amp;e=3D">https://onlinelibrary.wiley.co=
m/doi/10.1002/ece3.5859</a><br><a href=3D"https://urldefense.proofpoint.com=
/v2/url?u=3Dhttps-3A__onlinelibrary.wiley.com_doi_10.1002_ece3.5859&amp;d=
=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO=
4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaN=
o8WBJAQuxfnaOIg&amp;s=3DZ4Y5RFLn3chOmfkvmTEMLw2DhSH2cOd-8olBwTcHsyc&amp;e=
=3D">https://onlinelibrary.wiley.com/doi/10.1002/ece3.5859</a><br><br>Free =
pdf:<br><a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__o=
nlinelibrary.wiley.com_doi_pdf_10.1002_ece3.5859&amp;d=3DDwMFaQ&amp;c=3DclK=
7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRC=
KHn5g4z1CYJgFW9SI&amp;m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&amp;s=
=3DHqxpakvJRM5JjLr88pV_v96UrnQoo34uC82-MhbnTBs&amp;e=3D">https://onlinelibr=
ary.wiley.com/doi/pdf/10.1002/ece3.5859</a><br><br>Crocodilians comprise an=
 ancient and successful lineage of archosaurs that repeatedly raises questi=
ons on how they survived a mass extinction and remained relatively unchange=
d for ~100 million years. Was their success due to the change=E2=80=90resis=
tant retention of a specific set of traits over time (phylogenetic conserva=
tism) or due to flexible, generalist capabilities (e.g., catholic diets, ph=
enotypic plasticity in behavior), or some combination of these? We examined=
 the evolution of reproductive ecology and behavior of crocodilians within =
a phylogenetic perspective, using 14 traits for all 24 species to determine=
 whether these traits were phylogenetically constrained versus (ecologicall=
y) convergent. Our analysis revealed that the ancestral crocodilian was a m=
ound nester that exhibited both nest attendance and defense. Nesting mode e=
xhibited 4=E2=80=935 transformations from mound to hole nesting, a converge=
nce of which habitat may have been a driving factor. Hole nesters were more=
 likely to nest communally, but this association may be biased by scale. Al=
though there were exceptions, mound nesters typically nested during the wet=
 season and hole nesters during the dry season; this trait was relatively c=
onserved, however. About two=E2=80=90thirds of species timed their nesting =
with the wet season, while the other third timed their hatching with the on=
set of the wet season. Nest attendance and defense were nearly ubiquitous a=
nd thus exhibited phylogenetic conservatism, but attendance lodging was div=
erse among species, showing multiple reversals between water and burrows. C=
ollectively, our analysis reveals that reproductive trait evolution in croc=
odilians reflects phylogenetic constraint (nest attendance, nest defense), =
ecological convergence (seasonal timing of nesting, nest attendance lodging=
), or both (mode of nesting). Some traits (e.g., communal nesting and mode =
of nesting) were autocorrelated. Our analysis provides a framework for addr=
essing hypotheses raised for why there has been trait convergence in reprod=
uctive ecology and behavior in crocodilians and why some traits remained ph=
ylogenetically conserved.<br><br><br>=3D=3D=3D</div><div><br></div><div>Fre=
e pdf:<br><br>Florian Ehrlich, Julia Lachner, Marcela Hermann, Erwin Tschac=
hler &amp; Leopold Eckhart (2019)<br>Convergent evolution of cysteine-rich =
keratins in hard skin appendages of terrestrial vertebrates.<br>Molecular B=
iology and Evolution, msz279, <br>doi: <a href=3D"https://urldefense.proofp=
oint.com/v2/url?u=3Dhttps-3A__doi.org_10.1093_molbev_msz279&amp;d=3DDwMFaQ&=
amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_=
Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxf=
naOIg&amp;s=3DzQw-Yii3H5klENiXQaX20S7c11CCQikdHMRaTX__RBc&amp;e=3D">https:/=
/doi.org/10.1093/molbev/msz279</a><br><a href=3D"https://urldefense.proofpo=
int.com/v2/url?u=3Dhttps-3A__academic.oup.com_mbe_advance-2Darticle_doi_10.=
1093_molbev_msz279_5652086&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BO=
UHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;=
m=3DYhZkUjmGQX0_ZYKXAFBEVkQmguaNo8WBJAQuxfnaOIg&amp;s=3DHunNReCsmYMAoWf7UYY=
woeecC-lQ6xqLhQiWHAtp7Z0&amp;e=3D">https://academic.oup.com/mbe/advance-art=
icle/doi/10.1093/molbev/msz279/5652086</a></div><div><br><br>Terrestrial ve=
rtebrates have evolved hard skin appendages, such as scales, claws, feather=
s and hair that play crucial roles in defense, predation, locomotion, and t=
hermal insulation. The mechanical properties of these skin appendages are l=
argely determined by cornified epithelial components. So-called &quot;hair =
keratins&quot;, cysteine-rich intermediate filament proteins that undergo c=
ovalent cross-linking via disulfide bonds, are the crucial structural prote=
ins of hair and claws in mammals and hair keratin orthologs are also presen=
t in lizard claws, indicating an evolutionary origin in a hairless common a=
ncestor of amniotes. Here, we show that reptiles and birds have also other =
cysteine-rich keratins which lack cysteine-rich orthologs in mammals. In ad=
dition to hard acidic (type I) sauropsid-specific (HAS) keratins, we identi=
fied hard basic (type II) sauropsid-specific (HBS) keratins which are conse=
rved in lepidosaurs, turtles, crocodilians and birds. Immunohistochemical a=
nalysis with a newly made antibody revealed expression of chicken HBS1 kera=
tin in the cornifying epithelial cells of feathers. Molecular phylogenetics=
 suggested that the high cysteine contents of HAS and HBS keratins evolved =
independently from the cysteine-rich sequences of hair keratin orthologs, t=
hus representing products of convergent evolution. In conclusion, we propos=
e an evolutionary model in which HAS and HBS keratins evolved as structural=
 proteins in epithelial cornification of reptiles and at least one HBS kera=
tin was co-opted as a component of feathers after the evolutionary divergen=
ce of birds from reptiles. Thus, cytoskeletal proteins of hair and feathers=
 are products of convergent evolution and evolutionary co-option to similar=
 biomechanical functions in clade-specific hard skin appendages.<br><br><br=
></div><div><br></div></div></div></div>=0A=

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