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--></style><title>The rise of the Rockies "prepared" our
mammals for ...</title></head><body>
<div><font face="Times">BROWN UNIVERSITY -- PUBLIC
RELEASE: 3-JUN-2015</font><br>
<font face="Arial"></font></div>
<div><font face="Verdana">IMAGE: THE RISE OF THE ROCKIES EXTENDED
FROM BRITISH COLUMBIA TO NEVADA IN THREE PHASES BETWEEN 56 AND 23
MILLION YEARS AGO. THE RISING MOUNTAINS DRIED OUT THE INTERIOR,
PREPARING MAMMALS...</font></div>
<div><font face="Verdana">CREDIT: COURTESY OF ERONEN ET.
AL.</font><font face="Arial"><br>
</font><font face="Verdana"><br>
PROVIDENCE, R.I. -- Paleontologists have documented how dramatic
shifts in climate have led to dramatic shifts in evolution. One such
event, the Grande Coupure, was a wipeout of many European mammal
species 33.9 million years ago when global temperatures and
precipitation declined sharply. What has been puzzling is that during
the same transition between the Eocene and Oligocene periods, North
American mammals fared much better. A new study explains why: the rise
of the Rocky Mountains, already underway for millions of years, had
predisposed populations to adapt to a cold, dry world.</font><br>
<font face="Arial"></font></div>
<div><font face="Verdana">'Regional tectonically driven surface uplift
resulted in large-scale reorganization of precipitation patterns, and
our data show that the mammalian faunas adapted to these changes,'
write the study authors, including Christine Janis, professor of
ecology and evolutionary biology at Brown University, in the<i><b>
Proceedings of the Royal Society B</b></i>:<i><b> Biological
Sciences</b></i>. 'We suggest that the late Eocene mammalian faunas of
North America were already 'pre-adapted' to the colder and drier
global conditions that followed the EO climatic cooling.'</font></div>
<div><font face="Verdana"><br>
The data in the study led by Jussi Eronen of the Senckenberg Research
Institutes in Germany and the University of Helsinki in Finland, come
from the authors' analysis of the fossil record of the two continents,
combined with previous oxygen isotope data that reveal precipitation
patterns, and tectonic models that show the growth of the Rocky
Mountains. Specifically, the study shows that the rise of the range
spread south in three phases from Canada starting more than 50 million
years ago, down through Idaho, and finally into Nevada by 23 million
years ago.</font><br>
<font face="Arial"></font></div>
<div><font face="Verdana">In the meantime, fossil mammal data show,
precipitation in the interior regions dropped, and major shifts in
mammal populations, such as an almost complete loss of primates, took
place. Estimated rainfall based on plant fossils in Wyoming, for
example, dropped from about 1,200 millimeters a year 56 million years
ago to only 750 millimeters a year about 49 million years
ago.</font><font face="Arial"><br>
</font><font face="Verdana"><br>
But across the region these correlated shifts occurred over tens of
millions of years, leaving a well-adapted mix of mammals behind by the
time of the Grand Coupure 34 million years ago.</font><font
face="Arial"><br>
</font><font face="Verdana"><br>
In Europe, meanwhile, tectonic developments weren't a major factor
driving local climate. When the global climate change happened, that
continent's mammals were evolutionary sitting ducks. Other studies
have already suggested that Europe's mammals were largely overrun and
outcompeted by Asian mammals that were already living in colder and
drier conditions.</font></div>
<div><font face="Verdana"><br>
Eronen said the findings should elevate the importance of
collaboration across disciplines, for instance by integrating
geoscience with paleontology, in the analysis of broad evolutionary
patterns.</font><font face="Arial"><br>
</font><font face="Verdana"><br>
'Our results highlight the importance of regional tectonic and surface
uplift processes on the evolution of mammalian faunas,' they
wrote.</font></div>
<div><font face="Verdana" size="-1" color="#1A1A1A"><br>
###</font><font face="Arial" size="-1" color="#1A1A1A"><br>
</font><font face="Verdana" size="-1" color="#1A1A1A">In addition to
Eronen and Janis, the paper's other authors are C. Page Chamberlain of
Stanford University and Andreas Mulch of the Senckenberg Institutes
and Goethe University in Germany.</font><br>
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<div><font face="Bookman Old Style" color="#000000">"Localized
ecological systems are known to shift abruptly and irreversibly from
one state to another when they are forced across critical thresholds.
Here we review evidence that the global ecosystem as a whole can react
in the same way and is approaching a planetary-scale critical
transition as a result of human influence."<br>
<br>
Barnovsky et al. Approaching a state shift in Earth's biosphere.<i>
Nature.<b> </b></i> Volume 486, Pages:52-58</font></div>
<div><font face="Bookman Old Style" color="#000000">Date published:
(07 June 2012)<br>
doi:10.1038/nature11018<br>
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<div><font face="Times" size="-1" color="#1A1A1A"><b>Seeing the
landscape for the trees: Metrics to guide riparian shade management in
river catchments</b></font><font face="Arial" size="-1"
color="#1A1A1A"><br>
</font><font face="Times" size="-1"
color="#1A1A1A"><<</font><font face="Times" size="-1"
color="#0040C2"><u
>http://onlinelibrary.wiley.com/doi/10.1002/2014WR016802/full</u></font
><font face="Times" size="-1" color="#1A1A1A">>></font><font
face="Arial" size="-1" color="#1A1A1A"><br>
</font><font face="Times" size="-1" color="#1A1A1A">Authors:
Matthew F. Johnson, Robert L. Wilby<br>
First Published: 27 May 2015</font></div>
<div><font face="Times" size="-1" color="#1A1A1A"><br>
<b>KEY POINTS:<br>
</b>* Temperature over long
stretches of river will not be affected by riparian shade<br>
* Midreaches of headwater streams
are most responsive to riparian shade</font></div>
<div><font face="Times" size="-1"
color="#1A1A1A">* To offset a
1°C temperature rise, 1 km of trees is necessary in UK small
streams</font><font face="Arial" size="-1" color="#1A1A1A"><br>
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color="#1A1A1A"
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