Global warming led to dwarfism in mammals—twice

Nov 02, 2013

Mammal body size decreased significantly during at least two ancient global warming events, a new finding that suggests a similar outcome is possible in response to human-caused climate change, according to a University of Michigan paleontologist and his colleagues.

Researchers have known for years that mammals such as primates and the groups that include horses and deer became much smaller during a period of warming, called the Paleocene-Eocene Thermal Maximum (PETM), about 55 million years ago.

Now U-M paleontologist Philip Gingerich and his colleagues have found evidence that mammalian "dwarfing" also occurred during a separate, smaller event that occurred about 2 million years after the PETM, around 53 million years ago.

"The fact that it happened twice significantly increases our confidence that we're seeing cause and effect, that one interesting response to global warming in the past was a substantial decrease in in mammalian species," said Gingerich, a professor of earth and environmental sciences.

The research team also includes scientists from the University of New Hampshire, Colorado College and the California Institute of Technology. The researchers are scheduled to present their findings Friday, Nov. 1, in Los Angeles at the annual meeting of the Society of Vertebrate Paleontology.

They concluded that decreased body size "seems to be a common evolutionary response" by mammals to extreme global warming events, known as hyperthermals, "and thus may be a predictable natural response for some lineages to future global warming."

The PETM lasted about 160,000 years, and global temperatures rose an estimated 9 to 14 degrees Fahrenheit at its peak. The smaller, later event analyzed in the latest study, known as ETM2 (Eocene Thermal Maximum 2), lasted 80,000 to 100,000 years and resulted in a peak temperature increase of about 5 degrees Fahrenheit.

Teeth and jaw fossils of early hoofed mammals and primates that spanned this later climatic event were collected in Wyoming's Bighorn Basin, and the size of molar teeth was used as a proxy for body size. The researchers found that body size decreased during ETM2, but not as much as the dwarfism seen in PETM fossils.

For example, the study revealed that a lineage of early horses the size of a small dog, called Hyracotherium, experienced a body-size decrease of about 19 percent during ETM2. The same horse lineage showed a body-size decrease of about 30 percent during the PETM. After both events, the animals rebounded to their pre-warming size.

"Interestingly, the extent of mammalian dwarfism may be related to the magnitude of the hyperthermal event," said team member Abigail D'Ambrosia of the University of New Hampshire.

An ancient ungulate called Diacodexis decreased about 20 percent in size during ETM2, and the primate Cantius decreased 8 percent.

The burning of fossil fuels and the resulting release of heat-trapping greenhouse gases—mainly —is blamed for present-day climate warming. The ancient warming events may have been caused by the release of seabed methane clathrates, a kind of methane ice found in ocean sediments, though this topic remains an area of active research, Gingerich said. Methane is a more potent greenhouse gas than carbon dioxide, and atmospheric methane is eventually transformed into carbon dioxide and water.

The parallels between ancient hyperthermals and modern-day warming make studies of the fossil record particularly valuable, said team member Will Clyde of the University of New Hampshire.

"Developing a better understanding of the relationship between mammalian body size change and greenhouse gas-induced global warming during the geological past may help us predict ecological changes that may occur in response to current changes in Earth's climate," Clyde said.

In 2006, Gingerich proposed that mammalian dwarfing could be a response to the lower nutritional value of plants grown under elevated carbon dioxide levels. Under such conditions, plants grow quickly but are less nutritious than they would normally be.

Animals eating such plants might adapt by becoming smaller over time. Evidence from the ETM2 fossils is consistent with that hypothesis, and research on the topic is ongoing, Gingerich said.

Explore further: Satellites sees a question mark in Tropical Storm Ana

Related Stories

Dating an ancient episode of severe global warming

Jun 15, 2011

Using sophisticated methods of dating rocks, a team including University of Southampton researchers based at the National Oceanography Centre, Southampton, have pinned down the timing of the start of an episode ...

New findings could sway thought on climate change

Oct 20, 2010

(PhysOrg.com) -- A newly published paper written by a University of Nebraska-Lincoln researcher and his team could influence the way scientists think about global warming and its effects.

Recommended for you

NASA image: Fires in the Egypt River Delta

1 hour ago

This NASA satellite image is of the Egyptian River Delta. Actively burning areas, detected by MODIS's thermal bands, are outlined in red. Each hot spot, which appears as a red mark, is an area where the thermal ...

Terra Satellite sees Tropical Storm Ana over Hawaii

1 hour ago

Tropical Storm Ana made a slow track west of the Hawaiian islands over the last couple of days, and by Oct. 20 was moving westward away from the main Hawaiian islands and heading toward the northwest Hawaiian ...

Asbestos likely more widespread than previously thought

7 hours ago

Naturally occurring asbestos minerals may be more widespread than previously thought, with newly discovered sources now identified within the Las Vegas metropolitan area. The asbestos-rich areas are in locations not previously ...

User comments : 26

Adjust slider to filter visible comments by rank

Display comments: newest first

NikFromNYC
1.6 / 5 (25) Nov 02, 2013
"...mainly carbon dioxide—is blamed for present-day climate warming."

EXHIBIT A: concerning sea surface temperatures (SST) thanks to Climategate:

"From: Phil Jones [p.jones@uea.ac.uk] Sent: Thu 07/05/2009 15:17
To: Lockwood, M (Mike)
Cc:
Subject: RE: Quick reply and another quick question ....
Attached a paper and a box in a longer article that do similar things to what you've
done.
So I think it's been done, unless you think otherwise.
The box is on page S20-21 of the bigger pdf. This is part of a much bigger article
on the State of the Climate System 2008 which will appear later in the year.
Bottom line - the no upward trend has to continue for a total of 15 years before
we get worried. We're really counting this from about 2004/5 and
not 1998. 1998 was warm due to the El Nino."

EXHIBIT B: SST update thanks to satellites:
http://www.woodfo...adsst3gl

EXHIBIT C: Phil Jones swimming in petrodollars:
http://mpc.kau.ed...nes.aspx
NikFromNYC
1.5 / 5 (23) Nov 02, 2013
BLISTERING EXHIBIT D: The postwar high CO₂ variation in sea surface temperature is exactly mirrored by the former low CO₂ period!
http://www.woodfo.../to:2013
Zephir_fan
Nov 02, 2013
This comment has been removed by a moderator.
NikFromNYC
1.5 / 5 (23) Nov 02, 2013
Tell that to the Anerican Chemical Society president Breslow and chemistry Nobel Prize winner Chalfie who were on my Ph.D. defense committee, Mister Zepir_fan.

-=NikFromNYC=-, Ph.D. (Hammett Award winner in the organic/carbon division at Columbia, with a three year postdoc at Harvard with Whitesides)

P.S. Thanks for being the representative public face of Climate Commandoism, where opinions matter but data is damned.
NikFromNYC
1.5 / 5 (22) Nov 02, 2013
Speaking of sea surface temperatures, I found a satillite image of Zephir trolling away:
http://postimg.or...qe88lo5/

Monkeying around is all Climatology doomsday cult members have left to offer since their rogue bet on the weather went sour, boo hoo.

Boo hoo hoo hoo, oceans of years because the end of the world was once again called off, the UFOs didn't land, the Mayan calender didn't lead to a great purifying Singularity that stuck it to The Man.
NikFromNYC
1.6 / 5 (21) Nov 02, 2013
Typo: oceans of years = oceans of tears

Not working on a Saturday, indeed, but...iPhone...but asleep lap cat...but flannel sheets....
runrig
4.2 / 5 (10) Nov 02, 2013
Bottom line - the no upward trend has to continue for a total of 15 years before
we get worried. We're really counting this from about 2004/5 and
not 1998. 1998 was warm due to the El Nino."


Err that would be 2019/20 then? Or is my maths just crap? Don't think so.

"The Smith and Reynolds (2005)
surface (land and ocean) temperature dataset in use at
the National Oceanic and Atmospheric Administration
(NOAA) National Climatic Data Center (NCDC)
places 2005 as the warmest year on record, although
the 2005 anomaly was statistically indistinguishable
from the previous record temperature of 1998 (Fig. 1).
THIS RECORD WARMTH IN 2005 IS NOTABLE GIVEN THAT IT OCCURRED
IN THE ABSENCE OF A STRONG El NINO ANOMALY."

http://journals.a...87-6-801
runrig
4.6 / 5 (9) Nov 02, 2013
BLISTERING EXHIBIT D: The postwar high CO₂ variation in sea surface temperature is exactly mirrored by the former low CO₂ period!
http://www.woodfo.../to:2013


Keep going Nik: Several own goals coming my way.

The "dip" is well known and due to "global dimming" from a time when pollutants were particularly high in the atmosphere.

http://en.wikiped..._dimming
"Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4% reduction over the three decades from 1960–1990.

And if we start your graph earlier...
http://www.woodfo.../to:2013
We see that the continuation takes the Earth to a new, higher level.
runrig
4.5 / 5 (8) Nov 02, 2013
EXHIBIT C: Phil Jones swimming in petrodollars:
http://mpc.kau.ed...nes.aspx


From the article you linked in another thread Nik:…
http://www.psycho...nce.html

""This conspiratorial element provides a breeding ground for the personal and professional attacks on scientists that seemingly inevitably accompany science denial.""

Exactly.
But of course you are no denialist… you're just an activist.
Zephir_fan
Nov 02, 2013
This comment has been removed by a moderator.
NikFromNYC
1.4 / 5 (20) Nov 02, 2013
runrig, the NOAA data set simply falsifies claims of there being any difference in warming trend from the same old boring trend that is utterly defying CO₂:

EXHIBIT ONE: http://postimg.or...827ew8l/

EXHIBIT TWO: http://s22.postim...te_B.gif

EXHIBIT THREE: http://s10.postim...logy.gif

Strike three, you lose. The NOAA data shows a linear trend that makes a mockery of the PR firm tutored propaganda claim that oh, the lack of warming is no big deal since the last (unchanging!!!) decade was the hottest on record.

Ignoring this simple fact, the simple lack of real support for AGW in real thermometer records, as you cheer on dishonestly misleading graphology meant to *deceive* policy makers and the public, is simply damning. You can retain the low information voter crowd a bit longer, but simple data charts convert reasonable critical thinkers into skeptics, and year after year, they speak out more and more, now including cl
NikFromNYC
Nov 02, 2013
This comment has been removed by a moderator.
NikFromNYC
1.2 / 5 (19) Nov 02, 2013
(continued from cut off post)...now including head of climatology at Georgia Tech, Judith Curry, who has this year turned from a mere critic into a full blown IPCC bashing skeptic:

"The prospect of the current hiatus lasting until the mid 2030′s (as per the stadium wave and related theories of natural variability) is a decisive test for IPCC's AGW detection arguments. Detection of AGW is a prerequisite for the IPCC's attribution arguments. The IPCC's statements of 95% confidence that most of the warming is anthropogenic, and expectations of substantial warming between now and 2036, has the IPCC skating on very thin ice, in my opinion."

...and a new generation of climatologists represented by Dr. Tasmin Edwards is suddenly directly confronting Michael "Hide The Decline In Proxy Data" Mann:
https://twitter.c...76027393

"You are seriously calling Rob a denier for criticising your work, M? That's pretty strong to call a prof climate colleague."
NikFromNYC
1.2 / 5 (18) Nov 02, 2013
Teech2 wrote: "It just plays well with my previous comment here, where I did say, that the evolution of dinosaurs and giant Holocene mammals was just an adaptation to the cold weather in this period...."

I seem to remember that the level of available breathable oxygen was also elevated in the reign of monster insects and big beasts.
runrig
4.4 / 5 (7) Nov 02, 2013
runrig, the NOAA data set simply falsifies claims of there being any difference in warming trend from the same old boring trend that is utterly defying CO₂:

EXHIBIT ONE: http://postimg.or...827ew8l/

What? That shows a mean line through a plot – not arbitary just a mean.
And below that a trend line of that plot – showing an increase of ~0.8C.
EXHIBIT TWO: http://s22.postim...te_B.gif

again as above … and so what the second half is similar to the 1st, separated by the global dimming period. A contiunung trend attenuated in the middle.
EXHIBIT THREE: http://s10.postim...logy.gif

I've just gone to the original page on NOAA and downloaded the data into excel – and guess what – the sum comes out at ZERO. Therefore the line is a true mean of the plot.
What you did in your version is a mystery. edit - Perhaps not - merely more obfuscation to further your "activist" agenda.

Strike three, you lose

Yes you certainly do.
runrig
4.4 / 5 (7) Nov 02, 2013
Nik: re your post on Curry/Mann and anyone else who twittered......

All irrelevant. Moaning from people left behind and isolated/embittered by the science, which relentlessly goes in the same direction (by 32:1).

Arguments and opinions by whoever have no weight whatever, merely highlighting people pushing back/forth with their entrenched opinions. As I said somewhere on here, it is peer reviewed science that counts not the noise made by this tiny minority of "skeptics" or by the media in their thrall.
NikFromNYC
1.3 / 5 (16) Nov 02, 2013
runrig, your NOAA line is an utter misfit to the data, period. It goes sideways as the data goes up linearly across it.

Zephir_fan, the fifth floor doorman building view from what you call "mom's basement" is that of Broadway, USA and Riverside park, and I included a shot of one of "mom's" two sputter coaters for ya:
http://postimg.or...3fz56e6/

The argon plasma sputter coater pays my bills, not Big Oil like Michael Mann himself claimed for one of this month's Phys.org threads I was posting in!
http://postimg.or...72bs4q5/
NikFromNYC
1.3 / 5 (16) Nov 02, 2013
runrig, the NOAA's own plot page reveals that rather than being a mean of *all* the data they left out the latest and hottest 12 years by drawing their "zero" line thus:
"The graph shows average annual global temperatures since 1880 compared to the long-term average (1901-2000)."
http://www.climat...perature

This technical detail is not in any way the crux of my NOAA argument, though you are mixing up lots of brew here as if it was. The use of a sideways linear line and bright red recent emphasis to conceal instead of reveal the linearity of the data and near perfect precedence for recent variation is my point.
NikFromNYC
1.3 / 5 (16) Nov 02, 2013
runrig, Judith Curry now fully represents the cutting edge of the study of natural climate variation:
http://link.sprin...2#page-1

...meanwhile Michael Mann is out suing people, cheering the Marcott 2013 hockey stick whose input data makes a mockery of the result:

EXHIBIT X: http://postimg.or...26bsi5p/

EXHIBIT Y: http://s15.postim...2013.jpg

If you agree with Mann that my posts here "smell of Koch" we'll call that utterly unprofessional Exhibit XXX.

runrig
4.4 / 5 (7) Nov 02, 2013
runrig, your NOAA line is an utter misfit to the data, period. It goes sideways as the data goes up linearly across it.


Of course it does – as it's a mean of the graph. Equal areas above/below which my summation of the data points in excel confirms

http://www.climat...perature
ftp://ftp.ncdc.no...mean.dat
Egleton
1.6 / 5 (14) Nov 02, 2013
I had a look at you links Nik. I am totally convinced now.
Egleton
1.9 / 5 (14) Nov 02, 2013
Try and get some sleep.
runrig
4.4 / 5 (7) Nov 02, 2013
runrig, Judith Curry now fully represents the cutting edge of the study of natural climate variation:
http://link.sprin...2#page-1


She represents a focus of denialism – like bees around a honey-pot. Now those bees do NOT represent anyone who matters. Sorry.

BTW: I have no problem with the paper you link too. I also think that a +AMO phase will penetrate warming into Eurasian waters. This would require a strong +NAO to blow SW winds through the Norwegian/Barents seas.
However … however, as ever in Climate/Meteorology it is hard to separate cause/effect and there absolutely ARE multiple overlying cycles. The AMO is in addition to an overlying AGW signal (or the other way around it you prefer).
NikFromNYC
1.3 / 5 (16) Nov 02, 2013
I'm not in climate threads to convince the religious, only to expose them as being so. Here lie nutcases and a real expert who calls me a denier who himself denies the bluntly clear alarm busting linearity of his own posted NOAA data set, for all to witness. Ridiculing basic data plots that falsify alarmist headlines and official hockey sticks is PR suicide which marks even expert runrig as a fanatic, but the MET office he retired from has its reputation pegged to the weather outside, during the least active hurricane era of any US presidency.

(A) THE TREND REMAINS THE SAME.
(B) HOCKEY STICK "SCIENCE" IS BASED ON SPURIOUS ARTIFACTS.

I posted proof of this, simple proof, denial of which breaks logic itself.

The standard Church & White Sea level study update of 2010 also shows NO TREND CHANGE in worldwide tide gauge data going back 150 years:
http://oi51.tinyp...koix.jpg

Again, I committed the grave sin of adding a trendline after extracting the yellow tide gauge plot.
runrig
4.5 / 5 (8) Nov 02, 2013
I posted proof of this, simple proof, denial of which breaks logic itself.


And I posted clear and simple refutation of your "proof" including a long list of data that the discerning can put into Excel and see that indeed they cancel to zero. The mean line did not bias to the warm.

You do understand how graphs and their means/trends are drawn do you Nik?
That's the kindest interpretation I can come up with because you're certainly making no kind of sense.
runrig
4.3 / 5 (6) Nov 02, 2013
marks even expert runrig as a fanatic, but the MET office he retired from has its reputation pegged to the weather outside, during the least active hurricane era of any US presidency.


Shall we go into all the other weather forecasts that can be used by the desperate to denigrate by association Climate forecasting.
Weather prediction is akin to prediction the spikes on your graphs rather than a trend line through them.

Forecast made UKMO May 15, 2013
named storms 14*
Hurricanes 9*
Actual activity
Named 12*
Hurricanes 2*
* June–November only

BTW: Current date is 2nd Nov

PS: Did you get the bit about things other than temps creating Extra-tropical Storms? The annoying little complication like winds aloft and dry mid-tropospheric air advected from the Sahara this year. It's all so easy when your ignorant of such things, isn't it Nik?
runrig
4.3 / 5 (6) Nov 02, 2013
The standard Church & White Sea level study update of 2010 also shows NO TREND CHANGE in worldwide tide gauge data going back 150 years..

Nik: From that paper ….
" Using the yearly average data, we computed trends for successive 16 year periods (close to the length of the altimeter data set) from 1880 to the present. We find maxima in the rates of sea-level rise of over 2 mm year−1 in the 1940s and 1970s and nearly 3 mm year−1 in the 1990s"
"The rate of SL rise as measured both by the satellite altimeter record and the in situ reconstruction of about 3 mm/year since 1993 is near the upper end of the SL projections for both the Intergovernmental Panel on Climate Change's Third and Fourth reports"

http://www.cmar.c..._15.html

""This data has shown a more-or-less steady increase in GMSL of around 3.2 ± 0.4 mm/year over that period. This is more than 50% larger than the average value over the 20th century".
NikFromNYC
1.3 / 5 (16) Nov 02, 2013
runrig, Tony Banton, is the type of gentleman who will carry the torch of real climate science back onto the field of true dynamic discourse, post-hype, in the Atomic Age, once all the rage isn't some odd religion. I respect runrig, damn it, and sincerely regret that I cannot in good faith treat him as a clown, nor afford the age 48 spare time required to hash out every detail. The human race, at least in the West, is made stronger by such stark and competent division of labor and of intuitive opinion, as opposed to stark uniformity.

All great souls are fanatics, so Tony is mere family.
Howhot
4.3 / 5 (6) Nov 02, 2013
Good old @NikfoolfromNy still pushes more and more denier crap that has already been discredited, lets look a two of these claim shall we;
(A) THE TREND REMAINS THE SAME.
(B) HOCKEY STICK "SCIENCE" IS BASED ON SPURIOUS ARTIFACTS.


Ocean temperatures certainly haven't remained the same.
http://onlinelibr...abstract
A little youtube musical for your NY mind.
http://www.youtub...TMR9pcrI
Temperature change corelation to atmospheric CO2 levels.
http://www.skepti...nge.html
Etc... etc. even a PhD can be delusional

Let see if point B even makes sense; I don't know what hockey-stick *science* is except to be some derogatory statement from an delusional global warming denier. Here is the hockey stick

http://skepticals...iate.pdf