Featured Research

from universities, journals, and other organizations

Better food makes high-latitude animals bigger

Date:
January 29, 2010
Source:
University of Houston
Summary:
Researchers have found a possible new solution to a 163-year-old puzzle. Ecological factors can now be added to physiology to explain why animals grow bigger in the cold. Their results offer new insight to Bergmann's rule that animals grow larger at high, cold latitudes than their counterparts closer to the equator, hypothesizing that better food makes high-latitude animals bigger.

Credit: Amanda Thronson

Thanks to a pair of University of Houston researchers who found a possible new solution to a 163-year-old puzzle, ecological factors can now be added to physiology to explain why animals grow bigger in the cold.

Related Articles


Their results were published in the February issue of the American Naturalist, offering new insight to Bergmann's rule that animals grow larger at high, cold latitudes than their counterparts closer to the equator. While traditional explanations have been based on body temperature being the driving force of this phenomenon, this group of community ecologists hypothesize that better food makes high-latitude animals bigger.

Chuan-Kai Ho, a Ph.D. graduate from UH in ecology and evolution, his adviser and UH professor of biology and biochemistry Steven Pennings, and their collaborator Thomas Carefoot from the University of British Columbia opened up a new line of study into Bergmann's rule. The research program in Pennings' lab over the last decade has offered the most extensive work done on the general problem of latitudinal variation in plant-herbivore interactions. This latest finding from Pennings' groundbreaking research at UH on this subject came from one of Ho's doctoral dissertation chapters.

"Because the American Naturalist is one of the top journals in our field, publishing at this level is a mark of great success for a Ph.D. student," Pennings said. "It's also a reflection of the strength of our graduate program in the ecology and evolution division of UH's department of biology and biochemistry."

Ho, now a postdoctoral student at Texas A&M at Galveston's Armitage & Quigg Laboratory, also has another chapter from his UH dissertation on salt marsh food webs published in Ecology, another top journal in the field. Pennings received a doctoral dissertation improvement grant for Ho in 2007-2008 from the National Science Foundation that provided funding for Ho to run chemical analyses on leaves from different latitudes to assess their nutritional content.

Studying three different plant-eating species -- grasshoppers, planthoppers and sea snails -- collected from along the Atlantic coast to Japan, respectively, the researchers fed these herbivores plants from both high and low latitudes and found that they all grew better when fed plants from the higher latitudes. This indicates that Bergmann's rule could reflect that plants from high latitudes provide better food than those from low latitudes. These latest findings, according to Ho, indicate that studies of Bergmann's rule should consider ecological interactions in addition to the more traditional theories of physiology based on responses to temperature.

Over the years, work in Pennings' lab has shown that, although low-latitude plants are less nutritious and better protected by chemical defenses, they experience heavy damage from herbivores, which are more abundant at low latitudes. Future study, Pennings adds, should focus on why there are more herbivores at lower latitudes despite the lower-quality food sources. A likely explanation is that herbivore populations are limited at high latitudes by a short growing season and high death rates during cold winters.

"While the explanations discovered in our current study only apply to herbivores, it may be that carnivores and omnivores also might grow larger as a consequence of eating larger herbivores," Ho said. "Examining such patterns and underlying mechanisms in nature will help us understand what currently is going on and what might happen down the line to our ecosystems."


Story Source:

The above story is based on materials provided by University of Houston. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chuan-Kai Ho, Steven C. Pennings, and Thomas H. Carefoot. Is Diet Quality an Overlooked Mechanism for Bergmann’s Rule? The American Naturalist, 2010; 175 (2): 269 DOI: 10.1086/649583

Cite This Page:

University of Houston. "Better food makes high-latitude animals bigger." ScienceDaily. ScienceDaily, 29 January 2010. <www.sciencedaily.com/releases/2010/01/100128105708.htm>.
University of Houston. (2010, January 29). Better food makes high-latitude animals bigger. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2010/01/100128105708.htm
University of Houston. "Better food makes high-latitude animals bigger." ScienceDaily. www.sciencedaily.com/releases/2010/01/100128105708.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Praying Mantis Looks Long Before It Leaps

Praying Mantis Looks Long Before It Leaps

Reuters - Innovations Video Online (Mar. 5, 2015) Slowed-down footage of the leaps of praying mantises show the insect&apos;s extraordinary precision, say researchers. Video provided by Reuters
Powered by NewsLook.com
Octopus Grabs Camera and Turns It Around On Photographer

Octopus Grabs Camera and Turns It Around On Photographer

Buzz60 (Mar. 5, 2015) A photographer got the shot of a lifetime, or rather an octopus did, when it grabbed the camera and turned it around to take an amazing picture of the photographer. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
Ringling Bros. Eliminating Elephant Acts

Ringling Bros. Eliminating Elephant Acts

AP (Mar. 5, 2015) The Ringling Bros. and Barnum & Bailey Circus is ending its iconic elephant acts. The circus&apos; parent company, Feld Entertainment, told the AP exclusively that the acts will be phased out by 2018 over growing public concern about the animals. (March 5) Video provided by AP
Powered by NewsLook.com
Raw: Tourists Visit Rare Grey Whales in Mexico

Raw: Tourists Visit Rare Grey Whales in Mexico

AP (Mar. 4, 2015) Once nearly extinct, grey whales now migrate in their thousands to Mexico&apos;s Vizcaino reserve in Baja California, in search of warmer waters to mate and give birth. Tourists flock to the reserve to see the whales, measuring up to 49 feet long. (March 4) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins