Navigation Links
Better food makes high-latitude animals bigger
Date:1/28/2010

New research suggests that animals living at high latitudes grow better than their counterparts closer to the equator because higher-latitude vegetation is more nutritious. The study, published in the February issue of The American Naturalist, presents a novel explanation for Bergmann's Rule, the observation that animals tend to be bigger at higher latitudes.

Ever since Christian Bergmann made his observation about latitude and size in 1847, scientists have been trying to explain it. The traditional explanation is that body temperature is the driving force. Because larger animals have less surface area compared to overall body mass, they don't lose heat as readily as smaller animals. That would give big animals an advantage at high latitudes where temperatures are generally colder.

But biologist Chuan-Kai Ho from Texas A&M University wondered if there might be another explanation. Might plants at higher latitudes be more nutritious, enabling the animals that eat those plants to grow bigger?

To answer that question, Ho along with colleagues Steven Pennings from the University of Houston and Thomas Carefoot from the University of British Columbia, devised a series of lab experiments. They raised several groups of juvenile planthoppers on a diet of cordgrass, which was collected from high to low latitudes. Ho and his team then measured the body sizes of the planthopppers when they reached maturity. They found that the planthoppers that fed the high-latitude grass grew larger than those fed low latitude grass.

The researchers performed similar experiments using two other plant-eating speciesgrasshoppers and sea snails. "All three species grew better when fed plants from high versus low latitudes," Ho said. "These results showed part of the explanation for Bergmann's rule could be that plants from high latitudes are better food than plants from low latitudes." Although this explanation applies only to herbivores, Ho explained that predators might also grow larger as a consequence of eating larger herbivores.

"We don't think that this is the only explanation for Bergmann's rule," Ho added. "But we do think that studies of Bergmann's rule should consider ecological interactions in addition to mechanisms based on physiological responses to temperature."

It's not known why the higher-latitude plants might be more nutritious. But research in Pennings's lab at the University of Houston offers a clue. Pennings has shown that plants at low latitudes suffer more damage from herbivores than those at higher latitudes. Ho and Pennings suggest that perhaps lower nutrition and increased chemical defenses are a response to higher pressure from herbivores.


'/>"/>

Contact: Kevin Stacey
kstacey@press.uchicago.edu
773-834-0386
University of Chicago Press Journals
Source:Eurekalert

Related biology news :

1. A virtual liver, a better chance of life
2. Sweet corn study provides large-scale picture of better fields
3. Research project yields better understanding of the defective protein that causes cystic fibrosis
4. When it comes to fish families, the bigger and bossier the better
5. Gaining a better picture of lung disease
6. Bigger not necessarily better, when it comes to brains
7. Mantis shrimps could show us the way to a better DVD
8. Flu focus: NIH project aims for better drugs
9. A major step in making better stem cells from adult tissue
10. U of C chemists discover recipe to design a better type of fuel cell
11. Team finds a better way to watch bacteria swim
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... , April 11, 2017 No ... but researchers at the New York University Tandon ... of Engineering have found that partial similarities between ... systems used in mobile phones and other electronic ... The vulnerability lies in the fact ...
(Date:4/5/2017)... LONDON , April 4, 2017 KEY ... is anticipated to expand at a CAGR of 25.76% ... neurodegenerative diseases is the primary factor for the growth ... full report: https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The ... of product, technology, application, and geography. The stem cell ...
(Date:3/30/2017)... Trends, opportunities and forecast in this market ... (fingerprint, AFIS, iris recognition, facial recognition, hand geometry, vein ... use industry (government and law enforcement, commercial and retail, ... others), and by region ( North America ... Pacific , and the Rest of the World) ...
Breaking Biology News(10 mins):
(Date:6/20/2017)... ... June 20, 2017 , ... ... determine the adulterants which pose the most likely threat to their products at ... this year. , IFT's annual food expo attracts over 20,000 attendees representing ...
(Date:6/20/2017)... ... June 20, 2017 , ... GigaGen Inc ., a ... repertoires, announces launch of its new Surge(TM) Discovery service at the ... GigaGen, will present on Surge at the conference. , Surge is the new, ...
(Date:6/19/2017)... ... ... A colony of healthy honey bees is like a superorganism--individual bees provide ... containing nutrients necessary for growth and survival. Better nutrition gives the colony a strong ... a decline in honey bee health. Sick and weakened bees diminish the colony's resiliency, ...
(Date:6/15/2017)... ... 2017 , ... New resistant soybean and cotton cropping systems ... amaranth and other broadleaf weeds resistant to glyphosate. But scientists with the Weed ... known to drift and to cause harm to sensitive, off-target broadleaf plants. , ...
Breaking Biology Technology: