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:2/27/2017)... 2017   Strategic Cyber Ventures , the industry,s ... a $3.5 million investment in  Polarity , the first ... is DC based and is led by cybersecurity veterans ... Ron Gula , also a longtime cybersecurity veteran ... this series A round of funding. This new funding ...
(Date:2/24/2017)... Spain , Feb. 24, 2017  EyeLock LLC, a ... demonstrate its elite iris biometric solution on the ... X16 LTE at Mobile World Congress 2017 ... Qualcomm,s Booth in Hall 3, Stand 3E10. ... the Qualcomm Haven™ security platform—a combination of ...
(Date:2/21/2017)... ARMONK, N.Y. and PORTLAND, Ore. ... IBM ) and the Avamere Family of Companies (Avamere ... Care) today announced a six-month research study that will ... caregivers improve eldercare at senior living and health centers. ... facilities, Avamere hopes to gain insights into physical and ...
Breaking Biology News(10 mins):
(Date:3/23/2017)... VILLAGE, Colo. , March 23, 2017  Agriculture ... in Series A financing and note conversion to commercialize ... Cool Planet is focused on developing products that are ... nearly $30 million in the last 18 months. This ... and North Bridge Venture Partners. The ...
(Date:3/22/2017)... 22, 2017  Ascendis Pharma A/S (Nasdaq: ASND), ... technology to address significant unmet medical needs in ... full year ended December 31, 2016. ... company as we broadened our pipeline and pursued ... disease company with an initial focus on endocrinology," ...
(Date:3/22/2017)... ALBANY, New York , March 22, 2017 /PRNewswire/ ... market is largely fragmented, states a research report by ... Sanofi S.A., Pfizer Inc., Amgen Inc., and AbbVie Inc., ... market in 2015. The prominent players in this market ... to expand their product portfolio, which is likely to ...
(Date:3/22/2017)... ... March 21, 2017 , ... Premier executive recruitment firm, Slone Partners, is ... by Hunt Scanlon Media. , Hunt Scanlon Media is one of the ... global news source in the human capital sector. , “It is a great honor ...
Breaking Biology Technology: