Navigation Links
Temperature constancy appears key to tropical biodiversity
Date:7/20/2010

CAMBRIDGE, Mass., July 20, 2010 -- The tropics owe their stunning biodiversity to consistent year-round temperatures, not higher temperatures or more sunlight, according to a novel survey of insect diversity at different latitudes and at different points in the planet's history.

The finding, presented this week in the journal Paleobiology by researchers from Harvard University, Simon Fraser University, and Brandon University, may finally answer a question that has dogged scientists for centuries.

It also suggests, intriguingly, that the world is likely far less diverse today than it was tens of millions of years ago, when the entire Earth had consistent year-round temperatures, much like the modern tropics.

"The latitudinal diversity gradient has been recognized for 150 years as one of the most general observations in nature, and has produced more explanatory hypotheses than nearly any other observation," says co-author Brian D. Farrell, professor of biology at Harvard. "We show that when most of today's organisms were diversifying, up through the Eocene, the world lacked pronounced seasonality, more like today's tropics, even in areas where the temperature was low."

"It appears it's not the heat of the tropics that promotes diversity; it's the newer seasons of the temperate zone that depress diversity."

Scientists' explanations for tropical biodiversity have tended to focus on the greater heat and light found closer to the equator, and to a lesser extent the low seasonality of the tropics, where average temperature in the hottest and coolest months may vary by only a few degrees.

"These factors tend to change together as you travel away from the equator toward the poles, leaving it difficult to separate their individual effects on diversity," says lead author S. Bruce Archibald, a research associate at Simon Fraser University, Harvard's Museum of Comparative Zoology, and the Royal British Columbia Museum. Archibald conducted the research for his doctoral dissertation at Harvard, where Farrell was his advisor.

Farrell, Archibald, and colleagues engaged in a kind of time travel, invoking the fossil record to solve this conundrum. They compared modern insect diversity at the Harvard Forest in Petersham, Mass., and in a Costa Rican jungle against that seen at the 52.9-million-year-old McAbee fossil bed in British Columbia, noted for its exceptionally well preserved insects. At the time the McAbee fossils were created, Earth's climate was far less seasonal at all latitudes, allowing tropical species such as palm trees and crocodiles to live in what is now the high Arctic.

The scientists' discovery that the ancient Canadian site's insect diversity mirrors that of the modern Costa Rican jungle, despite a marked difference in latitude, suggests that it's seasonality, not heat or light, that drives biodiversity.

"Planet Earth and life have coevolved for well over a billion years, and this is yet additional evidence of the consequent intertwining of global physical and biological phenomena," Farrell says.


'/>"/>

Contact: Steve Bradt
steve_bradt@harvard.edu
617-496-8070
Harvard University
Source:Eurekalert

Related biology news :

1. Turtles alter nesting dates due to temperature change says ISU researcher
2. Purdue study suggests warmer temperatures could lead to a boom in corn pests
3. Plants take a hike as temperatures rise
4. Making a point: Picoscale stability in a room-temperature AFM
5. Elevated water temperature and acidity boost growth of key sea star species: UBC researchers
6. Highest ever winter water temperatures recorded
7. NIST calculations may improve temperature measures for microfluidics
8. River flow and temperature limit trout numbers
9. ATP is a key to feel warm temperature
10. North Atlantic fish populations shifting as ocean temperatures warm
11. How plants feel the temperature rise
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/15/2016)... Jan. 15, 2016 Recent publicized breaches in ... find new ways to ensure data security and user ... and Android that ties a user,s ... it into a hardware authorization token. Customer service agents ... fingerprint on their KodeKey enabled device to verify their ...
(Date:1/11/2016)... Calif. , Jan. 11, 2016 Synaptics ... human interface solutions, today announced that its ClearPad ® ... integration (TDDI) products won two separate categories in the ... Mobile Innovator and Best Technology Breakthrough. The Synaptics ® ... cost, a simplified supply chain, thinner devices, brighter displays ...
(Date:1/8/2016)... -- NXTD ), a company focused on ... privately held leading direct seller of vacation and entertainment ... company announced that on December 31, 2015, that WorldVentures ... to develop a proprietary new wireless smart card for ... unique smart wallet that serves to securely store all ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... for the development of future natural products for crop protection. ... development center in Israel and invests ... has a variety of products adapted to regional ... more than 35 counties worldwide. ... Timorex Gold ® is used to control a broad ...
(Date:2/6/2016)... ... 06, 2016 , ... The Center for Excellence in Education (CEE) will sponsor ... on Wednesday February 10, 2016. This Bite of Science session, hosted by the ... at 1500 Remount Road in Front Royal, VA from 5:00 p.m. to 8:00 p.m. ...
(Date:2/5/2016)... , Feb. 5, 2016  In the pharmaceutical ... for a host of launch activities including the identification ... this launch activity is especially high in the oncology ... Best Practices and the Role of Medical Affairs ... companies focused on oncology therapies find better ways to ...
(Date:2/5/2016)... 5, 2016 Australian-US drug discovery and development company, ... appointment of a new Chairman, Mr John O,Connor , ... immediately. James Garner , has also been ... former Acting CEO, Mr Iain Ross , will resume ... --> James Garner , has also been formally appointed ...
Breaking Biology Technology: