Live fast, die young--body size sets scale of life

Submitted by Marie Gilbert
Phone: (907) 474-7412
09/08/06

FAIRBANKS, Alaska--Size really does matter. The rate at which an organism grows and functions--its metabolic rate--plays a key role in how fast that organism lives and how young it dies.

"Metabolism can potentially provide a theoretical unification for ecology similar to that which genetics has provided for evolutionary biology," said James Brown, distinguished professor of biology, University of New Mexico, and the 2006 Institute of Arctic Biology Irving-Scholander Memorial Lecturer.

Brown will present "Microbes to Monsters: Body Size Sets the Scale of Life" at 7 p.m., Sept. 14, in Elvey Auditorium on the University of Alaska Fairbanks campus. The lecture is free and open to the public.

As animals get bigger, pulse rates slow and life spans lengthen. For most animals their metabolic rate scales to the three-quarter power of their mass. A cat, for example, has a mass about 100 times that of a mouse and has a metabolism about 31 times greater than a mouse.

"Living things vary in size by an amazing 21 orders of magnitude, from the smallest bacteria to whales and sequoias. All these organisms use the same basic molecules and reactions to transform energy and materials, build structure, and power activity," said Brown.

"This scaling of metabolic rate explains the effects of body size on most biological processes, from processing of energy and materials within cells, reproduction and lifespan of individual organisms, carbon and nutrient cycling in ecosystems, and to rates of molecular evolution," said Brown. "The scaling of metabolism reveals a unity of life that underlies its enormous diversity and complexity."

The Irving-Scholander Memorial Lecture Series began in 1981 to honor the scientific legacies of Laurence Irving, founding director of the Institute of Arctic Biology, and his colleague Per Scholander.

For more information go to www.iab.uaf.edu/events/eventsseminars.php or call (907) 474-7640.

Contact: Marie Gilbert, public information officer, UAF Institute of Arctic Biology,at (907) 474-7412 or via e-mail at marie.gilbert@uaf.edu. Julie Jackson, student assistant, UAF Institute of Arctic Biology, at (907) 474-7640 or via e-mail at fsjkj7@uaf.edu. Dorothy Parkerson, assistant to the director, UAF Institute of Arctic Biology, at (907) 474-7649 or via e-mail at fndrp@uaf.edu.