GORILLAS -CHIMPS- *HUMANS

CHIMPS AND GORILLAS, WHETHER IN the wild or zoos, rarely run, or even walk much, Dr. Lieberman said, except for a mile or two in search of food.

But they rapidly clamber up and down trees and grapple during fights. They are strength and power athletes.

We humans, on the other hand, tend to be built for endurance and frequent, moderate physical activity, he said, with a fossil record showing gradual changes in our skeletons most likely caused by and promoting plenty of walking and occasional distance running as we hunted and gathered.

UNLIKE GORILLAS AND CHIMPS, we were born to run.

No chimpanzees or gorillas are in training for a fall marathon - and the look and function of their hearts reflect that, according to a major new study of the health and evolution of cardiac muscles.

The study which involved scanning the heart of gorillas and chimpanzees and a wide variety of humans, indicates that hearts adapt in telling ways to the needs of their owners.

The findings likewise suggest that not getting enough of the right kind of exercise could mean that our hearts start to look just a little bit less human, and could affect our long-term health.

In general, mammalian hearts are quite malleable, they change in response to the demands placed on them. Recently, I wrote about a study showing that the hearts of elite swimmers and runners differ from one another slightly in shape and function and differ substantially from the hearts of those who aren't athletes.

But until now, researchers had not examined whether and how this changing of the heart , known as its plasticity, might have played out during our evolution as a species and what that process could mean for our heart health today.

So, for the new study, which was published in September in PNAS, scientists from Harvard University and other institutions decided to compare, for the first time, the looks and workings of human hearts with those of our closest primate cousins, chimpanzees and gorillas.

This comparison would be expected to reflect how our lives diverged over the millenniums, said Daniel Lieberman, an evolutionary biologist at Harvard and one of the study's principal co-authors.

Other others were the Harvard cardiologist Dr. Aaron Baggish and the exercise physiologist Robert Shave, from the University of British Colombia's Okanagan Campus.

Hearts, however, ''do not fossilize,'' Dr. Liberman said, so the best way to learn about their evolution would not be through excavations but via comparative appraisals of our organs with those of our erstwhile relatives.

The honor and serving of the latest operational research on Evolution and Humans, continues. The World Students Society thanks author Gretechen Reynolds.