A Powerful Organ Hearts, eyes, flippers and wings — evolution has forged many remarkable body structures. But none is more amazing than the brain, that bundle of nerve cells that allows us to sense our surroundings, sort out information, and make decisions. Indeed, the great importance of BRAIN POWER to evolution is the subject of this week’s installment of NATURE’s TRIUMPH OF LIFE series.
Brains are not essential to life. Many organisms, from algae to jellyfish, get along just fine without a central information-processing center. But there is no question that a brain gives many animals an edge. For in the struggle for survival, brawn often gives way to a brain that can outthink a competitor.
Not all brains are equal, however. Some brains consist of just a few hundred or few thousand cells, just enough to sense changes in light or temperature, or to sniff out important smells. Others, like ours, contain billions of cells, enabling everything from language to tool-making.
But simple is often more than enough to assure an animal’s survival. A flatworm’s basic brain, for instance, helps it sniff out earthworms, making the worm a lethal hunter. And while a honeybee’s brain is bigger than a flatworm’s, it is still not all that complex. Nonetheless, the bee is capable of amazing feats of memory, as BRAIN POWER shows.
In their short two-month lives, worker bees must learn to remember where nectar-producing flowers are located in relation to the hive, and exactly what time of day they produce the sweet liquid. The life-or-death memorization is aided by an amazing change in the bee’s brain: as it needs to retain more information, the brain grows, adding tens of thousands of cells on an as-needed basis! Once, scientists believed that such brain-changing abilities were limited to just a few animals. In recent years, however, evidence has shown that many animals’ brains are more flexible than once thought possible. Some birds, for instance, grow new brain tissue during the breeding season — perhaps to sing more complex songs — then lose the cells once mating is over. Other bird brains grow or shrink for migration.
Produced by: David Heeley & Suzanne Weinert
Title: Triumph Of Life-Brain Power
File Size: 742 MB
Video Length: 00:52:51
Video Codec: XviD
Video Resolution: 720x384
VIdeo Bitrate: 1918 kbit/s
Audio Bitrate: 192 kbit/s
Audio Codec: (AC3)
Subtitles: (External English)