Looking to the Sea for Answers

If you had a family album stretching back to the dawn of animal life on Earth, you’d find the first picture to be of a sponge. Not the square sponge carcass found in bathrooms, but something more like the sponges living in today’s oceans. At least, that is what the evolution of evolutionary theory has determined.

A new PBS series, “The Shape of Life,” presents this finding and other revelations about evolution in an intelligent and highly watchable format. Though the science itself is remarkable on its own, the documentary keeps the action focused through spectacular underwater photography, nicely used computer animation and a generally tight script.

In the first of the two hourlong installments being shown tonight, “The Shape of Life” begins with a longish introduction full of a lot of unanswered questions; don’t let that turn you off. Soon enough, the scene shifts to Sulawesi Island in Indonesia, where UC Santa Cruz biologist Christina Diaz is researching the surprisingly complex structure of sponges.

“I think they are beautiful, they are original, they are mysterious,” Diaz says. “They have lots of secrets that we have to unveil.”

Interestingly, it was the sponge’s apparent physical simplicity that initially led scientists to suspect it to be the first animal. But it wasn’t until recent advances in the reading of genetic blueprints that Mitch Sogin, director of the program in molecular evolution at Woods Hole Marine Biological Laboratory in Massachusetts, found the most definitive evidence yet of the sponge as the foundation of the animal kingdom.

“The Shape of Life” continues tonight with Part 2, which examines how animals began to move. Later episodes center on, among other things, the first hunters, the emergence of life on land and how these weird and fantastic creatures we’ve seen relate to human development.

Though creationists may have a difficult time with this series, it is well worth seeing, no matter what one’s beliefs.

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“The Shape of Life” premieres tonight at 9 on KCET, followed by Part 2 at 10 p.m. Subsequent episodes will air April 9 and 16, and May 19 and 26.