Geobiologist Victoria Orphan stands at the stern of the research vessel Western Flyer, watching her colleagues put the last touches on an unusual spread. Among the offerings: a large turkey leg, an alligator head and bowls of gelatinous agar that resemble consommé.

This meal isn’t for the ship’s crew. It’s bait.

The entrees are anchored to a plastic grid and pushed overboard so they will sink into the deepest underwater canyon along North America’s West Coast.

The scientists check the attached camera, which will spy on the creatures that show up to feast — fish, worms, crabs and microbes too.

The microbial denizens of Monterey Canyon are far different from many of their surface-dwelling brethren. They make food out of rocks and dead debris and harvest energy from methane that seeps from the ocean floor. To survive in this dark, high-pressure, low-oxygen, low-nutrient environment, they form all kinds of cooperative relationships.

Orphan’s study of these “extremophiles” may offer insights about the evolution of life on Earth — and guide the search for life on other planets. Her work earned her a MacArthur Fellowship, also known as a genius grant.

Much of her research takes place at Caltech, where she runs a lab with dozens of graduate students and postdoctoral researchers.

Orphan is co-leading this trip with Shana Goffredi, a biologist at Occidental College who is also her life partner. Where Orphan studies microbial alliances, Goffredi explores the relationships between microbes and larger animals such as clams or snails.

Alligator heads and turkey legs are small fry for this crew. About a decade ago, Goffredi and other scientists at the Monterey Bay Aquarium Research Institute towed the carcasses of dead whales out to the canyon and released them at different depths. The result was an enormous experiment that shed light on the complex population dynamics of these deep-sea communities.

Just as wildflowers blossom in the barren desert after a storm, long-dormant microbes bloom on a “whalefall” as they feast on the carcass alongside crabs, clams and fish. The microbes produce chemicals that other microbes can put to use. The result is a community whose demographics shift dramatically over time depending on the depth and pressure of the ocean.

Orphan and Goffredi visit these whalefalls two or three times per year, sampling the water, wildlife and sediments to discover if something has changed.

“Almost every time, we find a new species,” Goffredi said. “And that’s just the animals.” The microbes, she added, are guaranteed to produce something that’s never been seen before.

When Orphan gets her microbes back to Caltech, she hopes to set up a tiny deep-sea ecosystem in her lab. Then she could see how they interact with one another in different situations.

The geobiologist’s enthusiasm for her marine microbes knows no limits. She’s gathered a lot of samples this time, and her team rushes to process them. “My eyes are bigger than my minus-80 freezer,” she said.