Death Match

Lash nodded. “The desire to send your genes on to future generations under the best possible conditions. A fundamental impulse.”

“Precisely. And the ‘best possible conditions’ usually means a high degree of genetic variability. What a technician might call an increase of heterozygosity. It helps ensure strong, healthy progeny. If one mate is blood type A, with a relatively high susceptibility to cholera, and the other mate is blood type B, with a heightened susceptibility to typhus, their child — with blood type AB — is likely to have a high resistance to both diseases.”

“But what does this have to do with what’s going on in there?”

“We keep very close tabs on the latest research in molecular biology. And we’re currently monitoring several dozen genes that influence the choice of an ideal mate.”

Lash shook his head. “You surprise me.”

“I’m no expert, Dr. Lash. But I can offer one example: HLA.”

“I’m not familiar with it.”

“Human leukocyte antigen. In animals it’s known as MHC. It’s a large gene that lives on the long arm of chromosome 6, and affects body odor preferences. Studies have shown that people are most attracted to mates whose HLA haplotypes were least like their own.”

“Guess I should be reading Nature more carefully. Wonder how they demonstrated that?”

“Well, in one test, they asked a control group to sniff the armpits of T-shirts worn by the opposite sex, and to rank them in order of attractiveness. And the scents the group universally preferred were of people whose genotypes were most different from their own.”

“You’re kidding.”

“No, I’m not. Animals also display this preference for mating with partners whose MHC genes are opposite their own. Mice, for example, make the determination by sniffing the urine of potential mates.”

This was greeted by a brief silence.

“Personally, I prefer the T-shirt,” Tara said.

It was the first time in several minutes that she’d spoken, and Lash turned to look at her. But she wasn’t smiling, and he was uncertain whether she’d meant it as a joke.

Mauchly shrugged. “In any case, the genetic preferences of the Wilners and the Thorpes would be pooled with the other information we’d gathered on them: monitoring data, test results, the rest.”

Lash stared at the gowned workers on the far side of the glass. “This is amazing. And I’ll want to see those test results in due time. But the real question is how, exactly, did the two couples get together?”

“That’s our next stop.” And Mauchly led the way back into the hallway.

A confusing journey through intersecting corridors; another brief ascent in an elevator; and then Lash found himself before another set of doors labeled simply: PROVING CHAMBER.

“What is this place?” Lash asked.

“The Tank,” Mauchly replied. “After you, please.”

Lash stepped into a room that was large, but whose low ceiling and indirect light gave it a strangely intimate atmosphere. The walls to the left and right were covered with various displays and instrumentation. But Lash’s attention was drawn to the rear wall, which was completely dominated by what seemed some kind of aquarium. He paused.

“Go ahead,” Mauchly said. “Take a look.”

As Lash drew closer, he realized he was looking at a vast translucent cube, set into the wall of the chamber. A handful of technicians stood before it, some scribbling notes into palmtop computers, others simply observing. Inside the cube, i

“You understand why we call it the Tank,” Mauchly said.

Lash nodded absently. It was an aquarium, of sorts: an electromechanical aquarium. And yet “Tank” seemed too prosaic a name for something with such an otherworldly beauty.

“What is this?” Lash asked in a low voice.

“This is a graphic representation of the actual matching process, occurring in real time. It provides us with visual cues that would be much harder to analyze if we were sca

“Avatar?”

“The personality constructs of our applicants. Derived from their evaluations and our surveillance data. But Tara can explain it better than I.”

So far, Tara had stayed in the background. Now, she came forward. “We’ve taken the concept of data mining and analytics and stood it on its head. Once the monitoring period is over, our computers take the raw applicant data — half a terabyte of information — and create the construct we call the avatar. It’s then placed in an artificial environment and allowed to interact with the other avatars.”

Lash’s gaze was still locked on the Tank. “Interact,” he repeated.

“It’s easiest to think of them as extremely dense packets of data, given artificial life and set free in virtual space.”

It was strange, almost u

“It’s beautiful,” he said. “But bizarre.”

Abruptly, the faraway look left her eyes. “Bizarre? It’s brilliant. The avatars contain far too much data to be compared by conventional computing algorithms. Our solution was to give them artificial life, let them make the comparisons on their own. They’re inserted into the virtual space, and then excited, much in the way atoms can be. This prompts the avatars to move and interact. We call these interactions ‘contacts.’ If the two avatars have already intersected in the Tank, it’s a stale contact. But if this is the first encounter between two avatars, it’s a ‘fresh contact.’ Each fresh contact releases a huge burst of data, which basically details the points of commonality between the two.”

“So what we’re looking at right now are all of Eden’s current applicants.”

“That’s correct.”

“How many are there?”

“It varies, but at any one time there could be up to ten thousand avatars. More are added constantly. There could be almost anybody in there. Presidents, rock stars, poets. The only people…” she hesitated. “The only people not allowed are Eden perso

“Why’s that?”

Tara’s reply did not address this question. “It takes approximately eighteen hours for any one avatar to make contact with all the others in the Tank. We call that a cycle. Thousands upon thousands of avatars intersecting with every other, releasing a massive torrent of data — you can imagine the kind of computing horsepower required to parse the data.”

Lash nodded. There was a low beeping behind him, and he turned to see Mauchly raising a cell phone to his ear.

“Anyway,” Tara went on, “when a match is determined, the two avatars are removed from the Tank. Nine times out of ten, a match is made within the first cycle. If there is no match, the avatar is retained in the Tank for another cycle, then another. If an avatar hasn’t found a match within five cycles, it’s removed and the candidate’s application is voided. But that’s only happened half a dozen times.”

Half a dozen times, Lash thought to himself. He glanced over at Mauchly, but he was still on the phone.

“But under normal circumstances, you could take one of these avatars, put it back in the Tank a year from now, and another match would be found. A different match. Right?”