Wired

Kira nodded as the waiter appeared again with their bill. Desh paid him immediately with cash, including the tip, so he wouldn’t have reason to disturb them further.

Kira waited for him to leave and then resumed the discussion. “I had achieved my first goal, a further leap in intelligence, but was afraid to use it. About fourteen months after I was robbed I achieved a breakthrough on my second goal. Smith was accurate. I can double the span of human life.”

“How?” asked Desh, not wanting to have the conversation bog down but unable to repress his curiosity. “Just give me the Cliffs Notes version.”

Kira paused, as if considering how best to frame her response. “As I said before, our brains aren’t optimized for thought. Well, not surprisingly, our bodies aren’t optimized for longevity either. Again, all natural selection cares about is reproduction.” She took a sip of iced-tea and set it back down on the table. “If you have a mutation that enhances your ability to survive to childbearing age, this mutation will preferentially appear in future generations. But longevity genes don’t kick in until you’ve already done all the reproducing you’re ever going to do. The guy who dies at forty has just as much chance of having scores of children, and passing on his poor longevity genes, as the guy who dies at eighty has of passing on his good ones. There’s no evolutionary advantage to long life.”

Desh’s eyes narrowed. “But parents who live longer can increase their offspring’s chances of survival. So longevity genes should confer an advantage.”

“Very good,” she said. “This is true. There is evolutionary pressure on our genes to keep us alive long enough to ensure our children can take care of themselves. But after this point there’s no advantage to further longevity. In fact, there might even be evolutionary pressure against it.”

Desh looked confused.

“The elderly can be a burden on the clan when resources are scarce,” explained Kira. “Decreasing the chances of survival for future generations.”

A look of distaste came over Desh’s face. “So those clans whose elders have the decency to drop-dead early on and not drain further resources thrive more than those whose elders live forever?”

“During times of scarcity at least, yes. This is one probable explanation for why most life on Earth, including ours, is programmed to die.”

Desh’s brow furrowed in confusion. “What does that mean?” he said “I thought aging was the result of errors accumulating in our DNA.”

“Partially true. But a large part of aging is due to a form of planned obsolescence. Our immune systems weaken, we stop producing hormones like estrogen, our hair grays or falls out, our skin shrivels, the acuity of our hearing diminishes, and so on. Our bodies are programmed, at the level of our genes, to die.”

“You’re the scientist, but it’s hard for me to believe that’s true.”

“That’s because it happens gradually,” she said. “In some species, like pacific salmon and marsupial mice, it happens all at once. One day they have no signs whatsoever of aging and the next—bam—they’re dead from old age.” She paused. “Other species aren’t programmed to die at all, like rockfish and certain social insect queens.”

Desh tilted his head. “But they do die, right?”

“They die. They just don’t age as we know it. Eventually accidents or predators or starvation kills them.”

Desh had further questions but knew that now was not the time. “Go on,” he said.

“I studied these species extensively to understand why they didn’t age. I also took DNA samples from people who suffer from a rare aging disease called progeria. By the age of twelve progerics look and sound like elderly people.”

Desh shook his head sympathetically. “I’ve heard about that. What a horrible disease.” He paused. “Can I at least assume their DNA was illuminating?”

“Very. It led directly to the breakthrough I needed,” she said. “I had been studying everything I could find on the molecular basis of aging for years. But when I added data on the genetic differences between progeria victims and normals my optimized brain was able to put all the pieces together.”

“And you’re positive your treatment will work? That it really will double the span of human life?”

“Absolutely certain,” she said without hesitation. “One hundred percent.”

Desh had become stiff from his angled position in the booth as he continued to watch the entrance, and he shifted temporarily into a more comfortable position. “How can you be so sure?” he asked, rubbing the back of his neck with his left hand while continuing to grip the gun with his right.

“There are a number of ways,” replied Kira. “But you’d need a much deeper knowledge of molecular biology and medicine to understand most of them. One way is to look at cellular doubling times. Most people don’t know this, but most of your cells will only divide about fifty times in culture. This is called the Hayflick limit. As they approach fifty doublings they take longer and longer to divide and show signs of aging.”

“What happens after they divide fifty times?” asked Desh.

“They die,” she said simply.

Desh pondered this for a few seconds. “What about cancer cells?” he asked.

“Good question. Cancer cells are the exception. They’re the immortals among cells. Not only will they go beyond fifty doublings, they’ll continue doubling forever. It’s this unconstrained growth that eventually makes them deadly to their host.”

Desh was fascinated by all of this but he was out of his league and knew he needed to move on. “Let’s say I believe your longevity therapy works the way you say it does,” he began. “Let’s say I even believe you aren’t involved in bioterror. But here’s the question: if you really did discover the fountain of youth, why have you kept it a secret?”

Kira raised her eyebrows. “Because I didn’t want to be responsible for knocking humanity back to the Dark Ages,” she said simply.

28

David Desh spotted their waiter and motioned him over. They were in a dark, comfortable little corner of the vast mall and his fear of being discovered was waning by the minute. They had time before they had to catch the bus and he was in no hurry to leave.

“Can you start a new check for us?” asked Desh when the waiter arrived.

“Sure, what can I get for you?”

Desh quickly leafed through the menu. “We’ll both have hot fudge sundaes.”

The man nodded and hurried off.

“Hot fudge sundaes?” said Kira.

“I want an excuse to stay here longer,” he explained. He allowed himself to smile. “Besides, when I’m talking to you my brain needs all the glucose it can get.”

She looked almost bashful. “Sorry to have to throw so much at you at once. I know it’s like drinking from a fire-hose.”

Desh grinned at this. “Not at all. Once again you have me intrigued,” he said. “So please go on.”

“Smith told you his theory as to why I’ve kept longevity a secret,” she said. “To acquire great power and wealth.” She shook her head in disgust. “Nothing could be further from the truth. I’d love to share the treatment. The problem is, when I was still enhanced, I considered what the world would be like once I did. The conclusions I reached were shocking.”

Desh tried to guess where she was heading, but couldn’t.

“If everyone lives to be 150,” continued Kira, “what happens to the world’s population?”

For a moment Desh wondered if it was a trick question. He shrugged. “It would go up,” he said.

“It would go up,” she repeated. “A lot. At least as many people would be born each year but far fewer would die. And women would be at reproductive age twice as long. The planet is already overcrowded and getting steadily worse. Introduce my therapy and everyone would need to make room for their great, great, great grandparents.” She shook her head emphatically. “Doubling the span of human life would be an absolute disaster.”

“It’s true our society would have to make changes,” acknowledged Desh, “but you can’t be sure the effects would be catastrophic.”

“Overpopulation doesn’t just have physical effects, it has psychological effects as well,” she said. “A