Dave Freedman - Natural Selection

The same basic process had led to the evolution of every organ in every animal ever known. While the variations among ancestral giraffe populations resulted in the selection of long necks, similar variations among other species in other environments led to completely different adaptations: the tiger’s fanged mouth, the elephant’s long trunk, the cougar’s powerful legs. They’d all evolved out of necessity, to help a given species survive in its particular environment, and each variation demonstrated the unambiguous power of natural selection.

Jason stuck his index finger into the tray and ran it along the brain’s eighteen-inch-long surface.

“So why did this brain evolve flat?”

“Good question. The short answer is to make these rays of yours hard to kill.”

“ A flat brain makes them hard to kill?”

“Yes,” the doctor said matter-of-factly, leaning back on his sofa. “That’s a pro. But there are cons. The major one is that the brain itself is less efficient than it would be if it were rounded. You see, with a flat brain, there are fewer synapses”—connections—“between brain cells, which makes the brain work harder to process the same amount of information.”

The human brain contained 14 billion cells and trillions of connecting synapses. A spherical shape was the most efficient at supporting such a complex network because it allowed multiple connections.

“I’m not saying this animal is stupid, mind you. No, far from it. Not with a brain this big. Even flat, this animal is still very smart. It’s just not as smart as it could be.”

“Thank God for that.” Jason was beginning to wonder if he actually wanted to find one of the rays alive. “And what makes it hard to kill?”

“Three factors. First, the cerebral cortex is spread over a large surface area and is far less susceptible to damage than normal. Second, like the brains of many predators, the pain center here is tiny; actually this one borders on nonexistent.” The pain center is what informs an animal when it is hurt, and in effect, tells it to slow down and take care of itself. “Humans have very large pain centers. If we get the slightest pinprick, we know something’s wrong. But this animal effectively doesn’t feel pain at all and it won’t slow down for anything. It will literally do whatever comes naturally to it right up until it dies. And in the case of a predator, that means hunting.

“Third, this brain has what I call spread sensory systems. Spread sensory systems exist to a limited extent in all brains, but they are here in abundance.”

“Spread sensory systems.” Jason had never heard the term before.

“Yes. I suppose you could think of them as the neurological equivalent of emergency generators. They provide the brain with a series of ‘support cells’ that effectively act as backups for every function in the body. It is these backups that make this animal hard to kill. All brains, this one included, have specialized cortexes—motor, visual, auditory, et cetera, et cetera. These cortexes act as control centers for particular body functions. So normally, when a given cortex is damaged, the body function it supports ceases operating and the whole body dies.

“For example, if a person were shot in the head, and the breathing cortex was damaged, all the body’s respiratory functions would immediately stop—even if the respiratory organs themselves were entirely functional. And even if the breathing cortex weren’t damaged, if the bullet entered here”—he pointed at a spot on his own head—“it would rip through the left and right frontal lobes, the parietal, the occipital, the temporal regions; it would rip through bloody everything, and do critical damage to other important cortexes. By the time it was done, the heart, the immune system, and every other function the body needed to live would instantaneously stop and the body would die.”

Jason nodded. “OK.”

“But”—Vishakeratne held up a finger—“with a brain that has spread sensory systems and is flat, a single bullet would not irreparably damage any individual control center. The destruction would be far, far less.”

Jason’s brow crinkled up tensely—he couldn’t believe what he was hearing. “How much less? How many ‘backups’ are there?” Two or three, he imagined.

“Oh, I don’t know exactly.” The neurologist huffed. “I’d imagine… thousands.”

“ Thousands? Are you saying it would take thousands of bullets to kill one of these animals?”

“No, I’m not saying that.”

“What are you saying?”

“Look.” Veesh shaped his fingers into a gun and aimed the “barrel” at the brain in the tray. “I’m saying if I placed a gun right here and fired, this animal wouldn’t die. A small part of one cortex would be slightly damaged, but the bulk of the brain, and the bulk of the animal’s body functions, would continue to operate normally. I doubt if it would even be seriously wounded.”

Jason almost laughed. “Are you saying it’s indestructible? That it can take an infinite number of bullets?”

“No, of course not. I have no idea how many bullets it could take, just that it would be more than a few. Surviving a bullet to the head isn’t nearly as uncommon as you might think. I’ve seen Tanzanian bobcats take four or five and survive.”

Decades earlier, Vishakeratne had performed an extensive twenty-two-week study on the famously bullet-tolerant predators. In a well-known report, he linked their phenomenal ability to survive “severe head and brain injuries caused by gunshots” to what he dubbed “unusually shaped cerebral cortexes that have a tendency to be flat.”

“Something else is significant here. This is a mature brain.”

“As opposed to immature?”

“Precisely. A brain’s maturity refers to its evolutionary age. And this brain has been around for a very long time. Humans actually have an immature brain, only four million years old, which, compared with the developmental period of other large brains—the dolphin’s, whale’s—is shorter than a twenty-four-hour flu.”

Vishakeratne carefully lifted the entire brain out of the water with his bare hands, little drops falling onto the glass. “You see, there are no cavity suppressions here.”

Unlike mature brains, immature brains show evidence of having been compressed, as if they’d been squeezed into a container too small for them. Cavity suppressions, which are small dents in a brain’s surface, appear when a brain literally outgrows the skull it is encased in. The human brain, for example, has evolved so quickly that it often folds on top of itself and actually appears squashed when it is removed from a skull.

The scientist returned the gray mass to the water. “This is a very mature brain, and that fact is not trivial. It indicates these rays have been fully functional predators for much longer than man has even been alive. I know you must be very anxious to find one of these animals, and I wish you luck in doing that, but I can’t emphasize this point enough. These rays know how to hunt; they know how to kill. Believe me, in any confrontation, they’ll know more about you than you know about them. So if you do find one, you should be very, very careful with it.”

Andrea’s voice rang out from an intercom. “Dr. Vishakeratne, your staff meeting is in fifteen minutes.”

“Oh.” The man checked a $6,000 Rolex. Fifteen minutes indeed. Despite his stature, Vishakeratne insisted on attending monthly staff meetings. “You’re going to have to excuse me now.” He stood. “But stay on top of this, and please keep me abreast of what happens.”

Jason quickly rose from his sofa. “I will. If it’s not too much trouble, would you mind e-mailing me your findings?” He handed him his card.