The Great Rift of East Africa is a fascinating region. It is one terminus of a system of plate tectonics—that is, drifting continents—that traverses the globe of Earth. Our world seems to be boiling like a slow pot of mush, with hot lava welling up along a series of fault lines, pushing the existing surfaces apart, and in the process moving the continents around like ungainly checkers. If we trace that line of fire, we find it circles Africa clockwise, splitting in the Indian Ocean to send one rift looping around the Pacific Ocean, forming the “Ring of Fire” there and touching America to form the San Andreas Fault. Meanwhile the other fork proceeds from the Indian Ocean to complete its circuit of Africa, moving north to form the Mid-Atlantic Ridge, passing the North Pole, entering Siberia at the Lena River Delta, tunneling under until it surfaces again at Lake Baikal, then carries across Asia to Turkey and the Mediterranean Sea, where it plunges down through the Red Sea, and finally ties back into Africa at the Great Rift where it started. There has always been a whole lot happening along this fire line, and it may also account for mankind’s emergence as the dominant species of the planet.
In Africa itself, the Rift proceeds roughly south from the point where the corner of Arabia almost touches it—that point being known as the Afar Triangle—through modern Ethiopia, Kenya, Uganda, Tanzania, Zaire, Zambia, and Mozambique. In simpler terms, it is a thirty-five-hundred-mile system slicing off the eastern segment of the continent. About halfway along, it divides into two branches, forming a great crude circle that encloses Lake Victoria. Geologists don’t seem to know why it divides, but the answer seems obvious to the uninformed: this is the site of a meteor strike that tore up the landscape so badly that the Rift itself was fractured and had to detour around, leaving the crater to fill with refuse and water and form the lake. Something similar evidently happened at Iceland, which lies astride the Mid-Atlantic segment of the fire line.
This is rough country, with Africa’s highest point—Mt. Kilimanjaro—and lowest point—in the Afar Triangle—both associated with the Rift. It is bounded by the great Sahara Desert in the north and the jungle of the Congo in the south. Within the Rift there is constant volcanic activity; its inlet in the Afar Triangle, lined with volcanic cones, is called “The Devil’s Throat,” and its low Danakil Depression has been described as the “Hell-Hole of Creation.” Lions, hyenas, elephants, and the Cape buffalo range the Serengeti Plain southeast of Lake Victoria. Lake Malawi at its southern extreme has more fish species than any other lake in the world. What kind of primate would leave the protection of the jungle and choose to live here? Perhaps only one who was desperate, and hungry, and smart enough to survive its hazards. As it turned out, mankind.
But not quite yet. The time is approximately eight million years ago, and the place is central Africa near the Equator, on the eastern slope of the western branch of the Rift. Today the remnant of the mountain gorilla lives there, and it is part of the much wider range of the more versatile chimpanzee. But back then the two species were diverging from a common ape ancestor, and the smaller, thinner cousin—the “gracile” one—had to give way to the “robust” one. This led in some cases to a forced extension of the range. Most chimps were displaced westward; one band went where none other had dared, east over the volcanic ridge. This was not bravery but the luck of the draw; they couldn’t get around the gorillas, so had to retreat where they would not be pursued. The immediate outlook was not promising.
* * *
Hu lifted on his hind legs and gazed at trees on the slope below. The brutes were there, making threatening gestures. The trees of home had been occupied by stronger foreigners.
“Come!” Hu recognized his mother’s urgent call. He dropped to four feet, turned, and scampered up the slope to join her. His little sister Be was doing the same.
They had foraged often on this slope, finding bugs and berries and caches of water in crevices. Hu was well familiar with it. But there were times when the mountain trembled and smoke spouted from its mouth, frightening them away. Now they were going toward that mouth. That wasn’t safe, for no one could know when it might spout again.
But there was nowhere else to go, because of the brutes below. Hu’s father, the dominant male, had tried to hold his territory, but the brutes were just too big. So he and several other males were taking their families away, seeking some better place. They had to move out before the brutes came after them, to take their women and kill their children. Hu had seen what happened to a neighboring band whose male had fought and lost. They all had seen. The women were not actually used by the brutes, but became tolerated outcasts, allowed to feed themselves until a brute female or adolescent male became annoyed and attacked. So the end was the same for the spared women; it just took more time, because they weren’t deemed to be threats.
Hu and Be scrambled after their mother, just as the other children were after their mothers. She was no larger than Hu himself, but she ruled him until he chose to leave the family. Near them were Ra and Fa, following their mother. They were children of Hu’s father, because the dominant male mated with all the women in the band. That made them close kin; they had the kin smell. Hu got along well with them, and they often groomed each other, picking out the bugs in their fur. When there was any alarm, and the mothers weren’t close by, Hu and Be usually grouped with Ra and Fa.
The climb went on and on. The mountain trembled almost continuously, but they were getting used to that. They could tell when the mountain was feeling angry, and right now it was merely irritable.
As the day waned, they got beyond familiar territory. The group closed in together, becoming nervous; none of them liked strange land. There were too many dangers in the unknown.
But they were lucky, or perhaps the big males had been here long ago and knew where to look. There was a cave. It wasn’t deep, but it was big enough to shelter the bands. There were several recesses, and one male took over each recess, putting his mates and children there. They would be safe here. It wasn’t as good as a tree, but it was better than the open slope. Especially since the mountain was rumbling louder now, with smoke rising from its top, and some rocks were shaking loose and sliding down the steeper slopes. There was a pile of rocks before the cave, but not many inside. They would be good to heave at predators.
There were berry patches nearby, growing in furrows and gullies in the slope. They were rich with ripe berries because no one had been this far to pick them before. Immediately the women and children went out to eat. Hu dashed for the nearest patch, but a male growled him off. He had to go farther out. This was happening more as he got older; the big males were starting to notice him, and not with favor.
He moved on out. There was a cry, and Be was scampering after him. Hu was disgusted; she would slow him. She had been weaned only the year before. But she was his little sister, close kin, and he had to accept her. So he waited for her to catch up, and then they went on together.
Other young folk were spreading out, seeking untouched berry patches in the hollows of the slope. Those who first spied a good patch stood guard over it, reserving it for their own siblings. Hu didn’t want to fight; he was already tired from the long climb. So he went on beyond, Be beside him.
Be was agile enough. She scampered up a steep ridge to a crevice above—and paused, with an exclamation of awe.
Hu knew that she didn’t make that sound for nothing. Young as she was, she was learning the key danger sounds, and would not utter them randomly. But this was not quite danger; it was more like mystery. So he had to investigate. It might be something she didn’t know was dangerous.
He mounted the ridge, grabbing handholds and hauling himself up. He reached her side, and followed her gaze ahead.
It was indeed different. Beside the ridge was a deep crevice, and from it warm air gusted. He squinted, peering into it. There was light in there, like that of the sun on a dim day. There was an odd sound, not quite like water running, and a strange hot smell. Hu did not understand this, and for that reason he did not like it.
But before he could warn Be away, she spied something new. Beyond the crevice was a fine patch with many large ripe berries. She bounded over the crevice and began to pick them, greedily eating.
Hu hesitated. That burning light in the crevice—could it hurt them? He wanted to know more about it before trusting it. Besides, he was curious. His curiosity had on occasion gotten him in trouble, such as when he had ventured too close to a copulating couple and put his nose in the way, but it had also enabled him to discover interesting things. So he had two reasons to explore this situation.
He followed the cleft, sniffing the fumes. It led down the slope, seeming to be a crack in the mountain, like an open cut. Was he seeing past the mountain’s skin to the blood inside? Did the mountain hurt? Was that why it was rumbling? He knew how a deep cut could sting. But what could have made such a cut in so big a hill? No lion could have done it, and no elephant either.
There was a cry. That was Be’s distress call. Hu spun around and leaped back toward the berry patch. What mischief had she gotten into?
He saw a larger form by the patch. It was Ss, the nasty child of one of the other dominant males, a year younger than Hu. He had never gotten along with her or her brother Bb, because they were always doing something mean.
Ss didn’t see Hu. She was stalking Be, trying to drive her away from the berry patch. Naturally Ss wanted all the berries for herself. As Hu loped toward them, he saw Ss pounce on Be and lift the child into the air. Be struggled, terrified. Ss carried her to the deep crevice, about to throw her in. Be screamed, her arms and legs flailing helplessly.
Then Hu reached them. He snatched Be away, hugging her, keeping her safe. Ss screamed with frustration. She seemed about to attack Hu, but she was smaller as well as female, so could not win.
There was a sound behind Hue He turned cautiously, so as not to leave Ss at his back, and saw her brother Bb advancing on them. Bb was Hu’s age, but larger; he could win a fight. Hu and Be would have to give up their berry patch and flee, because they could not match the nasty pair. It was too bad, because the patch was theirs; latecomers were supposed to honor the choices of the early comers. Hu was hungry; he realized he should have started eating immediately, instead of getting distracted by the curious crevice.
But then two more figures appeared. Ra and Fa! They were kin and friends. They were a year younger than Ss, but both could fight well. Now the kin were more than the foreign ones, and they would be able to hold the patch.
Hu called, and Ra and Fa immediately scrambled up the slope to join them. Then the three of them stood before Bb and Ss, snarling, keeping little Be behind them.
Bb snarled in return, threatening to fight. But when Hu advanced, he retreated. He never liked to fight when he wasn’t sure of winning, and he couldn’t win against two males; even if neither was quite his size. Fa, though a year younger than Ss, could nevertheless prevent her from helping her brother fight. So Bb retreated, and Ss retreated with him. In a moment they turned and ran away.
Hu, Ra, and Fa smiled at each other. Then they settled down with Be to eat the berries. The little fruits were wonderful. The funny thing was that Hu used one forefoot to pick most of his berries, while the other three used the other forefoot. But all of them could use either foot, when they thought about it, so it didn’t matter.
In due course the four made their way back across the hot crevice and down the slope to the cave. Their mothers were waiting for them. It was good to be home, even if it wasn’t much like their trees.
* * *
Next day they moved on up the slope, foraging as they went. The mountain was rumbling less, but they were getting closer to the smoke. Hu saw the others cringe as clouds of the smoke came out and spread toward the group. They were afraid of anything strange. Hu, in contrast, was attracted to oddities, and the more dangerous they seemed, the more he wanted to know about them. His curiosity warred with his fear, sometimes leaving him standing bemused, unable either to advance or to retreat. He was especially sensitive to sounds; they fascinated him, and odd ones could lure him beyond safety. He seemed to hear qualities of sounds that others ignored, so had given up on getting any support for this interest. The sounds of the fire mountain had power and resonance unlike others, as if a giant lion struggled within.
But smoke had never actually harmed him or anyone he knew before. It came from fire, and fire was hot and hurtful but could be avoided because it burned only on the grassy vallley below their forest. And, perhaps, inside the mountain. So Hu wanted to know more about smoke, and was glad to be approaching it.
However, the leaders were wary, and when the slope allowed it, they moved around to the side of the mountain. There were more bugs and berries there, and it did seem safer.
But then they entered a high sort of valley between this mountain and the next. The slope above was steep and bare and hot in the sun; the slope below became a narrowing crevice. There was a bad smell that made them cough and choke.
They paused, milling. There did not seem to be anywhere to go forward. But there weren’t enough berries this high to sustain them, and behind were the brutes.
Hu, as curious as ever, decided to explore the crevice. Be scampered after him, thinking he knew where he was going. He would not have signaled it, but he found her company reassuring. He could not take any bad risks when she was with him, because he had to protect her. That made it safer for him, too.
When the slope got too hot and steep, they moved down into the crevice. It was wider than it had looked from above, but scary too, because its walls were very high and close together. There was just room to walk at the base. But Hu saw that up ahead the walls became so bare that it would not be possible to climb them. If anything rolled down, he and Be would be crushed. Indeed, there was a pile of stones there that they had to climb over.
They stood on the top of the pile and looked on into the crevice. Wisps of vapor floated up from vents in the ground, and there was a faint but ominous hissing. The smell was bad. This was far enough to go.
Be tugged at his hand. She was frightened, and wanted to go back. That was a good enough pretext. So Hu shrugged and turned, pretending to humor her.
There was activity behind them. Someone else was following. At first Hu was glad, because he thought he could show off what he had found. Then he recognized Bb and Ss.
This was a problem, because he knew they meant mischief. They were still mad because they hadn’t gotten the berry patch yesterday. Now they wanted to fight, and there was no grown kin to support Hu. What was he to do?
The sensible course was to run away. But they were blocking off the only escape. The walls did not seem any more scalable than before; only the bottom of the crevice was suitable. Bb knew that. He knew he had Hu trapped. He knew that no one else was close enough to intercede.
Hu turned again and looked forward. The crevice looked as forbidding as before. The evil vapor swirled in it, so that Hu could not see what was beyond. The hissing seemed louder now, like that of a restive snake. That was no place for a person to go.
There was a sound behind as Bb and Ss advanced. Normally females fought only among themselves, or to protect their children, but Ss often fought to support her brother. She was aggressive and vicious. Like her brother. Hu had little chance against Bb in a fair fight, and with Ss chomping his back, he had even less. She was really worse than Bb, because she was not being true to the nature of her gender.
Hu turned once more. He peered down through the steaming crevice. That might be doom—but so might a fight with Bb. He couldn’t afford to get beaten, when he had Be to protect.
Bb was getting close. He leaped to the base of the rock pile. Hu leaped off it, into the crevice ahead. He called to Be to follow. This seemed to be the lesser risk, and now that he had made the decision, he felt his curiosity about what lay ahead. He had wanted to explore farther, but hadn’t dared. Now there was as much of a threat behind as ahead, so it was easier to go on.
Be scampered close behind him. She was afraid too, but trusted Hu to keep her safe.
They came to the first vapor vent, and plunged through it. The air was hot but they weren’t in it long, so it didn’t hurt. But there was another vent beyond, with thicker steam.
Hu halted. Be stopped so close she was nudging him. He looked back. The prior steam masked the cleft beyond it. He couldn’t see whether Bb was coming after them. But Bb couldn’t see Hu and Be either. Would he come? Maybe he would just wait until they returned, then pounce.
Hu thought of the rocks that might roll down from above. He didn’t want to wait here long. So he moved forward again, Be nervously pacing him.
He paused before the steam. The odor was bad, but it wasn’t making him choke. The hissing was steady rather than menacing. Maybe it was safe. Should he try to leap through it? He saw some of the path beyond, and it looked all right.
There was a sound behind. Hu leaped through the steam. He landed safely beyond it, with Be almost underfoot.
The way ahead was narrower than ever, and it curved. But Hu was recovering confidence. This path was not as deadly as it had seemed. Where did it go?
They moved on, passed through one more steam vent, and then the crevice got wider. The two mountains pulled away from each other and the steam vents stopped.
They went on, and the slopes on either side got less. Finally they were able to scamper out of the cleft. A valley opened out before them—and it was green with trees. They were through the mountains!
They made their way down the slope, and found a rich berry patch. They fairly gobbled the berries, which tasted wonderful. Their juice helped quench Hu’s growing thirst, too.
But now the day was getting late. Shadow crossed the valley and reached up the mountain slope. It was weird, because it was coming from the wrong direction. This was morning shadow, coming at night.
Be began to whimper, picking up the subtle wrongness of this region. She wanted to go home. So did Hu. So they put down their knuckles and ran back to the narrow cleft.
But the shadow got there before them. The cleft was dark. How could they go there?
As Hu stared, he saw that the darkness was not complete. He could still see the bottom of the cleft. Soon it would be all the way dark, but there was time to get into it before that happened. So he bounded on down into it, with Be fearfully close.
Once at the base path, they ran without pausing into its narrowness, though the steam, along its close curve, through the next steam, and finally through the last one. There was the rock pile, and Bb was gone. They could get the rest of the way through!
It seemed only a moment before they were back where the band had been—but the band was gone. No problem; they sniffed out the trail and soon found it a short distance back, huddling under a rocky overhang. There was no cave, but this seemed good enough. Hu and Be had not even been missed.
* * *
In the morning the indecision remained. No one knew where to go or what to do. Most of the band were hungry, for the berries nearby had all been eaten, including unripe ones, and bugs and grubs were hard to find. A foolish rabbit was spied, and was immediately circled and pounced on; soon the redly dripping fragments of it were being avidly eaten by the dominant males. But that merely made the rest of them hungrier.
Yet Hu knew where there was food. He tried to tell his mother, but she was distracted and did not understand. So he told his half-brother Ra. “Food!” He touched his mouth, then his belly.
Ra understood immediately. He and Fa came with Hu, following him down to the crevice. There they hesitated, but Hu plunged on in, and they followed. He ran over the pile of stones and plunged through the first steam cloud. Again they hesitated, but they were hungry, so they came on through. Both were frightened, but Hu’s confidence encouraged them. They knew he would not lead them into mischief.
In a surprisingly short time they were through the narrow way and approaching the berry patch on the other side. There were other patches close below it with plenty of ripe berries. Ra and Fa pounced on the patches and gorged themselves. Hu found a separate patch, and ate too.
Then it was time to go back. They had to let the others know. Fa, with an intuitive insight, plucked a berry branch and clamped it between her teeth. Then they returned, no longer afraid of the steam path.
This time Bb was there at the rock pile. He bared his teeth as he spied Hu, thinking to attack him. Then Ra came up beside Hu and bared his teeth. Bb, alone, changed his mind and loped away.
Hu and Ra did not let it go at that. They bounded after him, screeching threateningly, forcing Bb to flee without dignity. It was fun. Fa followed close behind, enjoying the scene.
The three approached Hu’s mother. “Food!” they cried. Fa showed off her berry branch. There were several ripening berries on it. That got the attention of the others. Where had she found that, when all the plants nearby had been stripped of all their berries, both ripe and green, as well as their leaves?
Hu’s mother followed Hu, and Ra’s mother followed Ra. Several other children came too. But the dominant males did not deign to pay attention. What could children have that could interest them?
The trip was not easy, for the women were far more wary of the steam vents than the children were. But when little Be jumped blithely through, evincing no fear, Hu’s mother followed. She almost turned back when she saw the second vent, but again they managed to persuade her to jump through. Finally they brought her and the other female out to the berry patches. Then all was clear, and they all feasted.
Later that day they brought through more children and females. The word spread quickly: food! Soon all the young ones were running through the steam as if it had never been fearsome. Even the steady hissing seemed friendly.
It took time to convince the dominant males, but hunger finally compelled them. They navigated the cleft with extreme reluctance. Hu saw that their larger bulk made, the passage difficult. In the narrowest section they had to stand and sidle along. It would have been impossible for one of the brutes who had displaced their band to squeeze through.
In due course the band moved down the new slope to the thickly growing trees below. There were no brutes there, and food was plentiful. They had found their new home.
* * *
In this manner the range of the chimpanzees extended beyond that of the gorillas. The graciles were not able to oppose the robusts, but the robusts could not go as far from their home forests. It was not just that the chimps could run better on ground or squeeze through narrower apertures, but that they could forage more efficiently in difficult terrain. Perhaps their constant displacement to the fringe of the joint range forced them to be more versatile, and that helped them survive when times changed. Thus those who were less specialized for a particular habitat became survivors in varied habitats. This pattern was to be repeated endlessly as our species evolved, and it seems to have been the graciles who usually outlasted the robusts. Thus perhaps their weakness was their strength.
Within our species, men are robust, women gracile. That may be significant.
* * *
Copyright © 1994 by Piers Anthony Jacob