The Apes' Survey (5): Footprints on Rock

"My name is turmoil, and is written
In stone"
(Carlos Drummond de Andrade)

The joints of the Apes snapped because of the cold, when they said goodbye to the host who had provided the most pleasant hours of the expedition up to that point and, in the dead of night, resumed the descent of the mountain’s face that lay opposite to the one they had climbed.
Within hours, the four reached a gorge, which they crossed carefully not to climb inadvertently the multiple slopes of the impressive formation. At the end, they found a barren and wavy land that looked like a desert. And thought they were on the right track.
The landscape had been greatly transfigured. Instead of the ice and the mountain’s typical trees, a sandy soil stretched so vastly that it seemed to jam up on the horizon. And instead of the bitter cold and the wild aroma that moisture drew from the soil in the highlands, a warm wind blasted the faces of the travellers. However, so different scenarios had something in common: both concealed mysteries.
In the highland’s desert, those mysteries were concentrated in sharp cliffs at intervals of a few miles from each other, that offered refuge to all sorts of bizarre creatures from Arthropods to Mammals and gangs of Men. The ground burned during the mornings and afternoons, but cooled as the air temperature declined to the level of temperate regions. These features, which are covered in the word rustic, somehow imparted the place its own charm. They also taught that space, more than an abstract data, is existence's greatest condition of possibility and usually shelters only the strong or very cooperative. Especially the very cooperative.
After walking two hours under a scorching sun, the Monkeys saw a small oasis, where they stopped. First, they quenched the thirst in the fountain that sprang like a miracle from the sandy floor. When satisfied, they admired the magnificent trees of the place and ate their pendant fruits. Finally, as the heat increased, they took refuge in a cliff that rose behind the source as a finger pointing to the sky.
Inside the rock, there were no living beings, no single plant, except for mosses that insisted on covering some stones. Rocks, however, were everywhere: on the walls, the ceiling, and especially on the ground. So numerous were they that covered the floor as a treasure of shells that hide pearls. The reader will understand why.
Not resisting the unusual supply of pebbles, Monkey Tile began to play with them. Grabbed a few, threw others, and rubbed still others. He soon realized that a part of the pebble could be sharpened and wielded as a weapon. And did not hesitate to lend the stones formats of guns, in which he was imitated by his companions. And they started to play and to run and to join battle with the inert forms inside the cave. And as they exercised, their shadows projected on the wall of the cave entrance, making them fight with spectra and almost believe they were real. In the end, it might be concluded that Chance had made them enact the Platonic myth in a way more appropriate to science, which examines projected images as well as facts.

And as if he answered Chance, Tile struck a stone with the tip of a sharp pebble, and with such power that it opened up like a book, in equal parts. For general uproar and confusion, two crisp brands emerged from the faces that had lain at the heart of the mineral for ages. Both were shaped like feet. At the bottom of one, something was embedded, and in the corresponding position of the other, a small pit denounced the location where the object had rested before Tile’s stroke unraveled it.

Tile took the half stone with the object jammed. He looked at it in multiple angles. As the gloom did not help him see, he took the stone out, so that under sunlight he might submit it to the desired scrutiny. And astonishment fell over all, when seeing consecutively the distinct shape of a small animal in it!
- It's a Trilobite! Glass screamed in ecstasy.
- Yes, a Trilobite! nodded the one who had cracked the rock. And the brand in which it rests is a human footprint! (*)
- Humm, the cave must contain other stones with such animals... Potsherd completed. We have discovered a fossil deposit!
The conclusion seemed sensible. However, still skeptical, the four continued to look at the footprint with the animal for some time. Looked over and over, as if struck by a crisis of laziness. They also groped and discussed it, before deciding to pursue other fossils. But after taking this decision, they spent the rest of the afternoon in striking and opening stones with other stones, with clumsy tools, even with hands. Though playing, for playing was their role in the world, they already did so in a serious way.
With joy similar to that which had seized them moments before, the friends dicovered other Trilobites and other human footsteps in some of the rocks they opened. However, a stone like the first one, with a Trilobite on a footprint they did not find. Yet gave over quite satisfied.
By the end of the day, they harvested coconuts, bananas, cherries, chinaberries, and other fruits, that carried to the cave entrance. Byproduct of this operation was a trail of fruits throughout the way to the cave. If meant no advantage to the Apes themselves, the trail certainly served the Birds. Anyway, when the job was over, the friends sat down to eat. Did it quite fast, as hunger assailed them, but not fast enough to prevent conversation.
- The fossils we found are of Men and Trilobites, recalled Glass while they ate. The rocks being scattered and not arranged in strata means that Men and Trilobites lived at the same time in the same site.
Potsherd had long waited the obvious though unusual conclusion. When it was uttered, he confidently exclaimed:
- But the Trilobites became extinct 250 million years ago! How could they have lived with Men, who have been on Earth for only two million?
And without waiting for an answer, he brought to the center of their conversation some data that had not gone unnoticed, but lacked being discussed:
- Just note the rectilinear shape of the edges of the footprint. It could only be produced by a shoe, never by a bare foot. The walker smashed the little animal with a sandal.
- Which brings us to an even more recent period, in which Men already wore shoes and clothes, intervened Ware.
- But the extinction of Trilobites, Glass remembered, is well documented in Paleontology. They abound in fossils up to 250 million years ago and suddenly disappear. The fossil testimony is corroborated by the total absence of Trilobites today. None of these creatures, once abundant, has been found alive or recently dead.
- You are right, said Ware. The coexistence of Men and Trilobites can be explained in several ways. We can retreat Men to the time of these animals or bring them into the human era. What can’t be denied is the coexistence attested by so many stones.
- Nor should we lose sight, interrupted Glass, that Trilobites may have been extinct between the time in which they prospered and the appearance of humans on Earth. As much as the science of origins reflects the image of a tree, with many categories emerging from fewer, and these from only three or four, nothing must have prevented the groups from emerging one or more times in different places and ages. Trilobites as the ones we found may have emerged, been extinguished and reappeared. At least this hypothesis can explain their coexistence with Men, which the stones show.
- Days ago, recalled Ware, the forest stones shouted to us. These are not less about to cry...
The Monkeys spoke while thinking, and thought while speaking. Their discussion reflected the always distressing circumstances of the investigation. The turmoil of the adventure induced turbulent moods, that led to messy and passionate discussions. But neither the difficulty of the adventure, nor the heated discussions sufficed to stop their undertaking.
Glass pointed out the relationship of their fossil finds with the modern theory of kinship of living beings:
- A population having almost the same genetic heritage as the first being of its kind does not mean it descends from him. The Trilobites we found today share some genes with their elder peers, but do not descend from them, since the first Trilobites were extinct. The dogma of the single origin of each group falters. And if it does, we are not obliged to conceive offspring as a synonym for origin from one and the same ancestor trunk.
After considering for a while, Glass also formulated two questions as one who fires well-aimed arrows:
– Shouldn't we extend our reflections on the Trilobites to other groups? If a being on Earth may descend not from the first specimen of its kind, but from a later one, isn’t it legitimate to think that a group may have originated several times and not only one? A scientific law, a natural regularity like the common heritage of all beings of a kind shall mark out, but not hamper thought. It cannot enforce intelligence to disregard any possible explanation of phenomena. Especially explanations that rest on evidence so clear that seems to claim like the forest stones.
And added:
- Darwin created a clear-cut idea of descent with modification. He even carved it as an artist. However, as ancient happenings changed the existing species, recent findings demand changes in the concept of descent. Change over generations does not necessarily imply a single ancestor. And if it does not, the offspring of beings of all ages may look even more like a web, with interwoven yarns, than a tree.
It can’t be denied that so many conjectures, questions, doubts and contradictory evidences mirrored minds in atrocious conflict. But the greater tumult that assailed the friends and made them quiver was laid on the facts. From these it was loose and imprinted on the soul of the four, as a stamp of many truths or a light beam passing through a prism.

(*) A fossil trilobite within the footprint of a man wearing sandals was discovered in 1968, 45 miles away from the city of Delta, in the United States, by William J. Meister. The text is based on this real finding.