[Note: This is the second sample from my rough draft of a far from finished new book, Wild Free & Happy. I don’t plan on reviewing more books for a while. My blog is home to reviews of 196 books, and you are very welcome to explore them. The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.]
Our Tree Critter Ancestors
The dawn of life on Earth began maybe four billion years ago, with the emergence of single-celled beings, the common ancestors of all forms of life, including us. Let’s fast forward to around 65 million years ago, when our first primate ancestors came into existence, not long after dinosaurs moved off the stage. These critters were squirrel-sized, and lived high above the ground in the humid tropical rainforests of Mother Africa. They were probably insectivores, furry little hunters that dined on the delicious flesh of bugs and grubs.
Arboreal (tree-dwelling) primates had little need for a powerful sense of smell like most terrestrial (ground-dwelling) animals have. What they needed was excellent stereoscopic vision, via forward oriented eyes that provided accurate depth perception, so they could scamper and leap through the branches without mishap. Being able to perceive colors made it easier to find ripe fruit, which was a primary food source. Even today, bright red objects attract our attention.
Their hands and feet evolved into forms fine-tuned for grasping bark, vines, and branches, with toes and fingers tipped with nails, not claws. Fingers were long and curved, wrists freely rotated, and shoulder joints were flexible. An acute sense of touch and a sharp mind helped them excel at airborne acrobatics. Humans retain a number of these arboreal traits.
Our ancestors were tree-dwellers for most of the 65 million year saga of primates. A look in the mirror shows clear evidence of this heritage. Most primate species today remain partly arboreal. Humans are the only living primates that are fully terrestrial. Large male gorillas do not sleep in the trees, but the other gorillas do.
In the rainforest, food was available year round, so our ancestors enjoyed an easy life. Living amidst a cornucopia of organic fruit, nuts, insects, and assorted tree critters, they could live happily without tools, fire, cooking, cell phones, or psych meds. The climate was comfortable, so there was no need for clothing. A simple tree nest was all they needed. It was a wonderful way of life, while it lasted. They only used renewable resources, and they left no permanent scars on the forest. Like all other animals at the time, they had a way of life that was genuinely sustainable.
Shift to the Savannah
Climate change is a trickster that takes great delight in periodically pulling the rug out from under stable ecosystems, and watching them scramble to survive. It’s an exciting roller coaster of hot and cold, wet and dry, calm and stormy. Species that can’t adapt to changing conditions go extinct, creating opportunities for other species to fill their ecological niche. The show of life must go on.
Long, long ago, in Mother Africa, the climate was warm and moist, home to the magnificent rainforests in which primates evolved. Later, around five million years ago, as glaciers grew in the Northern Hemisphere, the climate in African rainforests began to shift to cooler and dryer. By two million years ago, lush rainforests were far smaller, largely replaced by expanding savannahs (grasslands with scattered trees). If it wasn’t for climate change, you might be sitting naked on a branch today, wild, free, and happy in a lush rainforest paradise, nibbling on fruit with your friends and family, in a clean, healthy, sustainable world.
As the rainforests shrank, our tree-dwelling ancestors were something like tadpoles in a puddle that was drying up. Many species of arboreal critters went extinct, but not all of them. The ancestors of chimps, bonobos, gibbons, and orangutans were able to remain in the forest and avoid extinction, while baboons, gorillas, and our ancestors took a deep breath, moved to the ground, and tried to adapt to a new way of life.
On the savannah, our early ancestors were weird looking, funny smelling undocumented immigrants, attempting to survive in a habitat for which evolution had done little to assist them. Their limited speed, size, and strength were serious drawbacks. They were newcomers in a grassland neighborhood where most of the long-term residents had been coevolving for millions of years. The new neighborhood included numerous large carnivores that were strong, fast, and equipped with sharp claws and fangs. They specialized in weeding out the injured, sick, elderly, immature, and inattentive. Many of our ancestors became organic cat food.
To survive, our ancestors used several defensive strategies. They lived in groups, where many eyes were constantly paying attention to the surroundings. When someone noticed a threat, loud calls were made to alert the gang, and the predator lost the advantage of surprise. Sometimes they mobbed hungry predators, aggressively assaulting them. Other times they quickly scattered in every direction. The ancestors were careful to be as invisible as possible. They chose sleeping places that offered the most security. As a result of their cleverness, luck, and risky choices, an enormous number of ground-dwelling primates survive today.
Rainforests have high biodiversity, they provide a pleasant home for huge numbers of species. Savannahs support far less biodiversity but, unlike dense forests, they provide excellent habitat for many large animal species. A square mile of rainforest contains tons of biomass in its trees, far more than a square mile of grassland, but grassland can produce more new biomass every year, primarily during the wet season. This nutritious vegetation, which includes high-energy seeds, grows close to the ground, a convenient location for grazing animals.
The biological productivity of grasslands (savannahs, prairies, and steppes) encouraged the emergence of large herds of herbivores and their predators. When our ancestors moved to the ground, evolution had not equipped them for hunting large game, or escaping from speedy carnivores. They had two options, adapt or go extinct.