Humans. Homo sapiens sapiens. 7 billion strong. We of the opposable thumbs and upright gait. Builders of skyscrapers, followers of faiths, consumers of fossil fuels, and purveyors of chocolate.
There is an ethical philosophy called anthropocentrism that considers humans as the central, most significant life form on the planet and therefore hold a higher moral standard than any other species. Other life forms are valued in terms of their worth to humans. If there is any truth to this school of thought, what is it about us that makes us more important than any other species?
We aren’t the largest creature on earth, that honour goes to the blue whale which is larger than any creature known to exist on earth, including dinosaurs. The largest terrible lizard was estimated to weigh approximately 100 tonnes, which is roughly half the weight of a blue whale. The blue whale also wins the title as strongest animal based on their ability to move it’s 200 tonnes through water. But pound for pound the strongest animal is the 3cm long dung beetle, which can pull 1,141 times it’s own body weight. Without equipment, world class weight lifters typically lift between 4 to 5 times their body weight.
We aren’t the oldest living things, either. Plenty of other life forms outlive our 82 year life expectancy. Bowhead whales, Galapagos giant tortoises and a type of mollusc called an ocean quahog all live at least twice as long as humans. But in the life expectancy department it’s the flora that typically outlive the fauna. A single tree can live to be over a thousand years old – the oldest on record is a bristlecone pine in California thought to be approximately 5,000 young. In Utah, a grove of 47,000 aspen trees are all genetically the same and share a common root system. Therefore, they are considered a living entity, and while no single tree in the colony is likely more than a few hundred years old, the stand itself is estimated to be 80,000 years old.
While we can certainly make a case for being the most intelligent life form, even scientists agree that we have competition in that regard. Great apes, with whom we share some 97% of our dna with, can use tools, and have complex social structures and have been observed making human-like gestures. Leading biologist Frans de Waal documented apes shaking their head to indicate “no”, holding out an outstretched palm to ask for something and a pouty face to express displeasure.1
But if we are going to compare brain power, it’s really the dolphin that should be front and center. The cerebral cortex is the part of the brain that is associated with higher functions such as communication, organization, motor function and processing emotions. When you picture what a brain looks like you are probably picturing the cerebral cortex – it’s the great big folded part of our brain that looks like a squished up intestine. Kind of. Anyway, the folds in the cerebral cortex are thought to be an indication of intelligence. The more folds, the more intelligent the being. Dolphins are the only creature known to have more folds in their cerebral cortex than humans. The area of the cerebral cortex that governs emotions in dolphins is also more complex than the human brain. Dolphin’s emotional center is integrated with the parts of the brain that govern reasoning and motor function. Most people are under the impression that humans have the greatest capacity for feeling and empathy, but science suggests otherwise.
Even octopus with their incredible problem solving abilities give us a run for our money in the intelligence department. They can navigate complicated mazes, unscrew childproof lids, and have the foresight to carry coconut shells around with them for protection. Many researches who have tried studying these fascinating creatures report having been outsmarted by them in some way – they’ll pull plugs, escape through drains, refuse to eat sub-par food, steal tools, stare you down. They may not have backbone, but with one third of their nervous system existing in their arms, they do have something called “embodied intelligence”. This is simply a way of describing how all 8 tentacles effectively “think” for themselves. I only have two arms and if I want one of them to move, my one central brain needs to send a signal for it to do so. But the arm of the octopus has the ability to decide if it wants to reach out of it’s tank and steal an instrument off the table and the ability to carry out the task.
But we can build things, right? The tallest man made building is 2,722 feet tall. Assuming that the average human is 5ft 6inches tall, that’s almost 500 times our own size. Impressive, right? Not to a cathedral termite. These creatures are typically less than 1cm long and often build structures from grass, mud, and their own waste that are well over 6m in height – much more than 600 times as big as they are. It gets even more amazing. Not only are these structures strong enough to withstand the elements, and the weight of other animals sitting on it, but they house a complex system of hollow columns that serve to ventilate and insulate so that the temperature within the structure stays relatively constant. And that’s just what’s above ground, don’t even get me started on what lies below. Not bad for an insect.
One title that even the most cynical anthropocentric will say we’re best at is cruelty. We kill each other at alarming rates for any number of reasons. Sadly, even the notion that nature is inherently “good” is far from the truth. We are the not the only animal that will kill one of our own or wage war amongst ourselves. Many animals will fight to the death over territory, food sources, even social status. Wolf packs fight other wolf packs, raptors battle it out in the skies, even grizzly bears have a pecking order when it comes to fishing spots. Animals will also fight to the death for the right to mate with other animals. Sometimes entire colonies of insects will attack and kill every single member of another colony.
But surely we are the most dominant species on the planet, right? It’s obvious that we have the most influence over other life forms… we fragment and destroy habitat, pollute the environment, capture and even reproduce animals and plants for our enjoyment, run tests on them and manipulate their genetic make up. If we weren’t here the earth would be drastically different. What other living creature has this much impact on other life on a global scale?
As a matter of fact, bacteria. Bacteria are microscopic, single-celled organisms. They can live in almost any environment from sea ice to desert sand and on things living and non-living. Bacteria can be found on a tiny grain of sand on a beach, on your cell phone and even in your mouth. Under the right conditions, one bacteria cell can reproduce fast enough to create a colony of well over 16.5 million other bacteria cells in just 8 hours. When conditions are not favorable, bacteria have found a way to become dormant until conditions change. They can be dormant for centuries at a time and are able to survive the most hostile environments including, temperature extremes, radiation, and desiccation. The first living organism on earth was likely bacteria. In fact, scientist believe that bacteria played a part in making the world hospitable for other life forms to evolve.
And bacteria can kill us. Black death, which ravaged Europe in the 14th century, and killed approximately half the population, is believed to be caused by a bacterial infection that spreads through flea or other small animal bites. E. Coli, Cholera, salmonella and tuberculosis are all types of bacterial infections that can kill humans. According to the world health organization, in 2014, 9.6 million people contracted tuberculosis and 1.5 million of those eventually died from the infection.
Bacteria in the environment help break down material and cycle elements like nitrogen and carbon through the atmosphere. In our own bodies, bacteria help with the digestion of food and in regulating our immune system. We probably have ten times more bacteria on us than we do human cells containing our own dna. If bacteria were to disappear from the earth entirely, it is unlikely that other life forms would be able to survive. We certainly wouldn’t.
Does that make them the most important life form on the planet?
Ecocentrism is the ethical philosophy that nature is its own entity and all life forms have their own intrinsic value or worth that is unrelated to any quantifiable benefit to humans. A blue whale is important because it is a blue whale. It is valued not only for it’s size and strength but because it rears young, consumes krill, and migrates thousands of miles every year. It’s important because it exists.
What do you think – are some species more important than others or is our worth the same?
1 Pollick, Amy S., and Frans BM De Waal. “Ape gestures and language evolution.” Proceedings of the National Academy of Sciences 104.19 (2007): 8184-8189.