The phrase “survival of the fittest” is often used to describe the way species evolve over
time. It highlights that only the most successful have offspring, passing on their genes to the next generation. However, by using language like this, it’s easy assumed that all species in an ecosystem are constantly working against each other, and that only the most aggressive or strongest species can survive. While it is true that predators must catch and kill their prey and parasites must take resources away from their hosts, these are only examples of a wide diversity of relationships involving multiple species collectively known as symbiosis.
Humans often separate themselves from discussions of the ‘natural world’, but it shapes us
as much as we shape it (if not more)! Inspired by ZooLab’s own ‘Symbiosis’ workshop, let’s take a look at some of the ways humans have formed relationships with the various species in our environments throughout history!
‘Symbiosis’ is a term used to describe any type of long-term, repeated interaction between
two different species. Mutualisms are special kinds of evolved relationships in which both
partners benefit from the interaction, evolving specially to provide for their partner. Great
examples are everywhere; think about how bees pollinate flowers in return for sugary nectar,
or how clownfish eats an anemone’s parasites in return for a safe place to live. Often, these
cooperative relationships shape ecosystems just as much as negative relationships like
parasitism and predation. Let’s explore some of the most dazzling examples for human/ nature relationships below.
No discussion of human-animal relationships would be complete without first talking about
our furry, feathery and scaly friends. Are our relationships with our pets mutualisms? It’s
difficult to say for sure.
Historically, dogs and cats could absolutely be described as mutualists. By encouraging ancestral dogs around our campfires, we gained both protection and a hunting companion, and the dogs gained reliable campfire scraps and warmth. The same can be said of mice-catching ancestral wildcats. In modern times, whilst we still love spoiling cats and dogs with food and warmth, the benefits we gain are less clear. Outside of specialist cases like guide and livestock-herding dogs, it seems that much of our benefit from modern relationships with pets can be chalked up to the fact that we simply enjoy their friendship, companionship, and cuteness!
The honeyguides are a family of starling-sized birds from Africa and Asia. They are notable
for their rather precarious fondness for beeswax and bee grubs, a taste that has led to their
unique relationship with the native peoples in their range, such as the Yao, Hadza and Boran. Using a special call, some honeyguides will guide human trackers directly to honeybee nest. The humans use smoke to subdue and excavate the colony to collect its honey, leaving the wax and grubs for the birds. Studies have found that the birds reduce the hunting time of the Boran people by over 60%, and that up to 10% of the Hadza diet can be attributed to honeyguide collaboration. The relationship is thought to date back thousands if not millions of years. As both species benefit, it is a classic example of a mutualism.
Almost every animal that has a gut has it's own gut microbiota, the scientific name for the
population of bacteria, archaea and fungus that live inside our digestive system! In most
cases, they actively help us by breaking down our food, producing essential vitamins and
preventing harmful bacteria from growing by secreting chemicals and competing for space.
There is even a rising body of evidence suggesting that a diverse and healthy gut community