Buzz
Humans are a fascinating contradiction. Our past is filled with groundbreaking scientific achievements that have improved our lives. Yet, at the same time, we often use these very advancements to cause unnecessary suffering. This paradox is what we call 'human nature.' Amid all the negative attention we tend to get, we frequently forget the positive potential we possess. With the rise of environmental awareness, more and more attention has been drawn to the countless species we've driven to extinction. To offer some perspective, here are ten animals and plants whose survival is entirely thanks to human intervention.
10. Head Lice
The common head louse can only live on humans. Many parasites are species-specific, and it’s easy to overlook that when one species goes extinct, many parasites linked to it disappear as well. However, among the various parasites that rely exclusively on humans, head lice stand out because they offer an unexpected benefit. A childhood bout with head lice, though irritating, is usually harmless. In areas with poor sanitation, head lice help bolster the immune system against the more dangerous body louse, which spreads a number of harmful and potentially deadly diseases. Although modern society has lessened the need for this immunity, those living in poverty still receive protection from head lice. In this sense, head lice continue to help humans, and they can’t survive without us. While we may not have intended it, simply by existing, we have allowed this species to endure, and even today, people continue to benefit from them.
9. Avocados
Many plants depend on animals to disperse their seeds. These plants coat their seeds with a delicious layer to entice animals to consume them and later excrete the seeds, often with a natural dose of fertilizer. This not only guarantees that the seeds have proper nutrition, but also aids in spreading the plant to a wider area. The avocado evolved in this way. However, given that an avocado seed is about the size of a chicken’s egg, one might wonder: what type of animal could have possibly passed an avocado seed through its digestive system? Humans, though relatively large, have a digestive tract that’s only about 2mm wide. The animals capable of swallowing and passing an avocado seed must have been much larger. These giant creatures went extinct around 12,000 years ago, and with them, the avocado could have disappeared too. Thankfully, the resourceful people of Central America took it upon themselves to cultivate the plant by hand. Though not a natural process, this method has kept avocados alive for thousands of years. Today, they are entirely dependent on humans for propagation. Without human cultivation, avocados would quickly fade from existence.
8. Hamsters
At the start of the last century, a zoologist captured a few rare and unusual rodents in Syria. These creatures had been described a century before and were given the name Syrian hamsters, or golden hamsters. Among the captured specimens, there was only one female. After these hamsters were captured, sightings of them became increasingly rare, and it was believed that they had gone extinct in the wild. After studying and breeding them for several generations to boost their numbers, a few of the hamsters escaped, while the others became the ancestors of the pet hamsters we know today. Every golden hamster in existence can be traced back genetically to that one female caught long ago. All evidence suggests that the wild golden hamsters found in Israel today also trace their lineage to the original escapees. Without the intervention of that one biologist, neither domestic nor wild hamsters would exist today.
7. Ginkgos
Long ago, it is said in legend, a Chinese Emperor had a particular fondness for a tree and decided to plant it in the Imperial Garden. The royal gardeners tended to the tree, helping it to thrive, and it was cherished for many lifetimes, as the species of tree typically lives for over five centuries. Its seeds were carefully harvested to grow future generations. Centuries later, this tree, the ginkgo, was thought to be extinct elsewhere in the world, existing only in fossil records. However, as China began to open its doors to the West, it was revealed that the tree, once believed to be extinct and only known through ancient fossilized imprints, was still flourishing due to the affection of an ancient emperor. Today, Ginkgo biloba trees can be found worldwide, but all of them can be traced back genetically to a single tree, or perhaps a small group of trees, from nearly 3,000 years ago in China.
6. Silkworms
Bombyx mori, the silkworm, is entirely reliant on humans for its species' survival. Despite their name, silkworms are not worms, but rather larvae or caterpillars. They spin silk to form their cocoons, a material that humans have found invaluable. For over five thousand years, humans have bred silkworms specifically for their silk, while the wild varieties of silkworms have gradually faded into extinction. Those bred for silk are unable to function in the wild. Even after metamorphosis, they cannot fly or feed themselves, as their wings are rudimentary and their mouthparts too small to be used without human assistance. Domesticated silkworms lack the instinctual fear of predators and cannot survive without human intervention. Mating must be facilitated by handlers. Despite these limitations, silkworms live a relatively comfortable life, largely because healthy, well-fed silkworms produce the best quality silk.
5. Bermuda Petrels
The Bermuda petrel, a rare bird native to Bermuda, was on the brink of extinction after European settlers introduced rats, dogs, and other animals that devastated its population. For over three centuries, this bird was believed to have vanished entirely. However, in 1951, 18 individuals were unexpectedly discovered nesting along the coast, prompting immediate legal protection for the species. Even with such a small population, the future of the Bermuda petrel seemed grim. To protect the nests, walls were built to isolate them from other wildlife, and conservationists carefully created additional nest sites to help the birds thrive. In 2003, volunteers risked their safety to save the birds during a hurricane, rebuilding destroyed nests and ensuring their survival. Today, the population has grown to around 250, and with continued human effort, the Bermuda petrel may one day flourish in the thousands again.
4. Jellyfish Trees
This tree, named for the jellyfish-like appearance of its flower centers, was once presumed extinct. However, it was rediscovered toward the end of the last century, now existing only in a few vulnerable populations carefully protected in national parks on the Seychelles. This ancient plant, poorly suited to the modern climate, has seen its numbers naturally decline over thousands of years due to climatic changes. By 1970, only three trees were found struggling to survive. Now legally protected, botanists are working diligently to figure out how to ensure its survival. The tree's seeds cannot germinate in the wild, and humans have only managed to sprout them under very humid conditions. Although the population has now grown to fifty, this tree remains ill-suited to the current climate, and without constant human intervention, it cannot compete with more adaptable species.
3. Mongolian Wild Horses
Most wild horses today are feral descendants of domesticated ancestors. However, the Mongolian wild horse is the last true wild horse still in existence, never having been domesticated. Ancient cave paintings show that humans hunted these animals as far back as 20,000 years ago. Since then, the climate has gradually warmed as we enter an interglacial period, causing the horses' habitat to shrink and their population to dwindle over millennia. After World War II, all wild Mongolian horses were lost due to habitat destruction caused by the war or because they were hunted for food by desperate German soldiers. The last zoo populations also dwindled, leaving only 31 horses by 1945. Of these, 9 were able to breed, and today, their population has been carefully nurtured to 1,800. About 300 of these horses have been reintroduced into nature reserves in Mongolia and China, where they once roamed free. These wild horses are now protected with great care, and their species is expected to recover.
2. Wollemi Pines
Though not technically a true pine, the Wollemi pine was known only from fossil records until 1994, when a park ranger unexpectedly discovered one in the Wollemi National Park in Australia. It was quickly recognized as a living fossil, and while not extinct, it had nearly vanished. Fewer than one hundred trees remained, many of them sick, dying, or unable to reproduce. Mathematical models predicted that without human intervention, the species would have been truly extinct in under a millennium. A conservation program now protects the tree by law, and thousands have been successfully cultivated. These trees have even been promoted in New South Wales as a local alternative to Christmas trees; they are kept in pots during the festival season and planted after it concludes.
1. European Bison
Thylacines, also known as Tasmanian tigers, were once the largest carnivorous marsupials in the world. These creatures became extinct on mainland Australia thousands of years ago but survived on the island of Tasmania. However, their numbers dwindled due to disease and the loss of their prey species. The arrival of European settlers hastened their decline, as hunting and competition with domestic dogs intensified. The last known thylacine died in captivity in 1930. Yet, scientists are optimistic about reviving this unique species, as preserved specimens still contain enough DNA for potential resurrection. With advancements in technology, the possibility of bringing back the thylacine may one day become a reality, a testament to humanity's ability to both advance its own species and preserve others.
The thylacine, or Tasmanian tiger, was once a dominant predator in Tasmania, but human intervention led to its downfall. While these carnivorous marsupials thrived in isolation on the island, their numbers began to decline with the advent of European settlement. Overhunting, disease, and the destruction of their prey base contributed to the extinction of the species. The last known thylacine passed away in 1930 at the Hobart Zoo, but there is hope for revival. DNA from preserved specimens offers the possibility of bringing this unique animal back to life, allowing future generations to witness this species once more. The return of the thylacine would be a remarkable achievement in conservation and biotechnology.
Although many species have been artificially created by humans, few have been driven to extinction and may potentially be revived. The thylacine, or Tasmanian tiger, is one such example. Once the largest carnivorous marsupial, the thylacine went extinct in the wild in mainland Australia thousands of years ago but lingered in Tasmania until the arrival of European settlers. Overhunting and the introduction of domestic dogs led to its eventual extinction, with the last known individual dying in a zoo in 1930. Nevertheless, there is hope that this species could be resurrected, as preserved specimens still contain viable DNA. In the future, advancements in technology may allow us to bring the thylacine back, demonstrating the power of human ingenuity to restore a lost species.
