(May 19, 2016) More benign than nature, and more sentimental about protecting species, humanity deserves more recognition.
On Monday, the anniversary of the birth of Carolus Linnaeus, the International Institute for Species Exploration will announce which of the 18,000 new species discovered in the last year will be honoured as the Top 10 New Species.The Top 10 — last year they included a cartwheeling spider and a frog that gives birth to tadpoles — are chosen to highlight the planet’s boundless biodiversity. Only two million of the countless numbers of species that have inhabited Earth have been named to date, a never-ending process started in the mid-18th century by Linnaeus, the “father of modern taxonomy.” The process is never-ending partly because nature continually creates new species. And partly because humans, too, continually contribute to the planet’s biodiversity through new species borne of our commercial and industrial activities.
The history of the London Underground, excavated at the same time that Charles Darwin published the Origin of the Species, illustrates man’s role in originating species. During World War II, when the tube’s tunnels doubled as overnight bomb shelters, Londoners sheltering below ground found themselves bitten by especially aggressive mosquitoes. Half a century later, a curious London doctoral student determined that the underground mosquitoes differed fundamentally from their aboveground ancestors, which fed off birds. The undergrounders, thought to have been stranded when the tunnels were largely sealed-off from the surface, needed to adapt in order to survive, and adapt they did. In their birdless subterranean habitat, they became mammal biters, feeding on rats, other animals and the maintenance men working underground. Unlike the surface mosquitoes, which need a lot of space in which to mate, the underground mosquitoes adapted to subterranean life by mating in closed areas. The underground mosquitoes soon evolved to be too distinct to interbreed with other mosquitoes — a process called speciation, or the creation of new species.
New species often result when a population becomes geographically stranded and must either adapt or die out. This happens through all manner of natural phenomena, such as when plants and animals find themselves on the isolated habitats created by volcanic eruptions, as after the formation of the Hawaiian archipelago several million years ago. Its 132 islands, atolls, reefs, shallow banks, shoals, and seamounts extend over an expanse of 1,500 miles, creating one of the world’s most bio-diverse areas. Earthquakes, even severe storms, can create islands, as can humans — Hong Kong’s main airport, the world’s busiest cargo airport, was built on an artificial island. Other manmade islands are created for recreational or residential purposes; all have ecological niches with the potential to originate new species over time.
More routine human activities also create breeding grounds for new species. As explained by Michael Schwarz, an associate professor at Australia’s Flinders University and an expert in evolutionary ecology, “in Australia, clearing forests for agricultural land has split up populations of gliders, possums and ground-dwelling marsupials. These separate populations will go on evolving until they are too genetically different to interbreed.”
Our contribution to species destruction pales in comparison to nature’s
The shipping industry, explorers and colonists are also credited with spurring new species. The Portuguese who came to the volcanic island of Madeira in the 15th century, dotting its perimeter with settlements isolated from one another on land by steep cliffs, introduced mice to each settlement. Because the mice couldn’t roam to interbreed with their country cousins in other parts of the island, the mice in the various settlements evolved separately, ending up with between 22 and 30 chromosomes compared to the 40 in the European mice that originally came to Madeira’s shores.
In the crucible that is Planet Earth, species are created and destroyed in great numbers. Scientists estimate that the planet has lost 99 per cent of all species that ever existed, thanks to events such as the Great Dying of 250 million years ago that wiped out 97 per cent of all species, and the mass extinction that did in the dinosaurs 66 million years ago. Man’s contribution to the destruction pales in comparison — a paper published in Science two years ago identified but 322 lost species over the past 500 years, or less than one per year on average, although many other, unidentified species were doubtless lost due to manmade activities.
Man is more benign than nature, and more sentimental about protecting species — we deplore their loss, spend huge sums in their defence, pass legislation to protect the likes of snail darters. We take a lot of blame when species are lost or even threatened. We should also take some credit when species are gained.