“Fantastic Beasts and Where to Find Them.”
That would be a good title for the biodiversity conference, COP15, in Montreal. The latest estimates put the number of species on Earth at around 8.7 million plus or minus 1.3 million. In other words, scientists estimate there is somewhere between 7.7 and 10 million unique species on this planet.
And many of them are truly fantastic with a wide variety of body plans, pigmentation, organs, and senses. It doesn’t take much to find accounts of uniquely bedazzled spiders or pictures of a carnivorous plant or a rare sighting of a Kermode bear. Life is amazingly diverse.
Estimates of the number of species catalogued range from 1.2 to 2 million but we recognize there are more unknown than known.
The planet is dominated by plants and specifically trees. Plants make up 82 per cent of the biomass with teeny tiny bacteria occupying second place at 13 per cent. But because bacteria are so much smaller, bacterial species outnumber all other species combined by a wide margin.
Animals account for only 0.4 per cent of Earth’s biomass and humans account for only 0.01 per cent. In the grand scheme of things, we are a rounding error. The tragedy is that wild mammals and birds only account for 0.0016 per cent. Livestock, on the other hand, out masses even humans accounting for 0.018 per cent. The vast majority of animal biomass is composed of arthropods, fish, annelids, molluscs, cnidarians, and nematodes.
But even with all of this diversity, life on this planet is in danger.
COP15 on Biodiversity is just the latest conference trying to understand and come to terms with the complexity of the entire ecosystem of the planet. And perhaps more importantly, what are the tipping points?
Life is built on complex mutual dependencies. As an example, when wolves were eliminated from Yellowstone Park, their prey underwent a population explosion. This led to the destruction of forest landscape as these animals over-grazed. And that led to the loss of bird and fish habitat which affected other species. And so on.
This is an easy example to see because the species involved are large mammals. But the interdependence of life extends throughout the entire web. Who knows what will result from the extinction of one species? Biodiversity is complex and important.
Todd Whitcombe is a chemistry professor at UNBC.
