Why in news?
- Many scientists now believe humans are living through a “mass extinction,” or an epoch during which at least 75 percent of all species vanish from the planet.
- Humans have driven thousands of species to the edge of extinction through habitat loss, overhunting and overfishing, the introduction of invasive species into new ecosystems, toxic pollution, and climate change.
- The World Wildlife Fund (WWF) estimates that populations of vertebrates have fallen by an average of 60 percent since 1970.
- Recent vertebrate extinctions in the wild include the northern white rhino, which lost its
- last male member in 2018, and Spix’s macaw, a blue parrot native to Brazil.
- But 99 percent of Earth’s species are invertebrates, and 40 percent of the species known to have died off since 1500 were land snails and slugs.
- There are 26,500 species threatened with extinction, according to IUCN which includes 40 percent of amphibian species, 33 percent of reef-building corals, 25 percent of mammals and 14 percent of birds.
- A third of insect species are endangered, and the total number of bugs on Earth is dropping by 2.5 percent every year.
- Hence many scientists believe humans are living through a “mass extinction”.
- The previous five mass extinctions occurred over the past 450 million years; the last one occurred about 66 million years ago, when the aftermath of a massive asteroid strike wiped out the dinosaurs.
- These prior events differed from the current one, as this time it’s humans who are driving the mass die-off.
- The loss of species can have catastrophic effects on the food chain on which humanity depends.