HONOLULU Unlike previous mass extinctions, species are now rapidly disappearing due to human causes. Researchers examined the loss of mollusks and found that Earth’s extinction rates are higher than if humans weren’t there.
What You Need to Know
- The sixth mass extinction is unique because it was the first to be caused by humans.
- Although the sixth mass extermination has been discussed for more than thirty years, some people still remain skeptical or deny its existence.
- To determine the loss of species, researchers looked back at 1500 AD and examined mollusks.
- According to the researchers, 7.513% of 2 million species that are known to have disappeared since 1500 AD according to their data.
Most scientists agree that Earth has experienced five previous mass extinctions, each with losses of more than 75%.
According to a paper published in recent times, the sixth mass extinction is unique because it was the first directly caused by humans. Biological ReviewsBiologists from the University of Hawaii at Manoa, and the Museum National dHistoire Naturelle, Paris, France.
The paper says that although discussions about the sixth mass extinction have been ongoing for more than 30 year, some people still remain skeptical or deny that it is occurring. Some people believe that the extinction rate estimates are exaggerated. Others claim that there are new species to offset the losses. Others argue that it doesn’t really matter since it is already too late and we are in the midst a mass extinction. Deniers also believe that humans are part the natural world and therefore, extinctions due to humans are part evolution.
Robert Cowie, the lead author of the study, stated that while there is ample evidence of an increase in the rate of species extinctions and declining numbers of many animal and plant species, some people deny that these phenomena amount of mass extinction. Press release. This denial is based in a biased assessment that focuses on birds and mammals, but ignores invertebrates. Invertebrates are the majority of biodiversity.
To determine the extent of species loss, researchers looked back to 1500 AD. They studied mollusks. Extinct species studies often focus on mammals, especially those by The International Union for Conservation of Natures Red List. However invertebrates which include mollusks arthropods annelid and Cnidarians make up roughly 95% of all known animal species.
Cowie stated that including invertebrates was crucial to confirm that we are witnessing the Sixth Mass Intinction in Earth’s history.
Because mollusks are a well-known group invertebrates, the researchers concentrated on them. Because many extinct species of mollusks are land snails that have left behind shells and not many other invertebrates, there is more information about them than any other invertebrates. The vast majority of extinct species, such as moths or butterflies from Hawaii, were not discovered until they were collected and documented.
The researchers first looked at the extinctions of land snails and slugs. They then extrapolated the data to conclude that between 150,000 and 260,000 species of the 2-million species, approximately 7.513% have disappeared since 1500 AD.
Although the sixth mass extermination is imminent, the researchers pointed out that it has yet to occur. Researchers write that it could happen in just one or two centuries if there is nothing done to slow down or stop the current rate at which biodiversity loss is occurring.
The paper suggests conservation efforts are important even though they tend to focus on mammals or birds. It might be more effective to focus on specific threats. Hunting bans have been beneficial for marine mammals, while eradicating invasive species has been beneficial for native faunas and invertebrates living on islands. DDT bans have also helped to bring back the peregrine Falcon in North America. The paper states that these acts will slow down the process, but they are not sufficient.
According to the paper, dedicated conservation biologists as well as conservation agencies are doing their best, focusing mainly on endangered birds and mammals. Some species may be saved from extinction. We are not optimistic about the fate for most of Earth’s biodiversity. Many of it will disappear without our ever knowing.
The paper called for spreading the message about biodiversity and the fact that humans are causing extinction at an increasing rate. Taxonomists were urged to catalog all species before it is too late, even the less obvious and often icky invertebrate ones. At least 6,000,000 species are still undocumented.
The researchers state that it is essential to fight the crisis. Manipulating it is a violation of moral responsibility.