Forgotten species can go extinct twice - study

The researchers urge that more efforts be made to prevent societal extinction.

Humans have caused the extinction of many hundreds of bird species over the last 50,000 years (photo credit: TEL AVIV UNIVERSITY)
Humans have caused the extinction of many hundreds of bird species over the last 50,000 years
(photo credit: TEL AVIV UNIVERSITY)

Species can actually go extinct more than once, according to Ben-Gurion University of the Negev researchers, collaborating in a new study with European scientists. In a biological sense, species become extinct when their last member the last animal of a species stops breathing. But they can also become extinct a second time, according to the findings, published recently in the journal Trends in Ecology & Evolution

When a species disappears from our collective memory and cultural knowledge, it becomes extinct in a unique way. That second form of extinction – societal extinction – is the subject of the new study investigating how troublesome this phenomenon can be. For instance, the replacement of traditional herbal medicine by modern medicine in Europe is believed to have degraded general knowledge of many medicinal plants.

The researchers urge that more efforts be made to prevent societal extinction – because as more and more species disappear from our memories, there's evidence that it alters our perception of how important it is to protect what remains.

Ben-Gurion University of the Negev (BGU). (credit: AMERICANS FOR BEN-GURION UNIVERSITY)Ben-Gurion University of the Negev (BGU). (credit: AMERICANS FOR BEN-GURION UNIVERSITY)

Co-author of the study Dr. Uri Roll from BGU pointed to the example of communities in southwestern China and indigenous people in Bolivia who have shown loss of local knowledge and memory of extinct bird species. 

"Such loss of memory got to the point where people were unable to even name those species, and didn't remember what those species looked like, or their songs", he explained. "Similarly, the extinct Japanese wolf, okami, has only a few specimens that can be found in museums nowadays, which challenges memory of the species within Japanese society."

Ivan Jaric, the study's lead researcher at the Biology Centre of the Czech Academy of Sciences, added that it is important to note that the majority of species actually cannot become societally extinct, simply because they never had a societal presence to begin with.

"This is common in uncharismatic, small, cryptic, or inaccessible species, especially among invertebrates, plants, fungi and microorganisms - many of which are not yet formally described by scientists or known by humankind," Roll said. "They suffer declines and extinctions in silence, unseen by the people and societies."