Overestimation of extinction rates?

[LoisLane]

Hey there. What do you guys think about the Nature article saying we may have overestimated current extinction rates by as much as 160%? Has it been overblown? http://theconversati...ates-paper-2030

 

Hey there. What do you guys think about the Nature article saying we may have overestimated current extinction rates by as much as 160%? Has it been overblown? http://theconversati...ates-paper-2030

[CharonY]

Well, from that article:

 

“The rate of loss isn’t necessarily the same as the rate of discovery. That’s the point – and I stress, the ONLY point – of the He and Hubbell paper,” he told The Conversation.

 

“This isn’t a universal damnation of extinction rates, not by any stretch. All it says is in situations where the rates of extinction are based on accumulation curves only and where the species within are distributed patchily (as most species are at least at some spatial scale of measurement), in those cases you will overestimate the extinction rate. That’s all it says.”

 

Professor Bradshaw, who blogged about the paper on his website Conservation Bytes, said the paper’s conclusions had been blown out of proportion.

 

“The title is a bit unfortunate because, although strictly correct, you can read it uncritically and assume that all extinctions estimates are overestimates,” he said.

 

 

It basically calls for careful calibration of the estimates (at least I read that from it, I am no expert on that field).

[Chalky]

As I understand it, the paper can be paraphrased in over simplified manner as:

 

Consider a hypothetical example where a species has 10 members which live in a 10 km² area (for simplicity lets assume that they are evenly distributed).

 

Then we have 1 animal per 1 km2. So we only need to survey 1 km² to "discover" the species. However, to determine if the species is extinct, we need to examine the entire 10 km². So it is much easier to discover a species than to show it is extinct.

 

So mathematically the maximum overestimate of extinction might be 160%, but (without knowing more about ecology I can't really say) it is probably less.

[FarmForest Research]

The problem with extinction rates as we have not discovered many species so we really don't know what is going the way of the dodo. I worked on island biology and we do know the rate of extinctions on those places and they were rapid and final. If we look at large landmasses we have an inkling of where were going..as when we make national parks "Islands" within our land use. So we are probably correct in extinction rates..but when South Africa made corridors between parks as has Canada is some systems we allow a larger geographic and perhaps ecogenetic allowance.