Friday, August 31, 2007

Not So Extinct

I was one of many who lamented last month's echo of a proclamation in January 2007 that the Baiji, or Yangtze River Dolphin, was 'most-likely extinct.' Well, it seems like I should have respected the principle of scientific uncertainty a little more than I did. ScienceBlogger Zooilogix has posted a report that a Chinese factory owner filmed the dolphin on August 19, and a science daily article provides more details. One question I have is whether a private citizen's siting counts against the 50 year clock needed to announce 'definitive extinction.' I think the consensus is that this will merely delay the inevitable. I'll still stand by my opinion that the great leap forward set the environment several steps behind.

But this situation is a good case study of how scientists tend to choose their words carefully whenever certainty is concerned, but that this care is forsaken by mass media reports of the studies. The international commission charged with monitoring the status of the river dolphin used the phrase, "functionally extinct" to describe the baiji's plight. This followed a 6 week expedition at the end of 2006 to search for the dolphin. Another expedition in July made the same conclusion, and that two 'exhaustive' searched yielded no sightings was evidence to reinforce the original claim. "Functionally extinct" is a term that Wikipedia defines as
The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreeding depression and genetic drift, leading to a loss of fitness.
A good example of this is Lonesome George, the Galápagos Abingdon Island Tortoise, who is that species one known surviving individual, but is going strong as a 70 year old who can look forward to a 120 year lifespan.

Functionally extinct in the case of the baiji could mean isolation by dams or population dispersement in murky water or genetic inbreeding leading to loss of fitness. There is, in other words, a chance of slim to none that the species will recover to a sustainable population. If population biologists use the same criterion we use in biomedical science, slim means less than 5%. What concerns me is when public media (and bloggers outside their field) uncritically take 'very sure' to mean 'definitive.' That sets up situations like this one where those same media outlets (or worse, anti-science interest groups) can point to an outlier or other counterexample and say, "See, those scientists don't know what they are talking about!"

I still want an answer to my question above concerning the 50 year rule, but we all should question how it is that the practice and language of science can be better represented by the media.

3 comments:

Mark Powell said...

Suggested you to my readers on blog day, hope your server doesn't crash when both my readers drop by

Dorid said...

LOL... looks like I'm the first coming from Mark's page ;)

what makes me sick about all this is that I've read news reports saying things like, "If there's one, there has to be three. If there's even two, we can bring back the species."

I don't understand what the excitement is over seeing ONE Baiji. Seems to me the BEST it could do is launch another expedition to see if they can find any more.

Anonymous said...

Genetic viability of a species, requires something on the order of 100 unrelated individuals, os finding one or a a few does not mean much if anything -- except to those animals, of course!

Still, can you imagine what it would be like to be the single surviving member of a highly intelligent species like dolphins?

This one almost certainly has memories of days gone by swimming and frolicking with family members.

What a cruel existence that would be to spend the rest of one's days looking for lost relatives and never finding them.

Breaks my heart to think of it.