The near wipeout

Modeling, proofs, and science’s value

I hope it has been a satisfying summer. I realise for many the heat spoiled it but this is the new normal, it would appear, so it was a wake up call that our lives will change from here. It was also a summer of some surprises as well as some revisiting of the recent past. But, it has reached its bittersweet end as schools resume across the northern hemisphere in this period.

I want to close the summer discussing a truly mind numbing analysis this week. As so often the case, it harboured a caution and hope. Yet it strikes me so many variables beyond our control—beyond our control is not something we like to hear—could have led to an outcome far less salutary but that is just my thought on consequences. But, I am getting the cart well, well before the horse.

According to a study pushed yesterday in the reputable journal Science, the population of our species dropped to a mere 1,280 individuals on this beautiful speck in the middle of the deep blue skies 930,000 years ago. One thousand two hundred eighty. I read through the abstract of the article as well as a comment from a scholar at the esteemed British Natural History Museum so I confirm the number cited is not a misprint. The study published yesterday showed a incredibly tiny number, especially on a planet now hosting more than 8 billion individuals.

Michigan Stadium, ‘The Big House’, holds more than 100,000 folks screaming ‘Go Blue’ on a football Saturday so this would be one tenth that number on the entire planet if borne out. The incoming class at West Point in late June was 1,190, almost this same figure. Saline, down the road from Andrew Carnegie’s birthplace Dunfermline, is a Fife village which had 1235 residents in 1990 but decreased to a mere 1180 souls as of 2020, one of countless welcoming but diminutive Scottish communities. A particularly macabre comparison is to opioid deaths in this country which average 136 daily: the number of humans this study projected would have been wiped out in ten days by those numbers.

James Ashworth of the National Historical Museum in London accessed the entire article. He noted the authors listed possible causes as climate change (a known extreme cold spell at that time), disease and natural disasters for creating an evolutionary ‘bottleneck’ in human reproduction that lasted about 112,000 years. Ashworth also reminded lay folks this is a study that coincides with questions about a gap in fossils in Africa from that era. Pretty stern stuff.

The study bases its results samples on human genomes, factoring them into the mathematical modeling increasingly available to scientists. I have mentioned my son, the evolutionary biologist, does this exact modeling on prairie grasses after fires. The data sets are pretty small samples but then plugged into massive programs run on supercomputers for extended periods of time.

The story appeared in Science only yesterday. It will guarantee rebuttals and re-examination of the hypotheses, the data, and the logic of how the team examined their subject. And reexaminations of the reexaminations. That is how science works. These published results must stand the test of their peers replicating their outcomes. Science is brutal to inconclusive or imprecise results as the authors of cold fusion found in 1990 when their theory failed the test of reproducing its results.

The 930,000 year time distance from today will also raise many hackles as almost a million years back seems hard to prove much. But this is the beauty of science as well: its rigors force those who engage with it to refine, then prove the hypotheses, then see that the processes used stand up to reconsiderations. It is not an arbitrary deal.

What a sense of accomplishment Andrew Wiles had to feel after he went through these steps three decades ago. The British mathematician solved one of the most enduring, seemingly insoluble problems in his field by unveiling a proof of Fermat’s Last Theorem on elliptical curves, a problem postulated in 1637. Wiles offered his initial solution in 1993. Examination by an amazed and almost giddy (mathematicians get worked up about some things the rest of us cannot fathom) peers showed an error in his work the following year. By 1995, Wiles resolved the error, republished his proof, stood back as peers tested it, and ultimately took his position in the pantheon of geniuses in an extremely abstract field. He also received a knighthood but I doubt that compared with the satisfaction of solving something that held up to the scrutiny of so many and had been one of the biggest questions in math for three centuries.

Time will tell whether this recent theory holds up and whether it is acceptable in our era of unflinching doubt. From reading the abstract (paywalled article), the paper does not address how the climate change issue or anything else caused this bottleneck but Ashworth indicates the authors opened doors in this area which others might pursue.

It is remarkable, if true, that the human population could have been so tiny yet rebounded to today’s numbers. We should not automatically assume the data is wrong because we cannot see the Actions Creating Consequences. Consequences are sometimes quite apparent and sometimes take so long to manifest that we forget the initial action ever transpired.

I wanted to close this week with this story because its shows the redeeming feature of the scientific method and the indomitable spirit of those who engage in inquiry. One of the things that vaulted the United States into the position we have held as THE scientific superpower for a century was the willingness to push science through honest, peer-reviewed processes in so many disciplines. John Barry’s marvelous study of the 1918 pandemic, The Great Influenza, was so important because it not only told the forgotten tale of the spread of the ‘Spanish flu’ after World War I but paralleled that history with discussing how scientists primarily at Johns Hopkins University in Baltimore used rigorous methods to test solutions to understand and combat the flu’s spread. It was a key triumph from that horrible experience.

Yet science and rigorous methods seem increasingly casualties in our twenty-first century America. Tales of scientific impropriety, shoddy methods, and conflicts-of-interest dot discussions, contributing to yet one more casualty in trust for institutions. Simply getting students proficient in math, science, and logical thinking is a national quest on which we have been failing for decades (I acknowledge I am hardly one to talk about mastering math or science). I am not sure we need more money for science (although I am thinking of countless areas where more research would be welcome) but we definitely need a new generation of Americans proficient to study science and its methodology and various questions. Without those inquiries, the chances of human error and defaulting to ideas often fundamentally wrong could have disastrous consequences for all. We are not alone in this as Americans but we only control our own system so we must create incentives for younger students to embrace a bigger role in that scientific system. Outsourcing math and science to researchers elsewhere is a recipe for a true supply chain catastrophe of a different type than most often recognized.

Have a safe holiday weekend. Thank you for the comments on yesterday’s column and I appreciate you reading today’s. Please feel free to circulate or restock (button below) if you think someone else would enjoy Actions Create Consequences. Be well. FIN

James Ashworth, ‘Human ancestors may have died out after ancient population crash’, Nhm.ac.uk, 31 August 2023, retrieved at https://www.nhm.ac.uk/discover/news/2023/august/human-ancestors-may-have-almost-died-out-ancient-population-crash.html

John Barry, The Great Influenza: The Story of the Deadliest Pandemic In History. New York: Random House, 2005.

National Center for Drug Abuse Statistics, ‘Drug Overdose Death Rates’, retrieved at https://drug abuse statistics.org/drug-overdose deaths/

‘The Proof of Fermat’s Last Theorem’, retrieved at https://web.archive.org/web/20081210102243/http://cgd.best.vwh.net/home/flt/flt08.htm

Wangjie Hu, Ziqian Hoa, Pengyuan Du, Fabio di Vincenzo, Giorgio Manzi, Jialong Cui, Yun-Xin Fu, Yi-Hsuan Pan, and Haiphong Li, ‘Genomic Interference of a Severe Human Bottleneck During the Early to Middle Pleistocene Transition’, Science.org, 31 August 2023, retrieved at https://www.science.org/doi/10.1126/science.abq7487