The 99% Extinction

I wanted to add this news topic in my last post but then thought I needed to learn more to understand the new findings better.

Here’s the link to the article with the provocative title that caught my eye: “Humans nearly went extinct 800,000 years ago”.

Here’s another article that provides a little more scientific detail on the findings: “Extreme cold may have nearly wiped out human ancestors 900,000 years ago”.

Briefly, some scientists in US, Italy and China deployed some kind of DNA method, which I won’t go into details (as if I could explain it, ha, ha), that led them to the theory that the human race was hanging by a thread 800,000 to 900,000 years ago. The human population crashed about 900,000 years ago from 98+K individuals down to 1,280 individuals. This “bottleneck” remained for roughly 117K years before growing again to roughly 27+K about 800,000 years ago.

So, roughly hardy 1,280 individuals were able to survive during that 117K years span until human could propagate again. That is already astonishing to think that humanity relied on a small number of humans.

This story of the bottleneck fits the current fossil record: there are very few fossil records from that era, so the conclusion from the new scientific DNA method seems to dovetail with the fossil records – or lack thereof.

But what really caught my attention was why the population crashed: climate change!

Instead of warming though, it was the Ice Age, with periods of warming and cooling. The Pleistocene period, which ranged from 2.58 million years ago to 11,700 (Wikipedia), had glacials and interglacials (warming eras). The glaciation would suck up a lot of water, contributing to falling sea levels and decreasing rainfalls, leading to droughts. Not only human population crashed but other species suffered declines as well due to the droughts.

The story of population crash from climate change made me wonder about our climate change. Will we suffer a population crash during the ensuing decades? We’ll have fires, droughts, flooding, extreme heat, all of which will kill people. I don’t know…nobody talks about this, but it could be a possibility.

It could be we are not talking about this because we don’t really know and it is already hard enough to convince the climate deniers that climate change is happening now, never mind talking about a population crash.

“If you haven’t been convinced so far, then I will let the future convince you because the future is going to convince you.” – Hank Green

One caveat though: the findings need to be tested in the scientific community. Other data and scientific methods need to support this theory of the crash before it becomes accepted amongst the scientific community. We are at the very beginning of the testing phase within the science community.

But it is a very interesting and troubling theory.