Those of you who've come to one of my Scholarship preparation days may have noticed that I've got a bit of a bee in my bonnet about pseudoscience. It really annoys me when I see science being mis-used to sell a product or promote a particular point of view. A good friend of mine has just sent me one of the worst examples I've seen for a while, & I thought it could be useful to share it with you. Here's the lead-in to the article…
"Many scientists were stunned recently when it was revealed that air bubbles trapped in fossilized amber had been analyzed and found to contain oxygen levels of 38%. Yet today, it is well known that the average oxygen content of air is only 19% to 21%. In other words, since the early history of the earth, it appears there has been a whopping 50% drop in the average oxygen content of the air we breath! This discovery was particularly startling to researchers because it suggests that the human body was originally designed to grow and operate at a 50% stronger concentration of oxygen than what's currently available."
Gosh! How terrible! We're not getting enough oxygen!!!
OK, enough with the irony. But this really is a staggering misrepresentation of the facts. Yes, atmospheric oxygen levels did once reach 35-38% – in the Carboniferous period ie about 300 million years ago (relatively recently in the Earth's history – remember that this stretches back around 4.6 billion years). These high levels probably allowed the evolution of giant forms of many animals – insects and amphibians, for example.
And yes, oxygen levels have declined since then (there was a second, lower peak in the Cretaceous, about 80 mya). But they've been stable for the last 70 million years. (And in fact, with the exception of those 2 peaks, oxygen levels have been remarkably stable for the last 500 million years.) So, what about that claim that the human body was originally designed (& how I hate that term!) to grow and operate at a 50% stronger concentration of oxygen than what's currently available???
Ummm, when did humans evolve? The hominin lineage dates back only 6 million years or so. That is, we've always been exposed to an atmospheric oxygen content of 20%, throughout our evolutionary history. It's a total falsehood to suggest otherwise.
There's more. Much more. And I do intend to come back to it. But not right now – I need a sit-down and a good strong cup of tea after wading through that dreadful document!
PS a good book for you to read, if you're interested in things like oxygen levels and the role of plants in maintaining them, is this one: David Berling (2007) The Emerald Planet: how plants changed Earth's history. Oxford University Press. It's very well-written & presents a fascinating scientific story in a very accessible way. Enjoy!