Environmental challenges: a life scientist's perspective

Such prosperity as we have known it up to the present is the consequence of rapidly spending the planet's irreplaceable capital. Aldous Huxley

Our ideals, laws and customs should be based on the proposition that each generation in turn becomes the custodian rather than the owner of our natural resources. Alden Whitman

As a postgraduate student I did my research at Oxford in the Tinbergen building (named after the famous zoologist Nicholas Tinbergen who studied bird behaviour). Although I was then a biophysicist, the majority of the workers in that building were zoologists and I was soon being alerted (and indeed recruited) to ecological protest. At that time alarm about man-made environmental damage was high. Rachel Carson's classic book Silent Spring carried a warning about man's indiscriminate use of pesticides. In 1972 the Ecologist Magazine published its "Blueprint for Survival" which became a catalyst for spurring many different environmental groups into action. It was so significant that half a million copies were sold and it was brought out as a book. Planned to hit the newsstands before the 1972 UN Stockholm Conference on the Human Environment,the Blueprint for Survival remains a clear outline of global environmental issues we face right now. This eventually led amongst other things in the political area to the formation of the Green Party.

Forty years later, one controversial Blueprint claim seems eerily accurate: " that were [global] confidence to fall, stock values would crash, drastically reducing the availability of capital for investment and hence further growth, which would lead to further unemployment". Even this spectre didn't seem to galvanise governments into action at the time. In 2021 now that we have added global warming to the impending ecological challenges, administrations finally seem to be waking up to the inevitable: real action rather than just summits has become urgent.

What as a life scientist forty years on from the "Blueprint" do I have to contribute to this? Well I believe that evolutionary biology will take over from us in determining our future, but we could direct this even if we cannot divert it. As a cognitive species we have choices denied to other species on planet earth. When I worked in a biotechnology company (Delta Biotech in Nottingham) the head of fermentation science showed me round his lab and his replies to my questions seem so relevant today:

Steve: These yeast fermenters are closed systems as far as the yeast's concerned: we never take any out. We aim to achieve as much growth as fast as possible. To do this we supply the culture [the living yeast cells] with oxygen and nutrients and regulate the pH and metabolites [acidity and waste products] and temperature closely. Too hot or cold, the yeast will stop growing, get sick and die. Not enough nutrients or too much waste product, obviously the same thing will happen and if the pH goes too low the culture will die too.
Me: What happens in the end?
Steve: The yeast cells will grow until they crowd each other out [overgrowth], but generally before that happens even under the best controlled conditions we can't maintain the temperature evenly enough, control waste products or supply oxygen or nutrients fast enough to sustain the culture so it stops growing and dies. Always.
Me: Could you keep the yeast culture alive?
Steve: Of course! We could continually remove cells from the culture, but then we wouldn't have a closed system would we? Plus it would be uneconomic. This is business, not ecology!

Humans live in just such a closed system (unless you count our efforts in space). We know there are "limits to growth" it's just that we have argued endlessly about what these are! The lesson we can take from Steve's laboratory yeast fermentation is that, through unchecked growth (procreative and economic), we will eventually run out of space, nutrients, survivable temperatures and environment as well as feasible economic activity for all (Steve's yeast cells are working for their living like us). Unlike yeasts and other single celled micro-organisms our generation time is measured in years, not minutes which leaves us far less able (through our biology) as a species to adapt to a changing environment. Changes to our environment which take place on this timescale leave us highly vulnerable. The plant kingdom too cannot adapt rapidly to climate change; especially the high intensity crop staples upon which we absolutely depend. Without positive action over the coming years, lifespans will decrease, quality of life will go down and in many parts of the world even more of us will sicken and die.

Micrograph of yeast cells: like most micro-organisms it can evolve quickly through mutation

But I believe before we arrive at this dystopian outcome, evolutionary biology will make accelerated adjustments to life on earth. This will be most apparent in micro-organisms. These life forms are the most plastic (adaptable) on earth. Some types of bacteria thrive even now in extreme environments which could support no other form of life: temperatures at or above 100 degrees C, very high salt concentrations, high radiation levels and in the absence of oxygen to name just a few. It is becoming apparent that even in higher animals evolutionary adaptations can take place much more quickly than once thought.

Unlike most other forms of life, from the beginning of "civilisation" we humans uniquely have had to rely on our technology to overcome both medical and environmental problems. We will continue to do just that. We might even consider our technology to have a genetic basis as Richard Dawkins argues in his book The Extended Phenotype. Dawkins has famously claimed that the most valuable component of all life is DNA: our genes and these are indifferent to the nature of the "survival machines" that carry them! Kevin Kelly in his work What Technology Wants even explores the controversial idea of technology gaining a "life" of its own! The dystopia in Kevin's future projection is that human life forms may reach a point where technology becomes our master or even our successor instead of our assistant!

We still have many surprises to learn from biological evolution as well as the evolution of technology. It seems that birds, in regions where average temperatures have substantially increased, are becoming smaller in response to rising global temperatures. Birds are shrinking! Living at elevated temperatures, a smaller body has an advantage. Its larger surface to volume ratio alows its body to cool more quickly. That small difference can lead to positive selection of smaller and hence "fitter birds".

Essentially all the life forms with which we share our own closed system (earth) are in ecological balance to a greater or less degree. All life forms (even viruses if you want to include them!) are in a constant arms race: predator vs prey or life form vs environmental change. This has tended to keep a balance in nature that has persisted from long before humans came on the scene. Although we have caused many extinctions, some of which may prove greatly to our loss, many species, especially the micro-organisms already mentioned, have survived successfully on earth from back in deep time. Extinction over time of a particular species isn't inevitable - just quite likely!

So, before we reach an environmental "event horizon" from which even with our technology, it's impossible to escape; are we going to follow in the path of Steve's terminal yeast cultures, take control of our destiny by becoming a well adapted "continuous culture" or are we just going to leave it to evolution to decide our ultimate fate?

Other relevant links


The Extended Phenotype. Richard Dawkins (1999) Oxford University Press
What Technology Wants. Kevin Kelly (2011) Penguin Books