Something New to Appreciate Planet Earth For

I learned something new today. There is a good deal of evidence that 650 million years ago this planet underwent the worst ice age it has ever seen. An ice age that covered the entire planet, from pole to pole in a solid sheet of ice up to 1,000 feet thick.

We enter an ice age roughly every 100,000 years. Generally they follow the same story. The earth's orbit slowly takes it further and further away from the sun, gradually dropping temperatures globally. The polar ice caps begin to spread toward the equator, though they never get there. They always stop quite a distance away as the planet slowly returns to its position nearer to the sun. But this ice age was different. Not only was the planet further from the sun, it also, through various reasons that would take too long to explain here, was losing vast quantities of CO2 out of the atmosphere, locking it in limestone deposits beneath the ocean. CO2, a greenhouse gas, normally helps the atmosphere warm and retain heat. So much was being stripped from the atmosphere temperatures plummeted. The ice spread from the poles much faster than it ever had before, or has since.

And here's the wild part. Snow covered glacial ice is the best reflector of the suns rays on the planet, reflecting nearly all of the sun's energy back into space. Ocean water is the poorest reflector, absorbing far more heat than it reflects back. So as the glaciers spread across the planet, glacial ice replacing ocean water, the planet reflected more and more heat back into space. Eventually it reached a critical mass, creating a runaway, self-perpetuating cooling event. The less liquid water there was the less heat the planet retained cooling the planet further, creating more ice, which replaced even more of the liquid water. In no time (cosmically speaking) earth was completely locked in ice, a giant snowball hurtling around a sun that was powerless to help it.

The planet stayed like that for millions of years. Eventually volcanic activity below earth's surface, which ebbs and flows entered a very active period. Over a span of about a million years volcanoes, which emit large quantities of CO2, gave off enough of the greenhouse gas to get the planet warming again. And as more ice melted and more water was released the planet retained more heat and thawed ever faster. Eventually the ice age to end all ice ages was over.

Now here's the really cool part. Before this global freeze life had been evolving on the planet for nearly three billion years. And in that time it hadn't gotten beyond single-celled organisms. These organisms were trapped below (and in) the ice. They either had to adapt or die. Those that did survive were truly the heartiest of the hearty. The cream of the genetic coffee. When the ice finally melted the earth saw the biggest boom in evolution that had ever occurred. It helped that the chemistry involved in a global, prolonged freeze / thaw created more oxygen than had ever existed in the atmosphere before (oxygen levels in the air went from 1% to %20). The hearty survivors of the global ice holocaust, in the newly-created, oxygen rich world went wild. For the first time in three billion years multi-cellular creatures appeared. And in what is called the Cambrian Explosion, multi-cellular life...exploded. After three billion years of stagnancy, huge numbers of complex life forms begin appearing in the fossil record over a period of only 80 million years.

The global freeze had the potential to wipe out all life, such as it was, on earth. Instead it ended up kick-starting evolution, creating a massive diversity of life forms that eventually led to us. It's very possible that had this massive ice age never occurred earth would still be a planet dominated by single cell "slime" life. So give thanks to the universe's unforgiving nature. Had it been kinder to our planet we'd likely not be here.

The Progression of Biology

I was just thinking about biologists. None specifically. Biologists as a career path. I was thinking about how their focus has slowly changed over the years. I love the fact that science is a living, evolving practice, shaped both by its own discoveries, and by the environment it functions inside of.

Here's my take on the shifting role of biologists. As a young science, biology was mainly concerned with discovery. Finding and identifying new species, learning about the basic functioning of elaborate ecosystems, and understanding how animals and plants adapt to their surroundings. Biology was all about filling in the holes in our basic understanding of our living world, a science devoted to learning about things because they were there.

Slowly though, as human activities began to adversely affect our planet, a large swath of biologists switched from pure understanding to conservation. How do we save the great biodiversity our planet spent millions of years cooking up? We now needed to understand exactly how our activities impacted our environment, and how we could mitigate some of the damage. Biology matured, and a purpose was tagged onto a search for understanding which was, up until that point, for it's own sake. And this aspect of the science of life has become even more desperate and personal as we've realized how much a part of our ecosystem we are, and how our impact on the planet is beginning to adversely affect us.

While this shift is going on, technology advances. Discoveries are made across many different disciplines which have lasting affects on the practice of science. Biologists, armed with the constantly improving tools genomics provides, are moving slowly from a passive stance, simply studying life as it is, to a much more active mentality, modifying live to certain ends, and eventually creating custom life. That, to me, is a very interesting paradigm shift, because it marks the moment we move from just studying life with technology to life becoming the technology.

That, I think, is where the science of biology is ultimately taking us. A fusion of life and technology. Life as technology and life merged with inorganic technology. The fusing of robotics and computer science with biology. Cyborgs, if you will. Biology enhanced by circuitry and physical technology. And biological computing, using cells and proteins to create computer systems able to grow and evolve. Artificial brains, in a sense. It's a merging of all available technologies to improve human existence.

And it's not selfish. The evolution of the study of biology is ultimately caused by our deep concern for life. At a basic level want to learn about it, know its inner-most functions intimately, and deeply understand processes once unfathomable. When these systems are threatened we move to protect them, also because of our innate concern for life. And the more deeply we understand life, the more we appreciate how important it is to protect it. And once safe, our concern drives us to improve life. To learn new ways to repair it and heal illness. To amplify its natural abilities for positive ends. To fuse all available technologies into its structures, all in an effort to make life on this planet more robust, healthier and more positive for ourselves and our co-inhabitants.

The study of life has become a study of the planet as a whole, our place in it, and how best to continue that existence, in both senses of the phrase.

The Resilience of Life

During the Permian Extinction, a mass extinction event which occurred roughly 251 million years ago, 96% of marine species were lost and 70% of vertebrate land-dwelling species were killed. It was the worst mass extinction the planet has ever seen.

And yet, here we are.

The Permian Extinction is by far the worst extinction event the planet has ever seen, but it's by no means the only. The most recent, which occurred 65 million years ago, wiped out the dinosaurs. There have been five major extinction events since life first percolated in earth's primordial seas, and many other smaller events. In total 99% of the species that have ever existed on earth are now extinct.

But life still flourishes.

I like to remember that when I start worrying about mankind's impact on the planet. We can do, and are actively doing a lot of damage to earth's ecosystem, and if we don't get ourselves in check it's just going to get worse. But even if we manage to pull off destruction on the scale of the Permian Extinction, which would be very difficult, life would manage to soldier on and reblossom after we're gone.

Please don't misunderstand. I'm not trying to provide an excuse for inaction. As a species we have unprecedented power over the well-being of our planet. We need to be good stewards of the world that birthed and sustains us, if not for its sake, than for ours. Continuing down our current path leads nowhere good. If we're not careful our species could end up on the pointy end of major mass extinction event number six.

But my point is that, even if this happens, life will rebound and repopulate with new forms and shapes we can't imagine. Life will continue to exist.

Until the sun supernovas and earth is swallowed whole. But that mother-of-all mass extinctions is a long way off.