By Doyle Irvin, American Forests
There have been five major extinction events since the dawn of our planet’s history, with the earliest occurring 440 million years ago. The end of the Cretaceous era 66 million years ago marks the most recent wipeout, but many scientists are now arguing that we are in the middle of the 6th major extinction of life on Earth.
The evidence for this is staggering — for example, the “natural” extinction rate, without human intervention, is roughly one to five species a year. Studies currently state that 1,000 to 10,000 species are disappearing every year, and that as many as 50 percent could be extinguished by the middle of the 21st century.
That this would not make it the most devastating extinction in history is no relief. Ninety-six percent of life on Earth died out 251 million years ago after an enormous explosion in what is now Siberia. This explosion launched massive amounts of carbon dioxide into the atmosphere, drastically altering the bacterial makeup of the biosphere, which began pumping out methane at lethal levels. The oceans thus became acidic, and started to emit hydrogen sulfide. All of these factors together contributed to what has become known as “the Great Dying.”
We use the example of the Great Dying for multiple reasons. First, each reaction in turn catalyzed the next, displaying how easily one event — say, an excess of carbon in the atmosphere — can spur the next, more drastic reaction. Second, we cite the Great Dying because it is inspiring, in a particularly morbid kind of way, that all the subsequent life on Earth evolved from the scant 4% that survived that event. Life finds a way. Lastly, we cite the Great Dying because, even though some species survived and eventually gave rise to the planet we have today, the extinction event set back life on Earth by about 300 million years.
That time span is beyond biblical in proportion, and equally beyond the easy comprehension of human minds. More comprehensible, and especially relevant to this article, is the story of the Judean date palm. Prominently featured in the Old Testament and other contemporaneous works, we know that the Judean date palm was a cornerstone of the economy in the Levant for roughly 1,500 years. Forests of the trees covered the Kingdom of Judea and fed its citizens. The Romans, correctly understanding the trees to be a keystone for the Judeans, promptly began destroying the trees, as means of conquest, and by 500 C.E., the date palms were driven extinct.
Was that the end of the story for the Judean date palm? Relegated to the annals of history and scriptures? No, it was not the end: life finds a way. Excavations during the 1960s of Herod the Great’s palace uncovered a stash of seeds stored in a clay jar for the last two millennia. They were then put into a drawer for the next four decades, until, in 2005, scientist Elaine Solowey made the decision to plant one — just to see what would happen. Ten years later she updated the world, letting us know that the tree was a dad, successfully pollinating female date trees of other species. Some more of the ancient seeds had also by then been sprouted and identified as female, meaning that a pure strain of this ancient tree could soon be in the works.
Not to be outdone by the Israelis, a team of Russian scientists discovered 32,000-year-old seeds buried under 124 feet of permafrost. Initially failing to germinate them, the scientists then took cells from the placenta of the seeds and grew the Silene stenophylla from a petri dish into an entire, intact flower.
How is this relevant? As we said earlier, human actions have placed the planet squarely into the middle of a sixth extinction. Recent studies have shown that more than 300 tree species are critically endangered, with fewer than 50 representatives of their species remaining. They also state that more than 9,000 additional tree species are threatened by extinction. But, as the examples of the Judean Date Palm and the Silene stenophylla tell us, the story isn’t over yet.
Human intervention restarted these two ancient inhabitants of Earth: life finds a way. We just have to remember that we are life, and we must find the way.