How far are we from extinction? What will take our place? Grisly prospect, isn’t it? But it will happen if the past is the best indicator of the future. E.O. Wilson, hailed as a genius of nuclear science, claims that by the year 2100, half of the plant and animal species known today could be extinct. It is a scientific fact that approximately one thousand species disappear each year. That falls in a median range of about a five hundred percent acceleration over the norm; not enough to prove a mass extinction looms, but certainly more than enough to make one alert to the possibility.
Back to the best indicator…, Not quite ready to go the way of the mastodon, I decided to take a look at the history of mass extinctions. I was concerned to note that they happen at rather regular intervals and interested to note that a new order has become dominate after each incident. To put it in proper perspective, five hundred seventy million years ago, there were no humans, but there were snails. Four hundred million years ago, fish were the predominate life form. There have been five or six major extinctions noted by scientists.. After each one a new life form emerged predominate..
The mastodon is a pretty good starting point. Having come into existence about twenty-five million years after the demise of the dinosaur, there is a good amount of information to help form a perspective. There used to be seven genera (plural of genus) of mastodons and mammoths in the order Proboscidea. Today only two of those exist. They are the African elephant and the Asian elephant. While the Proboscids are known to have existed some sixty-five million years ago, it was about sixty million years ago that the first to bear a slight resemblance to today’s elephant existed in the form of a pig sized animal with a trunk.
Around the same time there emerged a Paleomastodon, not to be confused with a mastodon, that lived in Africa. It was a mere fifteen million years ago that the mastodons began roaming North America. And where are they now?
As mentioned, contrary to the concept promoted by popular movies, the dinosaurs had been extinct for almost twenty-five million years before the appearance of the first mastodon. There are many theories as to why the dinosaurs went extinct, but their and many eras of extinction were thought to have occurred after a comet or an asteroid impacted Earth.
About two hundred million years ago all the land of Earth was amassed in one super continent called Pangaea. The break up is thought to have been caused by a large comet crashing into the surface. By using different isotopes scientists have been able to date the age of rocks and also to measure the amount of life on Earth at that time by measuring the carbon levels. They have also noted that the decline of carbon levels correlated directly with the decline in radiolarians, a main component in the food of a vast number of marine species. This period of extinction is claimed by scientists to have killed off ninety-eight percent of the species.
Fast forward to the post Jurassic age. Again there is evidence of a collision between an asteroid or comet and the earth. In all cases of mass extinction that have been studied, the same process has been noted. It can be stated quite simply as “long-term stress compounded by a short-term shock.”
The dinosaurs had survived for roughly one hundred and sixty million years. Could it be that the long term stress was created by an abundance of the same species creating a drain on the same elements of the environment? I say yes, but even so, they probably would have survived until ‘short-term shock’ was introduced into the equation. That shock being the collision of earth and comet and the residual effects.
Richard Firestone, a nuclear expert, has been working for years now on the hypothesis that the North American megafauna (mastodons, wooly mammoths, etc) went extinct due to a supernova.These cataclysmic events, including volcanic eruptions and earthquakes, supernovas, and like events, release greenhouse gases which are a combination of water vapor and carbon dioxide. They are so called because they trap heat from the sun and that warms the earth’s surface. Without them the earth’s surface would be a frozen mass. There is always variation in the greenhouse effect. Those species that can not adapt become extinct.
There is methane in the silt at the bottom of the seas. One of the major sources would be the decaying carcasses of marine life. A release of that methane creates a bubbling effect that depletes the sea of oxygen. Interestingly enough, the same event might cause both global warming or global cooling. When an event causes the explosion of methane, there will be fires that produce lots of smoke and ash. The same is true in a volcanic eruption. That ash and smoke would block the sun and lead to a great cooling. It would be rather temporary as the elements would wash the air clean again in a short time. It is then that the raised levels of methane and carbon dioxide would do their dirty deeds. We would see years of extremes in both directions…from unbearably cold to unbearably hot. The constant fluctuation would lead to a massive failure of crops, which would lead to global famine. The chain is self sustaining and lethal
Of course all these theories are just that…theories. If one were a fatalist, it seems clear there is evidence to support imminent extinction of the human species. It seems equally as clear that it will be replaced by another more adaptable species, just as mammals replaced reptiles as the predominant species during this, the Quaternary Epoch of the Cenozoic Era. Another point to remember is that after the mass extinction of the dinosaurs, a few of the strong survived, and after the extinction of the mastodons, a few of the strong survived. In each case those survivors perished at the hand of human hunters.
So, what are the lessons here? When I started out, I was looking for a way to stay the extinction. I believe it relates to green house gases, to long-term stress and short-term shock and I believe there is, waiting in the wings, a species that will adapt. I think the hole in the ozone is just a minute factor in a chain created by Nature herself. If we could super glue a patch on it today, the possibility of extinction is unlikely to change. History shows us that it is a cycle that leads to a higher development. I think the greatest lesson of history is to live with compassion and to pray hard that those of the next era have a higher compassion.
foot note: It should be noted that in scientific terms an ‘imminent extinction” encompasses a time frame of roughly ten thousand years. The dinosaurs became extinct over a period of about ten thousand years, and the mastodons are thought to have taken about twelve thousand years to disappear. That is barely a blip on the timeline of eternity, but no matter what the doomsayers say it is ample time to become the best we can be.