Mass extinction theories

Imagine a fiery hole appearing one day in your backyard with temperatures topping 1,458 degrees Fahrenheit. This is a fire so intense that branches held near it spontaneously burst into flames. In Urumqi, China, this is exactly what happened recently.

The inferno appeared a week ago outside the village when a flaming sinkhole about a meter wide appeared in the ground. Scientists believe that the spontaneous combustion of coal may be responsible. They are exploring ways to close the fissure, but scientists warn it could reopen.

It was a fireball that made the news in Live Science recently. A report published in the "Monthly Notices of the Royal Astronomical Society" stated that the fireball that exploded over Russia in April 2014 was from an asteroid in the inner asteroid belt.

Scientists conjecture that some asteroids rotate rapidly, causing pieces of rock to fracture and stream out from the main body. No one knows for sure, but they were speculating this fireball was the result of such a release.

While the rocks are not necessarily large, they do pose local threats if they reach and explode in our atmosphere like this fireball did last April over Kola Peninsula.

While the asteroid that may have caused this Russian spectacle did not threaten life on our planet, another asteroid that collided with the Earth 65.5 million years ago off the coast of present-day Mexico may have been the dinosaur killer that wiped out the giant lizards from our planet. While the asteroid is long gone, its huge crater still survives submerged near the Yucatan Peninsula, and scientists want to understand more about the killer impact. They plan to drill into the crater and bring up a giant core from 5,000 feet below the surface.

They believe this would give them access to studying samples that are 10 million to 15 million years old. Such an ancient sample should give them key insights into what the asteroid did to the planet, how it affected the dinosaurs and what happened after the mass extinction. This project is slated to begin in 2016.

I found a related one about mass extinctions and came across an article about history's most mysterious extinctions; at the top of the list are Neanderthals.

The Neanderthal is a species of humanoid that thrived on the planet before the rise of modern humans. At one time we were taught that we are the descendants of the Neanderthals, but modern research has led scientists to believe that while similar in nature, we are a separate species and not related to the Neanderthals.

With the advent of finding miniature skeletons on the coast of Australia a few years ago, there is the current belief there may have been two to four species of humans coexisting on this planet some time in our distant past.

Why the others died out is a mystery, although there is some speculation as to what happened. Some competing theories include mass extinction, competition for resources, war or interbreeding.

The mass extinction theory is that Neanderthals were ill-equipped to survive when a massive volcanic eruption flung millions of tons of ash into the atmosphere, blocking out the sun and creating a cold, lifeless world for years. Scientists have learned this scenario is unlikely.

The modern theory is homo sapiens probably are responsible in one way or another for the extinction of Neanderthals. One idea is that humans declared war on Neanderthals and exterminated them, an ancient mass genocide. Another is that we just outmaneuvered them in the contest for resources.

There is another theory in which the interbreeding of Neanderthals and humans may have eventually caused them to be absorbed into modern human bloodlines.

I find the last theory the most compelling personally, even though there really is not evidence currently to support any of those three theories conclusively.

I remember reading an interview with Ozzy Osbourne, the infamous heavy metal rocker who played first with Black Sabbath and then had a successful solo career for decades. Osbourne was asked why he believed all the drinking and drugs he used had not killed him. He told the interviewer he sincerely believed it was because he is descended from a caveman.

As it turns out, according to an article in Scientific American, when Osbourne's DNA was submitted for genome sequencing, a short strand of Neanderthal DNA was discovered. Scientists have learned that some Asians and Europeans have a minute amount of Neanderthal sequences tucked away in their DNA.

This would tend to support the last theory that Neanderthals and modern humans interbred and perhaps made themselves extinct over several generations. This truth is far more complicated and interesting than we were probably taught in school. As you can see, science can be fascinating, mysterious and magical, and while I am critical about science avoiding some important questions, there is an important place for it in our lives, and its study can teach us so much.

Till next time …