Note: Please post only extinction event comments below.
The Sixth Extinction
There have been five major extinctions in the earth’s history and twenty lesser extinction events. They are all cataloged by Wikipedia here:
And here, below, are all the extinction events since the KT extinction.
The event 2 million years ago was, of course, the start of the ice ages. However, there is some who say that it was ushered in with an asteroid impact.
I am not prepared to comment one way or the other on this bit of news. However, their explanation for the Quaternary extinction event is interesting. There were three events which they say the causes were unknown but may indicate climate change or overhunting. Really now? Let’s look at the first two dates.
640,000 years ago. This is the exact date that geologists and volcanologists estimate the Yellowstone supervolcano erupted.
74,000 years ago. This is the exact date that geologists and volcanologists estimate the Toba supervolcano erupted.
One would think that if there were two spikes in the extinction rate at the exact same time two super volcanos erupted, that they just might put two and two together and figure out that these two supervolcano eruptions had something to do with it. The Toba eruption almost wiped out the human population leaving, by some estimates, less than 10,000 humans alive.
And now the extinction event of 13,000 years ago has been explained. It was actually 12,900 years ago. It is all explained in this Nova presentation The Last Extinction . An extraterrestrial meteorite or asteroid impact was the culprit. Thanks to GoneFishing for the link.
Note: If you are really interested in the Pleistocene or Ice Age extinction, then you should read this Wiki page. Quaternary extinction event It gives the name of the megafauna species that went extinct during the early, middle and late Pleistocene.
The chart below, found at Images of Mass Extinctions, gives the percentage of Genera that went extinct during each mass extinction. Genera, plural for genus, is a taxonomic rank just above species and below family usually consisting of more than one species. Some genera of insects may consist of hundreds of species.
Though the KT extinction appears deeper than the Permian extinction. However, only 47% of all genera went extinct during the KT extinction while the Permian extinction wiped out 84% of all genera. That is because almost twice as many genera existed prior to the KT extinction.
But what about the current ongoing Holocene extinction, or the Sixth extinction or the Anthropocene extinction? Anthropocene, the age of man. What is causing that?
The first two charts below were created by Paul Chefurka from data published by Vaclav Smile in this 24-page PDF file. Harvesting the Biosphere: The Human Impact
This chart shows world terrestrial vertebrate biomass 10,000 years ago and today. That is all land-based vertebrates including birds. Note this is not the number of genera or species but total terrestrial vertebrate mass. In any extinction, the large animals are always the first to go. So even though there has been a huge decline in the number of surviving species, the large animals have suffered far greater than the smaller ones. Also, this chart represents surviving wild terrestrial vertebrate mass, not the number of surviving species.
But my point is what caused this? What caused the amount of wild vertebrate biomass to go from 99.9% 10,000 years ago to less than 3% today? And it is about to get a lot worse.
The U.N. estimates there will be 9.72 billion people in 2050 as opposed to the 6.2 billion in 2000 as represented above, and of course, our domestic animals will have increased by a like amount. So, in 2050 the wild terrestrial vertebrate biomass will be less than 1% of the total.
So, what’s causing the disappearance of wild animals? Do you think that maybe, just maybe, that the increase of the red and blue biomass has something to do with the disappearance of the green, or wild animal biomass? Do you think? Or do you think the wild animal collapse had little to do with humans overrunning the earth?
No, hell no, we are the cause of this sixth extinction. That’s why they call it the Anthropocene extinction.
I cannot locate an animal population chart but if I could I am sure it would look like this one below except it would be turned upside down.
But I did find this one which shows not just terrestrial extinctions but freshwater and saltwater extinctions as well.
52% of the world’s wildlife species disappeared in just 40 years. Source: World Wildlife Fund. And this does not include the species that were wiped out before 1970 or those that have gone extinct since 2010.
Keep in mind that the Paul Chefurka charts above represent total terrestrial vertebrate biomass, not species. A species can still survive even though their numbers, and total biomass, is just a percentage point or two of what it was a few thousand years ago. But when that happens you know it is on the cusp of extinction. Anyway, here is what caused it:
Every cause there except the smallest one, disease, was caused by humans and their domestic animals. And I am not so sure about that one. If we starve them out, they are far more susceptible to disease.
Hey, it’s just common sense. Whenever humans and our domestic animals take over the territory of other wild animals, those wild animals just have to go. End of story. We are the Colossus, the super-predator. We have the power to just take over their territory for cutting it for timber, or for farming and draining all its water for irrigation, or for building cities and highways, or for whatever, so we do. We Homo sapiens are the cause of the Anthropocene extinction and there is no other cause.
Go here if you dare. Bushmeat Images
We have met the enemy and he is us.
Hey, it’s just common sense. Whenever humans and our domestic animals take over the territory of other wild animals, the wild animals just have to go.
There is no green solution that will save the animals. End of story.