On Wed, Mar 12, 2014 at 11:40 AM, Chris de Morsella <[email protected]>wrote:
> > >> >> 66 million years ago 2/3 of all species, not individual animals but >> entire species, became extinct quite literally overnight, and 252 million >> years ago it was even worse, the extinction rate was 90%. What we're >> experiencing now is not even a burp. >> > > > You do not know that those extinction events happened overnight - in fact > you are wrong on that. The asteroid may have impacted off of the Yucatan > overnight, but it could have taken decades and even hundreds of years to > play out, > Worldwide it was dark as pitch for at least a year after the asteroid hit and photosynthesis, the engine room of the entire ecology, was completely shut down during that time; the surprising thing is that only 2/3 of all species went extinct. And I made a error in the above, the correct figure for the Permian extinction 252 million years ago is not 90%, it's closer to 96%. > the current rate of species extinction - going on right now in our > contemporary times - is around 10,000 times the average background rate > [...] the data supports the claim that the current extinction rate is > around 10,000 times the usual levels > I quote from Wikipedia: "The fact that we do not currently know the total number of species, in the past nor the present, makes it very difficult to accurately calculate the non-anthropogenically influenced extinction rates. As a rate, it is essential to know not just the number of extinctions, but also the number of non-extinctions. This fact, coupled with the fact that the rates do not remain constant, significantly reduces accuracy in estimates of the normal rate of extinctions." > > >> It's no great mystery why some animals become extinct today, it's >> because 7 billion large mammals of the exact same species have spread from >> the pole to the equator, and that has never happened before. It would have >> been amazing if a event like that didn't cause a few animals to join the >> 99.9% that have already gone extinct in the last 3 billion years. >> > > It is not a few animals John--despite what you choose to believe - we > humans have triggered and are the cause of what is the beginning stages of > a great extinction event. > I don't think so but even if you're right do you have a solution that doesn't involve the extinction or at least a major culling of my very favorite animal? If so let's hear it. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
