Saturday, May 19, 2012

CSI Cretaceous Part 1

Many posts ago I blogged about the present day genetic evidence which conclusively indicates that modern day birds are in fact descended from some of the very few dinosaurs that managed to survive the mass(?) extinction event(s?) that occurred at the end of the Cretaceous. Wanting to know more I picked up Robert T. Bakker's The Dinosaur Heresies which has turned out to be one of the better reads I have had so far this year.

Prior to writing this book Bakker along with a few other paleontologists had been challenging what had by mid-20th century become the orthodox position on dinosaurs. A view that represented dinosaurs as cold blooded, scaly, slow moving, and dim witted, i.e., reptiles par excellence. The thrust of Bakker's work was to show how this consensus was mostly wrong-headed, principally by arguing for the warm blooded nature of most dinosaurs. The Dinosaur Heresies then was meant to serve both as platform for getting these ideas out to the general public and as a place where Bakker could cumulatively present the evidence he had accrued through years of research. I'm no paleontologist of course but in my opinion Bakker succeeded on both counts.

But it doesn't really matter whether I found his arguments persuasive because since the book was first published in 1986 Bakker (and others) have been repeatedly vindicated so much so that what was then a revolutionary position has now become the general consensus among today's paleontologists. These ideas would come to influence Steven Spielberg with Bakker coming to serve as one of Jurassic Park's scientific advisers. Thankfully so since we might have been left with a plodding Tyrannosaurus rex who procured most of his food from scavenging rather than through hunting. The result would have been a decidedly less exciting film. (Note: there are still a few paleontologists who maintain that the T-rex was a scavenger. However, this remains a marginal view. Go here for more.)

The book itself is simply too rich to attempt a proper review here. Plus, I'm not really qualified to do so. But in the next couple of posts I want to talk about one chapter in the book that I found particularly illuminating.

One of the more fascinating mysteries when it comes to the dinosaurs has to do with their extinction. (Well, this is a bit of a misnomer since dinosaurs technically still exist as modern day crocs and birds.) Species of course come and go all the time, but what makes the extinction of the dinosaurs special according to Bakker is that "no new wave of species appeared to replace those that had died out." (436) And as Bakker notes the solutions given to this mystery have been many. Perhaps it's best to quote him at length here:

" is suggested that dinosaurs died out 'because the weather got too hot'; 'because the weather got too cold'; 'because the weather got too dry'; 'because the weather got too wet'; 'because the weather became too hot in the summer and too cold in the winter'; 'because the land became too hilly'; 'because new kinds of plants evolved which spread deadly diseases'; 'because new kinds of mammals evolved which competed for food'; 'because new kinds of mammals ate the dinosaur eggs'; 'because a giant meteor smashed into the earth'; 'because a supernova exploded near the earth'; 'because cosmic rays bombarded the earth'; or, 'because massive volcanoes exploded all around the earth.'" (425)

The view that came to be accepted in Bakker’s time and that is generally still held today (with some modification) is that a heavenly body of some kind, most likely an asteroid, impacted the earth some 65 million years ago wiping out most of the dinosaurs in one fell swoop. The primary evidence for this position has to do with a thin layer of iridium that features prominently in the geological record around the time of the end of the Cretaceous. This is significant because iridium is a noble metal that is “extremely rare on the earth’s surface, but much more abundant in celestial bodies such as meteors, asteroids, and dead stars.” (432) The idea then is that this iridium layer found in the geological record can best be explained by theorizing the impact on earth of a large extraterrestrial body some 65 million years ago that heaved up massive amounts of rich iridium clouds into the atmosphere which then eventually settled back onto the ground to form the iridium layer that geologists today have identified.

When this hypothesis is then viewed in light of the fossil record which indicates that most dinosaur species died out around the same time it’s hard not to see a correlation between the two. Additionally, mass extinction by an asteroid would explain why a few dinosaurs did manage to survive. For example, the ancestors of modern day crocodiles because of their cold blooded composition would have been able to hibernate so as to wait out the environmental changes such a collision would have caused. Similarly, small theropod dinosaurs and tiny mammals could have burrowed and waited out the changes as well only to later emerge and evolve into birds in the one case and our mammalian ancestors in the other. So then it is easy to see why this theory of dinosaur extinction has persuaded most and continues to be promulgated in various dinosaur media today.  

But there is a problem with this hypothesis that keeps a few like Bakker from fully adopting it. This, along with Bakker's peculiar solution, we will look at next time. 

Tuesday, May 8, 2012

Learning to Take Seriously Israeli Fears of a Nuclear Iran

 The pursuit by Iran for nuclear power has been a festering issue for the International Community since at least the 1990's because it is widely believed that Iran would use any acquired nuclear capability chiefly for the purpose of developing nuclear weapons. But because Iran was thought to be light years away from even the first steps towards this goal (e.g., successful uranium enrichment) the IC's attention towards this potential flashpoint waxed and waned over the years. However, important events occurred after the millennium which helped to renew the IC's concern over Iranian nuclear ambitions.

First, of course, was 9/11 and the subsequent lumping of Iran by the Bush administration into the "axis of evil" category. (For some in the Bush administration this labeling of Iran as "evil" appeared to be justified as the post-Iraq war insurgency began to flare up and it was soon discovered that Iran, if not outright directing much of the sectarian violence by providing weapons and such, was at least encouraging much of it.) The second major development was the "election" of Ahmadenijad as the Iranian president who before long began to make many in the West, and especially in Israel, uneasy with his vitriolic speeches that among other things repeatedly denied the Holocaust and called for Israel to be "wiped off the map." And lastly recent intelligence estimates, particularly after 2007, seemed to indicate that Iran was closer to nuclear capability than previously thought. All of these factors combined to renew the IC's effort to bring pressure on Iran to forgo its nuclear ambitions. Surprisingly, a number of sanctions have been passed including a European oil embargo set to go into effect in June. (Unfortunately, it is likely that many European countries will find ever ingenious and elaborate ways to circumvent the embargo as they did with the Iraqi "Food for Oil" program in the 1990's.)

Obviously, the major concern by the IC is that the Israeli's are getting ever closer to preemptively striking Iranian nuclear sites. That this is highly probable is undeniable since the Israeli's have thus twice before acted (Iraq, 1981; Syria, 2007). Rightly, then, the world is concerned about the repercussions that would surely follow from an Israeli airstrike on Iranian nuclear facilities.

Now for my own part, from the viewpoint of US strategic interests, permitting Iran nuclear weapon capability is probably not as problematic for the region as some suggest and would not directly affect the national security of this country. Therefore, I'm inclined to view the Iranian government as a "rational" actor on the international stage that wouldn't recklessly use its nuclear weapons. Of course this is not what many fear would happen if Iran had nuclear weapons. The more likely scenario is that Iran might smuggle nuclear weapons to one of their proxies such as Hezbollah or Hamas to use against Israel so that the IC could never officially link any use of nuclear weapons against Israel to Iran. Still, I think it is unlikely Iran would act in such a fashion.

But having said that I want to stress that it is important not to be glib about the security threat a nuclear Iran poses from the viewpoint of Israel. Israeli security calculations have to take this situation seriously because it has been in a position since 1948 of actual and virtual war which combined with the history of Jewish persecution that tragically culminated in the Holocaust has, quite understandably, developed into a national security consciousness with a strong existential flavor. Thus, asking the Israeli's to explain exactly how and why a nuclear Iran would be dangerous for the region is an irrelevant and meaningless question to put to them.

Also while many in the West have no problem shrugging off Ahmadenijad's speeches (specifically the ones that have called for "Israel to be wiped off the map") as mere rhetorical flourishes the Israeli's cannot afford to do this. That this is simply political grandstanding cannot (and should not) even factor into Israeli security calculations.

Usually, I'm cautious about using historical analogies since they are often misused, but if you remember Hitler gave a speech in 1938 which called for the "destruction of international Jewry". At that time, like Ahmadenijad's diatribes today, the speech was waved off as typical antisemitic blustering, exaggerated political sophistry. Then seven years later the world learned that Hitler had "succeeded" in destroying 1/3 of world Jewry.

So then the greater challenge isn't getting Iran to give up its pursuit of nuclear weapons but rather of getting the Israeli's to modulate their own security interests to coincide with those of the United States and the rest of the IC. But this will never happen. Rightly so Israel will act out of what it perceives is best for its own security, regardless of what the rest of the world believes it should do. As would the United States, as would any country for that matter. And therefore whether we disagree with the Israeli position or not concerning its fears of a nuclear Iran it is vitally important that we seek to understand that for Israel this is indeed an existential threat.

In short, no matter how vain or empty threats made towards the Israeli state by a country such as Iran might look to the IC, it is impossible for Israel NOT to take each and everyone of these seriously. Its own history demands such.

Thus, we need to be careful when discussing Israel's security concerns vis a vis Iran that we do not do so in a cavalier manner as, tragically, I've seen too many political commentators do.