Algae First To Recover After Asteroid Strike 86
pickens writes "The asteroid that impacted earth 65 million years ago killed off dinosaurs, but microalgae bounced back from the global extinction in about 100 years or less. Julio Sepúlveda, a geochemist at MIT, studied the molecular remains of microorganisms by extracting organic residues from rocks dated to the K-T extinction (in this research referred to as Cretaceous-Paleogene), and his results show that the ocean algae community greatly shrunk in size but only for about a century. 'We found that primary production in this part of the ocean recovered extremely rapidly after the impact,' says Julio Sepúlveda. Algae leave certain signatures of organic compounds and isotopes of carbon and nitrogen; bacteria leave different signatures. In the earliest layers after the asteroid impact, the researchers found much evidence for bacteria but little for algae, suggesting that right after the impact, algae production was greatly reduced. But the chemical signs of algae start to increase immediately above this layer. A full recovery of the ocean ecosystem probably took about a million years, but the quick rebound of photosynthesizing algae seems to confirm models that suggest the impact delivered a swift, abrupt blow to the Earth's environment."
heh (Score:3, Insightful)
How does one 'bounce back' from *extinction*?
Re:Good news for Microsoft (Score:5, Insightful)
Well, if the scum are the quickest to recover ....
Shit, I guess that means we can't count on an asteroid to take care of our politicians and lawyers.....
Re:Wow, fascinating. (Score:1, Insightful)
Re:My magical toilet (Score:1, Insightful)
Re:heh (Score:3, Insightful)
You make a fare point. Many species survived altogether. We didn't evolve from scratch again within 65 million years - some animals survived and in turn evolved into the species that took the place of the dinosaurs. Saying that these "bounced back within 100 years" strikes me as odd, as there were necessarily lots of species of plants and animals still alive and surviving from the day past the strike up through and past the 100 year mark.
Re:Old science (Score:3, Insightful)
It helps to focus on the observable facts (e.g. the distribution of dinosaur fossils in geological strata) in preference to speculations of individual scientists. The fact is: no fossils of non-avian dinosaurs have yet been conclusively dated above the KT impact boundary, but fossils of a number of non-avian dinosaur genera have been found very close to the KT event (making it extremely likely that they existed at the KT impact time). A few claims of post-KT non-avian dinosaurs have been made, but have not stood up to closer investigation.
See for example: http://gsa.confex.com/gsa/2003RM/finalprogram/abstract_47695.htm [confex.com]
Since the distribution of dinosaur fossils close to the KT event has received by far the most scientific attention the failure to find any surviving lineages after the event is striking.
I would be fascinated to know what actual evidence (as opposed to speculation) that your unnamed, unsourced microbiologist could possibly have of a disease striking all non-avian dinosaurids, given the limitations of the fossil record. Proposed alternate scenarios (generally lacking any evidence) are all over the map and are a dime a dozen. Looking at all conceivable possibilities is good science, but one needs to keep such speculation in perspective.
Working out all of the details about events unfolded around the time of the KT impact, and the recovery period after, is a project that will likely never be finished -- there are so many possible mechanisms, scenarios, and sub-scenarios and the evidence is (and always will be) restricted.
But to assert that "the dinosaurs being destroyed by the asteroid strike is almost mythology" is a fantastic distortion of the situation -- it is not noticing the Amazon rain forest because of all the trees.