After my bike buddy and I noted the striking similarity between our praying bike rack supervisor and the big bug from Men in Black, I was happy to find this post from Science Blog. It has long been theorized that the age of the giant bugs in our fossil record correlated quite nicely with the sediment record for oxygen concentration in our atmosphere. The more oxygen there is, the bigger the bug can get. After an ecological upheaval, the oxygen levels went down, and now we have regular sized land based arthropods. So can we really test that oxygen levels were the basis for big bugs? Using x-ray techniques to examine the tracheal passages of several species, we see pretty good evidence that oxygen is the key. Huge beetles have more airways in their bodies than smaller insects, especially in their legs. Using calculations to see how big a predicted beetle could get, testing whether airways were more important if they were connected to the head, or if the limbs were better, the team at Argonne National Laboratory found their predictions for maximum beetle size matched fairly well with the largest known species. So, now we know, the big bug wearing the Edgar suit has a lot of tracheal tubes in his legs, and probably evolved on a high oxygen atmosphere planet. I'd still say my prayers if I ran into it though.
Of course a bug that size could not lift itself off the ground. The scaling effect would come into play regardless of oxygen supply. The exoskeletal design is ineffective for larger sizes. That is why nothing larger uses it.
ReplyDeleteA man the size of an ant could rip the ant apart if he could catch it, while an ant the size of a man could probably not lift a limb, much less stand.
Insects, reptiles, mammals, birds, and dinosaurs all produced flying variants but none exceed about 40 lbs and those close to the limit can barely take off.
I know this is old hat to you, I couldn't help running on. Sorry, Joe!
(I like mantises (mantisi?), I used to feed them in my shop. )
Heya Mac!
ReplyDeleteGravity does play a big role in the scaling of exoskeletons, which is why the bouyant force of water counteracting that gravitational force allows for huge crabs which we would never see on a beach. Of course, the size of that big bug in MiB was probably the least of the scientific discrepancies...
The movie was fun, though!
ReplyDeleteGee, you mean you can't have a molecule size star and still have enough gravity to support fusion? Tarnation!!!
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