16 June 2006

Webbed foot-note

This little footnote raises an often-asked, often-answered (in many differing ways) question:

the Cretaceous-Paleogene boundary, assumed 65 million years ago when some catastrophic event killed off all the dinosaurs (but apparently not the sparrows and ducks)

OK, so in my eyes the question is: what difference between sparrows and stegosauri won the sparrows a place in modern history, but the “roof-lizard” not?


Major said...

I don't know if there is a "canonical" answer to the question but given enormous differences between the species under discussion it would be more surprising if their fate was the same than for it to be different.

For just one, consider body weight:

Weight of sparrow: 20-30g
Weight of Stegosaurus: 3000-5000Kg

That is over five orders of magnitude difference in body weight with a corresponding difference in the amount of food one has to find.

As an aside: what is the young earth creationist explaination for the disapearance of stegosauri and their many dinosaur cousins (but not sparrows) given a much shorter time frame for it to happen in?

Leon Brooks said...

Major, sorry about the slack response to your comment, I didn't notice this one response in amongst the many others in this blog which I was notified about at the time.

I'll see if I can find an answer for you, but I'm guessing at this point that the... um... canonical one will hinge on the stegs not being so good at swimming during a really big flood & the spoggies being significantly better at rebuilding their population (breeding young and rapidly) after a year or so of hanging around on a big wooden boat with a handful of people and lots of other animals.

I'll post again if I see any real answer which is noticeably different to that. Every so often, a genuine jaw-dropper point pops up; not frequently, but they're well worth cruising for.

Major said...

So, in summary, the evolutionists and creationists agree that the answer is "differential survivability under stress" and differ only on the time-frame.

Is there any creationist expaination for the absense of stegosauri in cave paintings BTW?

"No Thag, don't draw that stupid stegosaurus, the bison is much more interesting"

Leon Brooks said...

Major: not sure that xxxosauri are absent from cave painting collections. I will check for references.

WRT survivability, I read the differences as relating more to the particular circumstances surrounding the species so compared.

Leon Brooks said...

Haven't checked the cave-paintings yet, but one firm reason for spoggies surviving better would be that their food would be much easier for them to find, speaking even in relative terms. OTOH, spoggies would also be much more hunted, so less survivable.

Leon Brooks said...

NatGeo seem to expect a more or less singular event (the Permian extinction) to have wiped out almost all life-forms (well over 90% of most) almost regardless of species, pretty much in one go.

A sparrow wouldn't have the endurance to survive such an event well, since however it happened (several theories are raised, all with similar outcomes) it would eliminate Mr Spoggy's food at least as thoroughly as Mr Stego's.