[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Theory on ornithoptering and could Archie do it ?



I'll make this short and sweet. Since Archeopteryx and origins of flight aren't 
exactly my best studied subjects, I apologize in advance for any errors that I 
might make.

Okay so one of the big questions circulating through paleontology today is: How 
powered flight evolved. 

>From this question came the two basic theories of either ground up or trees 
>up. Both have been discussed in detail, so I'm sure we've all heard them.

The one theory I'm addressing today (or night depends on when you read this) is 
trees up, the more popular (for the moment). 

It seems to make sense that an animal gradually became a flyer as it jumped 
from tree to tree after insects and away from predators. The problem that 
arises from this of course is that most animals that do this today are gliders. 
In all respects gliding is a more eficient way to go from tree to tree. Just 
jump off and let the wind carry you to the next tree, don't even have to bother 
with energy sapping flapping. 

So that's fine and good. So how does one go from a glider to a powered flyer 
(ornithopterer?) 

Well from the information that I've gleamed off of sugar gliders and draco 
lizards, it seems that they glide from tree to tree for two main reasons:

1: It's the fastest way to get from point A to point B

2: It is a highly effective way of avoiding predators.

Both of these animals don't seem to capture food by gliding. In fact when one 
thinks of it, gliding isn't the best way to catch insects.

Think about it. A glider needs the momentum of their falling bodies to keep 
them going. Some like dracos are efficient at turning and keeping airborne for 
a long distance. But the insects that a glider would chase are powered flyers. 
Many insect flyers like bees and flies are not only very fast, but very agile 
too. 

So if we go back to Archie's time and pick an insect for it to chase (say a 
dragonfly) then let it chase it. What's going to happen.

Well if we believe the theory that Archie can only glide (I don't know if this 
was disproven or not) than we can imagine this little bird dropping from a 
branch and zooming down towards the dragonfly. The next thing we see is the 
dragon fly dart to one side as Archie goes by and misses.

That's the problem with chasing an ornithoptering insect. They have that nasty 
habit of zig zagging and darting in all kinds of weird directions. As a glider 
your running on borrowed time, these insects on the other hand (by 
ornithoptering) are making their own time. Doesn't it make sense to find a 
better way to chase them.

So that's one scenario (I might have over anthropomorphized a little)

Now here's a more intriguing one.

What if that Archaeopteryx that flew down from the tree and just missed that 
darting dragonfly, turned around and, with some short flaps to regain speed, 
went after it again.

I'm not suggesting a complete ornithopterer here, but just the occasional flap 
to help it keep up the chase. This occasional flap would no doubt show up as a 
benefit and the evolution of powered flight commences.

Now from what I've heard Archie is missing that enlarged sternum for it's wing 
muscles, so it is said that it can't fly.

Still I've also heard that their were large muscle attachments to the furcula 
(I believe that's where they were) that would have allowed Archie to flap.

Even a weak flap, could be an advantage. Especially when trying to keep up with 
a fast moving insect.

I don't know if this solution was ever fully addressed (both here and in 
science papers) but it seems like a plausible one to me.

While gliding is fine for escape and all. Catching food with it is harder.

I also of course can only hypothesize how it could have happened in such a 
scenario. Maybe ornithoptering insects haden't invented the zig zagging 
movement at the time. Maybe stress from early gliders forced such an adaptation 
to evolve. This in turn might have forced ornithoptering flight in vertebrates 
also to evolve. Which would have made insects even more erratic and so on.

Just some thoughts, even if they might be rehashed.

Archosaur J

Now as for how powered flight in insects evolved. That's anyone's guess.


____________________________________________________________________
Get free e-mail and a permanent address at http://www.netaddress.com/?N=1