Posted on 03/01/2002 8:55:03 AM PST by Oxylus
Ancestors of the flightless figurehead of extinction island-hopped.
The flightless dodo's ungainly shape hid an island-hopping past, say researchers. DNA from the extinct bird has revealed its place in the pigeon family tree, and suggests how it came to end up on its home, and graveyard, the island of Mauritius.
The dodo's strange appearance led to centuries of wrangling over its ancestry. "It's the figurehead of extinction, yet little is known about its evolution," says zoologist Alan Cooper of the University of Oxford.
Cooper and his colleagues extracted DNA from museum specimens, including the one in Oxford that was the inspiration for the dodo in Alice's Adventures in Wonderland.
Poignantly, the dodo's closest relative is also extinct, the team found. The solitaire pigeon (Pezophaps solitaria ), which was also large and flightless, lived on Rodrigues Island, 550 kilometres northeast of Mauritius. It died out in about 1765, a century after the dodo (Raphus cucullatus).
These birds are descended from Asian pigeons. The common ancestor of both species began its passage across the Indian Ocean about 43 million years ago.
The proto-dodo probably used the Mascarene islands as stepping-stones, the researchers suggest. This chain of volcanic islands also began to appear about 43 million years ago, stretching south from the Asian mainland. Many of the Mascarenes have now sunk back beneath the waves.
Mauritius and Rodrigues are youthful outposts of the group: Mauritius is about 7 million years old, Rodrigues a mere 1.5 million. Cooper speculates that the solitaire and dodo reached their new homes by air, later evolving flightlessness independently. "Rodrigues is far off over some deep ocean," he says. "It'd be a lot easier to fly there." References
* Shapiro, B. Flight of the dodo. Science, 295, 1683, (2002).
© Nature News Service / Macmillan Magazines Ltd 2002
Been a long, long time since penguins could fly.....
Do the evolutionaries think 1.5 million years enough time to go from a true loooooong-range bird (like the seagull obviously) to a near fish/porpoise that is the modern sea-swimming, fat-unsulated, feather-smoothed, stream-lined penguin (or the fat dumpy land-based dodo bird)?
See - EVERYTHING has to change from species one to species two (according to evolutionary theory), and in the middle, there's little advantage to the "half-bird/half-fish" freak to continue to live through enough generations - each getting progressively "worse" until finally the last "penguin design" works efficiently.
Of course, then they tell us that the last "design" (of the final penguin bird-shape or dodo bird shape) doesn't continue to change.
Hmmmmn.
Now, what's makes more sense (logically) is that there was a Designer of the penguin ... and He either hiccupped (or sneezed) at the wrong point in time and accidently made a few dodo birds.
And probably a few liberals too.
I'm afraid that you need to learn a good deal more about evolution and mutation.
It wasn't easy. I'm beginning to think blam has staff working for him.
Dam*! That proto-dodo must've been a heckuva BIG BIRD!!!
Not sure if that's a nifty insult or a nifty new screen name. I'll have to think about it over the weekend.
ROTFLOL! He surely does seem to have a patent on odd (but interesting) news stories.
Any change will either kill the mutated creature outright, or reduce the chances of it successfully mating (it is sterile or dies young, or can't feed itself), or prevent it outright from mating (the mutation creates less desireable traits to the possible mates of the opposite sex - i.e.; a mutation that attracts males to a male and so reduces the potential for children is NOT a survival trait, according to the liberals at least.)
So, almost ALL mutations are "bad" and kill creatures that would have survived if they had been "normal." (Therefore, almost all creatures are "normal" and the rest either "unfit, but not too bad" or "unusual, but not too good to have been changed very much.")
A gene that creates a 8000 lb horse is NOT good - because that horse, when chased as a colt gets rapidly killed by faster wolves and mountain lions who can run it down. EVEN if such a gene MIGHT attract more mates later on, and and MIGHT be better at self-defense later .....
Nature can't design things, according to evolution; only random mutations happen.
You are assuming these random mutations happen often enough, and in the "right direction" often enough at the right locations so BOTH sides of the future family are able to tolerate future mutations; are able to mate themselves; and those changes are successfully passed down.
Once changes "far enough" evolution then assumes that no further changes are successful .... so the original mutation "stops" becoming a mutation and becomes the normal.
Then the original gene stops changing - a "no-further-mutation-in-this-gene" clause is written ? .... and something mutates somewhere else in the creature's body to change (successfully!) something other body part ... all this required to achieve a final transmutation from one species to another.
Yes, multiple changes could happen at once ... but doesn't even further reduce the chances of a successful (mating) .... if one leg and foot developes into a frog-like webbed foot ... does that help or hurt me as I try to hunt on the shore?
I am, afterall, not able to swim fast enough to hunt fish successfully ... and can no longer climb trees to escape leopards and chimpazees by taking advantage of my improved fingers and newly opposed thumb.
So I (and my improved thumb!) die quickly, consumed by a leapard at age 6.
How many more billions of mutations does it take to create somebody who has a good thumb ... and no other problems?
What, then you're saying all those ducks (surely "'half-bird/half-fish' freaks" by your standard) are going to go extinct any day now?
The rare occasions when mutations are favorable usually result in a population with the new mutated gene; this occurs quite rarely however.
That's precisely my point. In order to evolve from a bird that has flight to one that doesn't the mutation has to be favorable. Apparently the population was transformed over some number of generations from flighted to flightless. Therefore, losing the ability to fly had to be a survival advantage.
That is the mechanism under Darwinism where transmutation of species occurs - a mutation gives an advantage and over time all the birds with this new advantage displace the ones without it, because they are more likely to survive and reproduce. If it's not an advantage, then the mutations cannot possible displace the others. It's called survival of the fittest.
Ducks were created ("have evolved accidently through millions of mutations" according to evolutionary theorists) with the same four appendages (that WE began with!) to paddle efficiently FLOATING ON water .... while SHEDDING water (by extra oil on the feathers) efficiently from the same feathers that allow them to FLY efficiently and WADDLE (sort of effectively) on land.
All by accident, of course.
Now, my question is:
WHAT is efficient about ANY of those "things" if they are NOT ALL present at the same time?
Why should all four MAJOR, life-threatening mutations occur to their appendages in such an order that "ducks" could survive BEFORE they could fly, float, paddle, and walk at the same time .....
In other words ... if (before their feet were webbed as they are now) their legs were weaker or less effective, then how did survive to "Become" the ducks we know now?
Without a Designer, that is.
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