New Theory Of The Evolution Of Bird Flight Linked To Parental Care

Science Daily ^ | 1/30/2002 | UC Davis Press Release

[longshadow]

BTW my source disagrees with the Mars value of 23.98°, it has the value as 25.19°---Mars fact sheet

Upon further inspection, it appears your source provides "Obliquity to Orbit"; my source simple refers to the parameter as "Inclination of Axis." If the Inclination of Axis is measured with respect to the ecliptic instead of the Martian orbital plane, the two values should vary by the amount equal to the Inclination of the Martian orbit to the ecliptic. This value is listed as 1.85° and change, which when subtracted from your source's figure of 25.19°, yeilds a figure very close to Norton's value for "Inclination of the Axis."

In the alternative, I suppose Saturn could have swooped in on Mars while we weren't watching during the past 30 years and side-swiped it, causing the axis to change it's inclination. That would fit right in with the rest of medved's planetary weirdness.

[medved]

Hmm, there are a bunch of creationists on FR. I think the latest one was exnilhio(sp?). He was posting Intelligent Design articles that had been discussed before. There is also Gore3000, and medved. I get a kick out of medved, because his pet theory is that the earth used to revolve around Saturn.

The fact of the matter is that, no matter how stupid the Saturn thesis may sound to you, it doesn't begin to compare to evolutionism. In fact, I could even believe that we were orbitting Saturn NOW and even that would be positively brilliant compared to evolution. Nothing in the Saturn theory involves an infinite sequence of zero-probability events and nobody is demanding that the Saturn theory be taught at a fact in public schools at public expense. You have to keep these kinds of things in perspective.

[Vercingetorix]

"Nothing in the Saturn theory involves an infinite sequence of zero-probability events and nobody is demanding that the Saturn theory be taught at a fact in public schools at public expense." -- medved

A single zero probability event suffices for the honest man. The claim that there are an infinite number is a didactic device with one purpose -- to deceive. This permits the proselytizer to retort that even though every single zero probability event he is capable of itemizing is shown instead to have a probability of one there are still an infinite (not itemized) number left to substantiate his false claim.

A famous biologist (I forget who) once replied "Statistics are for losers" to a colleague who requested numerical data supporting the biologist's thesis. By this he meant that understanding how something actually works cannot be achieved by simply measuring a few parameters of the system and calculating averages and variances. Once the mechanism is described and the processes determined it is possible to predict the behavior or response of the system without resorting to statistics.

It is also well known that statistics can be manufactured to suit any purpose (e.g., "How to Lie with Statistics"). Nowhere is this fault more apparent than in the purposely deceitful use of statistics to "prove" that known events (i.e., evolution) did not happen.

[medved]

"Nothing in the Saturn theory involves an infinite sequence of zero-probability events and nobody is demanding that the Saturn theory be taught at a fact in public schools at public expense." -- medved

A single zero probability event suffices for the honest man.

I take it you do not believe in evolution. Or are you claiming to be dishonest?

[Vercingetorix]

"I take it you do not believe in evolution. Or are you claiming to be dishonest?" -- medved

Belief does not enter into it. Understanding evolution depends only on knowledge of the physical world. The existence of the process of evolution is an irrefutable fact. Life on this planet is old and has changed continuously since its inception.

You seem not to recognize these simple facts yet you espouse preposterous conjectures with no basis in reality in order to create the appearance of statistically impossible events that preclude the natural progression of life over time. Here is a simple test of your method. Try it going backward through time. Life begets life in a continuum. Life today is clearly different than life even in the recent past. Because you will be dealing with known events (probability one)at every stage you will be forced to recognize (if you are honest) the absurdity of your zero probability argument.

[medved]

Belief does not enter into it. Understanding evolution depends only on knowledge of the physical world. The existence of the process of evolution is an irrefutable fact. Life on this planet is old and has changed continuously since its inception.

Microevolution is a fact. Anything else, including the so-called theory of evolution, in all its guises, is an ideological doctrine and a belief system, like communism or naziism. Try reading through my large post above for comprehension rather than simply for making your knees jerk. The arguments involving probability are sufficiently real. Evolutionism and mathematics are incomparible. You've got world-class mathematicians like Fred Hoyle and Bob Bass claiming macroevolution is impossible and you had the Wistar symposia at which a collection of the world's best mathematicians told the evos they were FUBAR. You're beating a dead horse.

[Vercingetorix]

"Try reading through my large post above for comprehension rather than simply for making your knees jerk." -- medved

You must have posted that thing about 200 times by now. I practically have it memorized. It contains not a single valid argument and this has been pointed out to you well more than 200 times.

Crusading pseudomathematicians can write as many equations as they want. Examine their assumptions and there are always mistakes. No exceptions. Hypothesizing fictitious conditions to produce a predetermined outcome is a piece of cake for a motivated math hobbyist. Mathematicians or biologists modelling real systems however have no problem producing equations with real predictive power. Try reading Stephen Hubbell if you finally want to dispel your persistent illusion that math is incompatible with real biology.

[Gladwin]

What do you think about the above theory of birds? Does it sound reasonable?

[Vercingetorix]

Carey's bird evolution hypothesis makes sense. Parental care is an avian fitness characteristic -- they all display it to a remarkable degree and in every habitat. It would be remarkable if the evolution of flight was not dependent in large measure on this defining behavior. The particulars, of course, are largely a matter of speculation but his theory suggests a worthy line of investigation.

[Cleburne]

The feathers on Archaeopteryx fossils appear to be much more advanced than the creature's other birdlike traits, which is consistent with the notion that feathers evolved very early to shield the nest-sitting adults from the elements;

Oh, I see. That's why the pterodactyl went extinct? It couldn't shield its young as well? How precisely would feather outweight skin in shielding against the elements? And a bird would evolve relatively complex feathers merely for the purpose of shielding young against the elements? Did it develop feathers before or after it developed the claws, before or after it started roosting in trees? Can any of these questions be answered?

I don't personaly see that many of these questions can be authoratively proven- so why spend tax money on it? Yes, we should pursue knowledge, but can we expect to discover why birds evolved wings?

[Gladwin]

I think things with hair or feathers stay warmer than without. That is why people wear clothes in the winter! lol

[Cleburne]

Don't some scientists theorize that pterodactyls had fur, and were possibly warm blooded? That, and wouldn't the earliest birds have lived in a very mild, tropical climate?

[Gladwin]

Hmm, don't know. Maybe someone else does?

[Cleburne]

A quick Google search reveals mixed opinions, but mostly in favor of warm-blooded, fur (or fur-like) bearing. Of course, it seems that paleontologists sway back and forth in theory like a tree in a Gulf storm.

[GOPJ]

What survival function could a partially formed wing provide a bird? It's not logical to assume a useless appendage would keep developing over hundreds of years. A part wing is no wing.

[Gladwin]

I think the argument above is that the "wings" were originally prehensile and covered with feathers for warming the bird eggs. The gliding ability became more and more important and turned into true flight.

[DouglasKC]

He suggests that modern birds' very early ancestors were reptiles that established and guarded their nests on the ground, much like crocodiles. Over time, these creatures developed hard-shelled rather than leathery eggs and the ability to modulate their own body temperature in order to provide a more constant environment for their developing young. Scales evolved into feathers, better camouflaging and insulating the parents.

This is kind of stupid. If scales are going to "evolve" into feathers in order for better camoflage and insulation, why didn't scales just "evolve" into fur and/or a fat creature with fur? I thought the reason why birds have feathers is that they enable flight while still providing warmth.

And if this theory is true, then why didn't everything develop feathers? For example, if warmth and camoflage is the criteria, then fat and fur seem to much more practical and would hold an advantage over feathers for the simple reason that fur is easier to maintain than feathers. The loss of one feather is more of a loss than the loss of one piece of hair.

[Gladwin]

I'm not sure that species have a choice about whether they develop fur or feathers. There is an initial random mutation in one direction or the other and once each path is set, it is "hard" to change tracks to the other. The proto-bird would not only have to mutate to get rid of its feathers, but would also have to mutate to get hair. This implies a naked bird running around that is freezing its butt off, and isn't able to fly either.

[DouglasKC]

I'm not sure that species have a choice about whether they develop fur or feathers. There is an initial random mutation in one direction or the other and once each path is set, it is "hard" to change tracks to the other. The proto-bird would not only have to mutate to get rid of its feathers, but would also have to mutate to get hair. This implies a naked bird running around that is freezing its butt off, and isn't able to fly either.

The problem with the theory is that the little proto bird who just needed to keep warm and camoflaged had not a clue that one day it would also have to fly. If feathers are going to randomly appear one day (no mean trick in itself considering their complexity) for the express purpose of warmth and camoflage, then the obvious evolutionary advantage would have been to evolve as a penguin form, useless for flight, but great for warmth. Then, we're asked to believe that a different function was needed for the feathers, so the warmth feathers have to devolve and re-evolve into feathers good for another use. Not bloody likely.

[Gladwin]

I don't know enough about bird feathers to criticize your point. Or, what the possible path from scales to feathers would be. Maybe someone else does.