Fast Fish Evolved Similar Design Separately

Science - Reuters ^ | 2004-05-05 | Patricia Reaney

[Junior]

LONDON (Reuters) - Great white sharks and tuna have a similar build for speed despite evolving separately for millions of years, scientists said Wednesday.

"Nature does it best in terms of design," said Jeanine Donley of the Scripps Institution of Oceanography in California. "It is amazing that they have developed to be so similar."

Lamnid sharks, which include mako and great whites, have been separated on the evolutionary tree from bony fishes, such as tuna, for over 400 million years. But the muscles and tendons that enable them to swim so fast are remarkably similar.

"Tunas and lamnid sharks have a body form that represents an extreme in biomechanical design for high-performance swimming," Donley said.

Lamnid sharks, which inhabit tropical to cold temperate waters in almost all seas, and tuna diverged from their ancestors in the design of their swimming features millions of years ago.

Their specialized features distinguish them from nearly all other fish and make them more like each other than their closest relatives.

The team, who reported their results in the science journal Nature, used video footage of sharks swimming in a tunnel and a device that measures muscle length during movement.

They believe it was evolutionary selection that allowed them to swim at high speed with a minimum of movement.

"There are body shapes...the roundness, the degree of tapering, even the tail shape, that you can calculate what would be approximately the most efficient for steady, straight swimming or burst swimming," Donley said.

"These two types of fish have this particular type of body shape which is ideal for hydromechanical efficiency."

Commenting on the research, Adam Summers of the University of California, Irvine, said scientists have been speculating on the similarities between tuna and mako sharks for decades.

"Understanding the mechanisms behind their locomotion could lead to high-speed autonomous underwater vehicles," he added.

[Southack]

"Mutations cause divergence. Selection may cause convergence."

No, "selection" causes nothing. At most, it can weed out something that already exists.

[Southack]

"I don't know. Based on the record, I'd bet that this one is also true."

Bets are mere expressions of faith/hope. My question was whether the scientific record of the genomes agreed with that faith.

This is non-trivial. What we have here is a potential opportunity to examine the falsifiability of Evolutionary Theory.

One such "falsifiability" would be direct evidence of specific DNA code completely skipping generations/species.

[Doctor Stochastic]

Selection acts like a filter. If you pass two populations through the same filter, the resulting groups will generally be closer together than the input populations. Two populations (just using numbers for the example) ranging over (1-10) and (5-50) respectively may be selected to be in the [2-20] range so that th results become (2-10) and (5-20) which are closer than the originals.

[Dimensio]

What we have here is a potential opportunity to examine the falsifiability of Evolutionary Theory.

One such "falsifiability" would be direct evidence of specific DNA code completely skipping generations/species.

You're absolutley right. IF such a thing is found, it presents a serious -- and quite possibly fatal -- problem for the theory of evolution. At the very least, some very fundamental aspects of the theory would have to be changed.

I don't suppose that you could provide a similar criteria of falsifiability for Intelligent Design "Theory"?

[PatrickHenry]

I don't suppose that you could provide a similar criteria of falsifiability for Intelligent Design "Theory"?

You still don't understand. The fact that ID theory can't be disproved is powerful evidence in its favor. The designer is of such awesome intelligence that his work is irrefutable.
</ID-creationism mode>

[Southack]

"Selection acts like a filter."

That's correct. But note that filters don't "cause" new properties...filters only reduce the number of properties that once existed.

[Southack]

"I don't suppose that you could provide a similar criteria of falsifiability for Intelligent Design "Theory"?

Intelligent Design is falsified in each realm where we see unaided processes create a new environment. To wit: an underwater volcano creating a new island is such an unaided process that shows clearly that the resulting island was created without Intelligent Design.

Is that what you were looking for, or did you simply want to make some point that would throw this discussion away from a scientific evaluation of the new discovery mentioned in this thread's title article regarding the potential re-use of genetic code?

[Southack]

One such "falsifiability" would be direct evidence of specific DNA code completely skipping generations/species.

"You're absolutley right. IF such a thing is found, it presents a serious -- and quite possibly fatal -- problem for the theory of evolution. At the very least, some very fundamental aspects of the theory would have to be changed." - Dimensio

Don't hedge your bets. Either state that this is a valid way to scientifically falsify Evolution (should the DNA prove to have skipped generations/species), or else show that this is *not* a valid way to falsify Darwinism.

Because hedging that bet isn't scientific.

[Dimensio]

Don't hedge your bets. Either state that this is a valid way to scientifically falsify Evolution (should the DNA prove to have skipped generations/species), or else show that this is *not* a valid way to falsify Darwinism.

I'm not hedging my bets. You don't seem to understand the nature of "falsification". Falsifying a theory does not necessarily mean completely tossing it out and starting over from scratch. If a theory is falsified, it's possible that the theory only needs revision. The previous iteration of the theory was proven "false" through the new evidence, but it is conceivable that a revised version of the same theory would account for all available evidence, old and new.

It is possible that a falsified theory is completely thrown out, but that is not always the case. Newton's theories of gravity and motion have been falsified, but they're still useful because they are only "false" in that they do not apply universally.

DNA skipping as you suggested would falsify evolution as we know it. Whether it would require completely disposing of the theory of evolution or if it would simply require that evolution be retooled (and it would have to be greatly retooled, IMO) to account for the new evidence is a matter of debate. Of course, the issue is moot until such "falsifying" evidence comes about.

[Doctor Stochastic]

Example of two disparate entities producing similar phenotypes. The model is two population masses that reproduce by doubling and move half to the left and half to the right (a random drift process). So starting with 1 unit, a single population goes to 101 thence to 10201 etc (Pascal-Khayyam-Hsien triangle.) The two entities do not interact but their totals are entered into the table. The vertical axis represents time and the horizontal axis represents pheonotypes.

After a few generations, a bell-like curve arises. The selection against high and low values has caused a confluence of the resulting pheonotypes.


000, 000, 001, 000, 000, 000, 000, 000, 000, 000, 001, 000, 001
000, 001, 000, 001, 000, 000, 000, 000, 000, 001, 000, 001, 000
001, 000, 002, 000, 001, 000, 000, 000, 001, 000, 002, 000, 001
000, 003, 000, 003, 000, 001, 000, 001, 000, 003, 000, 003, 000
003, 000, 006, 000, 004, 000, 002, 000, 004, 000, 006, 000, 003
000, 009, 000, 010, 000, 006, 000, 006, 000, 010, 000, 009, 000
009, 000, 019, 000, 016, 000, 012, 000, 016, 000, 019, 000, 009
000, 028, 000, 035, 000, 028, 000, 028, 000, 035, 000, 028, 000
028, 000, 063, 000, 063, 000, 056, 000, 063, 000, 063, 000, 028
000, 091, 000, 126, 000, 119, 000, 119, 000, 126, 000, 091, 000
091, 000, 217, 000, 245, 000, 238, 000, 245, 000, 217, 000, 091
000, 308, 000, 462, 000, 483, 000, 483, 000, 462, 000, 308, 000
308, 000, 770, 000, 945, 000, 966, 000, 945, 000, 770, 000, 308

[Doctor Stochastic]

They cause the distribution of the populations to change. That's all evolution is.

[PatrickHenry]

Don't hedge your bets. Either state that this is a valid way to scientifically falsify Evolution (should the DNA prove to have skipped generations/species), or else show that this is *not* a valid way to falsify Darwinism.

The "hedging" seems entirely reasonable. If it were established that there is "direct evidence of specific DNA code completely skipping generations/species," such evidence might indicate (I'm speculating here) that there is an as-yet undiscovered method of transfering genetic material. Anomalies are very useful to scientists. They could be so insurmountable that the theory fails, or they could (as with Mercury's orbit) indicate that the theory still needs refinement. That's how science works.

[Southack]

"They cause the distribution of the populations to change. That's all evolution is."

No, Evolutionary Theory is the proposed process of first mutating and then later selection/filtering.

The mutation part is important to this particular FReeRepublic thread because it *matters* if that mutation was natural/random/unaided *or* created by design...and this particular article for this particular thread is somewhat suggesting that in sharks and tuna there may be a way to scientifically *test* to see if which (natural or designed) is the case here.

Is there identical DNA in both the shark and tuna genomes that has skipped what would be in Evolutionary terms the intermediate species bewtween the two?

So contrary to your claim that Evolution is only about the filtering process, what really matters to modern science is the unmentioned (by you) mutation part of the proposed process.

[Southack]

"The "hedging" seems entirely reasonable. If it were established that there is "direct evidence of specific DNA code completely skipping generations/species," such evidence might indicate (I'm speculating here) that there is an as-yet undiscovered method of transfering genetic material."

The hedging is unscientific because it makes it appear as though you would still support Evolution even if the evidence went against it.

If DNA code skipping doesn't falsify Evolution, then what do you propose would?

Or are you saying that Evolutionary Theory isn't advanced enough scientifically to be considered falsifiable yet?

[Doctor Stochastic]

Evolution is a change in allele frequencies. Whether it occurs by selection or mutation doesn't change that part. Both are necessary to explain current observations.

[Dimensio]

If DNA code skipping doesn't falsify Evolution, then what do you propose would?

As has already been stated, it would falsify evolution, at least evolution as it stands now. The result would be either a) throwing out the theory of evolution entirely, or b) revising the theory of evolution in such a way that it accounts for all of the available evidence, including the new evidence which falsified the previous iteration.

That is how science works. That is how falsification works.

[Doctor Stochastic]

... *matters* if that mutation was natural/random/unaided *or* created...

In what way? What evidence is there that something other than sharks and tunas modified their respective genotype? Be specific.

[Southack]

"In what way? What evidence is there that something other than sharks and tunas modified their respective genotype? Be specific."

Math.

It's mathematically preposterous for two separate, unrelated processes to coincidentally create identical genetic programming subroutines of any length greater than 64 base-pairs of instructions, naturally (i.e. without aid).

[Doctor Stochastic]

...mathematically preposterous ...

Not a technical term.

...identical genetic programming subroutines...

Why do you make this claim? It's not in the original paper. If you wish to argue with yourself, feel free to do so.

[Agamemnon]

Sorry 'bout that. Make that 'near infinite abundance'. But the point is the same. Time created everything including all the Gods in the universe.

And now I'll challenge you to prove both of your statements. Start off with a cogent definition of the word "time" then follow that with an equally cogentently enunciated proof that time creates anything.

The last proof you must come up with of course is that time creates all the "Gods in the universe."

While you're doing that readers of this thread may speculate as to who (some bong-puffing evolutionism mystic, or just VadeRetro perhaps?) and what (Heaven's Gate Cult, Mother Wheel #19 a la Louie Farakkhan, some mental abortion clinic, maybe?) informs your certifiably SoCal powers of thought regarding concepts of time, rights of animals, lack of inherent right to life of the human unborn, and what is likely to be your scientifically unrecognizeable definition of life itself.