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'Reverse Evolution' Discovered in Seattle Fish - Comments

davemei's Avatar Comment 1 by davemei

No...I'm pretty sure that god issued the boney plate armor to the sticklebacks, providing safety from the trout and other fish that used to feed on them

...though...it sucks for the trout....

Thu, 22 May 2008 05:53:00 UTC | #174131

movingshadow's Avatar Comment 2 by movingshadow

"There aren't many documented examples of reverse evolution in nature,"


No? Thousands of flightless birds aren't good enough for you? Maybe its that "Reverse evolution" is kind of dumb idea since it implies direction?

Thu, 22 May 2008 06:00:00 UTC | #174137

BaldySlaphead's Avatar Comment 3 by BaldySlaphead

And the frogamander in the same day - suck it, God.

"All in all it's just a-nother brick in the wall..."

Thu, 22 May 2008 06:01:00 UTC | #174139

bugaboo's Avatar Comment 4 by bugaboo

"Reverse Evolution"? I dont know what that means.I suppose they think the species present is less complex than its predecessor but so what. Its just Evolution

Thu, 22 May 2008 06:06:00 UTC | #174141

rod-the-farmer's Avatar Comment 6 by rod-the-farmer

And how will the fundies respond to this item, when one of their common statements is "No one has ever seen evolution happening." ?? Or how about the frogamander ? Swoosh - the sound of two more gaps closing (think of the doors on the starship Enterprise).

Thu, 22 May 2008 06:12:00 UTC | #174145

Bonzai's Avatar Comment 8 by Bonzai

"Reverse evolution" does happen sometimes.How else do you explain Wooter aka "clearmind"?

Thu, 22 May 2008 06:15:00 UTC | #174151

ChrisMcL's Avatar Comment 7 by ChrisMcL

If you want to see reverse evolution, just visit a church on any given Sunday. There you will likely find a neanderthal, like John Hagee, behind the pulpit.

Thu, 22 May 2008 06:15:00 UTC | #174149

rodviking's Avatar Comment 9 by rodviking

Terms like "reverse evolution" are misleading, as it implies that evolution has some kind of direction, or is some kind of ladder to be climbed up and down; wouldn't it would make more sense to say something like "reversed characteristic"?

A lot of creationists use this widespread idea of evolution meaning "improvement" to justify some of their misconceptions, so I think it's a good idea repeat over and over again that evolution simply means "change", it has no direction, purpose or intention.

Thu, 22 May 2008 06:20:00 UTC | #174153

epeeist's Avatar Comment 10 by epeeist

Comment #183483 by rod-the-farmer

Swoosh - the sound of two more gaps closing (think of the doors on the starship Enterprise).
And four more gaps opening...

Thu, 22 May 2008 06:21:00 UTC | #174154

Tezcatlipoca's Avatar Comment 11 by Tezcatlipoca

Even more than four new gaps if the postulated divide between the wormlike amphibians and the frogmanders is as early as is being presented.

Thu, 22 May 2008 06:24:00 UTC | #174159

Dax's Avatar Comment 12 by Dax

As someone who works in research, and will continue his academic career in science, I oppose the phrase "reverse evolution"... it's only reverse from the feebleminded perspective of the human mind: "oh, it had armor, then it didn't, now it does again. It must be 'reverse evolution'"
It's a stupid thing to say. Scientists might understand what they are conveying, but the public will just gobble this up with their ignorant ears that only feed on sound bites. It's just as stupid as non-theistic physicists using "god" as a metaphor!

Thu, 22 May 2008 06:31:00 UTC | #174163

Mike O'Risal's Avatar Comment 13 by Mike O'Risal

Rodviking,

There is already a term for this in evolutionary biology; it's called a reversal. This is when a character independently reverts to resemble a state found in an ancestor, sometimes a very distant one. It's a form of homoplasy, that notorious headache one gets when trying to reconstruct a phylogeny.

While not quite as common in morphology, reversals are almost par for the course in molecular biology, particular when one is examining sequences that aren't under strong selection. With only four bases to choose from, reversals in non-coding regions come up all the time where they're the result of multiple hits (changes between bases that occur again and again over the course of history).

Example: Ancestral organism sequence - ATGACTAGG
12 Generations Later - ATGAATACC
37 Generations Later - ATGACTAGG

If this (ridiculously short) sequence were used to infer phylogeny all by itself, we would likely make the incorrect inference that organism-37gen was more closely related to the ancestral organism �" and be wrong about it.

Luckily, there are numerous ways to remedy the problem.

It's not "reverse evolution," though. That's a rather silly phrase. Evolution either goes forward or not at all.

Thu, 22 May 2008 06:39:00 UTC | #174168

Bonzai's Avatar Comment 14 by Bonzai

bugaboo and other pedants,

In context "reverse evolution" here means that the fish retraced a few steps back along its evolutionary history, it makes perfect sense and it doesn't suggest any intrinsic or preferred direction to evolution. It is like saying you're going somewhere from home and while on your way see a road closure and have to backtrack towards the home direction, it is a reversal no matter which direction you were heading originally.

Thu, 22 May 2008 06:45:00 UTC | #174173

EvidenceOnly's Avatar Comment 15 by EvidenceOnly

Couldn't we consider the rising tide of IDiot and GodDidIt religious freaks as a form of reverse evolution back to the dark ages?

:)

Thu, 22 May 2008 06:50:00 UTC | #174176

Mike O'Risal's Avatar Comment 16 by Mike O'Risal

No, Bonzai, not really. The fish didn't retrace any steps. What it has evolved are new character states that mimic ancestral states. The states look alike, but the history of how that state arose in the "younger" species is different than that in the "older" one.

To use your analogy, it's more like there was a detour, so instead of going straight home you turned left, drove three miles, turned right, and arrived at a building that looked just like your old one and which happened to use the same key to open the front door.

Thu, 22 May 2008 06:50:00 UTC | #174177

bugaboo's Avatar Comment 17 by bugaboo

Comment #183511 by Bonzai

In science you have to be pedantic. I (and others)dont like the use of the term "Reverse Evolution". Its meaningless. Other terms /phrases crop up from time to time much to our chagrin eg "more highly evolved" Would we be being pedantic if we took issue with that?

Thu, 22 May 2008 06:55:00 UTC | #174180

Bonzai's Avatar Comment 18 by Bonzai

Mike,

If the house looks exactly like yours and you can open its door with your key it is probably your house.

You are absolutely right that the "retracing" doesn't have to, and likely won't go through the same path, so I should have said instead "revisit some earlier states in its evolutionary history,--or at least states that are sufficiently close to those"

In that sense it is a "reversal". To my knowledge there is no principle in biology that says that you cannot talk about a state without specifying how you get there. You can reach the same state (or the same cluster of states in some "phase space") through different paths How you get there would depend, among other things, where you were. So it is still your house even though you might have taken a different path home.]

EDIT The main point is that in context, I don't find anything in the phrase "reverse evolution" that may suggest inappropriately that there is an intrinsic direction to evolution.

Thu, 22 May 2008 07:00:00 UTC | #174184

Mike O'Risal's Avatar Comment 19 by Mike O'Risal

Bonzai,

The point is that it isn't the same house. You might well go inside and find that it looks entirely different.

For instance, in the example from the Nat Geo article, they're only looking at (or at least talking about) a very small number of characters. If they were to look at a broader selection, they would certainly find other difference. For instance, they might find changes in genes that code for the deposition of calcium that are different than the ones in earlier-evolving populations of the same fish. There may also be changes in other morphological characters; perhaps the swim bladder is a bit different. Maybe the tail fin has changed a little bit. When reconstructing the evolutionary history of a species, population, etc., it is very bad methodology to pick a single trait, or even too few traits. That's what induces sampling bias and screws up overall inference.

Homoplasy can be a major problem in phylogeny. You can certainly talk about a state without reference to how it arose, but you can't say anything about evolutionary relationships between populations without doing so.

Thu, 22 May 2008 07:07:00 UTC | #174189

Appleby's Avatar Comment 20 by Appleby

I was hoping for before-after pictures.

Thu, 22 May 2008 07:25:00 UTC | #174194

Mango's Avatar Comment 21 by Mango

We tend to think of genes as set in stone unless random mutations that are "successful" lead to "evolution" but I think this is a case that highlights genome plasticity; the genome expresses itself phenotypically based upon the environment in which it develops.

Thu, 22 May 2008 07:26:00 UTC | #174196

Bonzai's Avatar Comment 22 by Bonzai

Mike,

Well whether it is the same house or they can be meaningfully said to be in the same neighbourhoood would depend on how you measure distance in the phase space, It is probably true that set of characteristics being measured are not good enough for that purpose, but maybe they are. The article doesn't say,

I don't know if the purpose is to try to reconstruct evolutionary history. If that is the purpose it wouldn't be sufficient to simply knowing that you have reach a particular state, even if you can narrow it down. There are many possible paths to reach it and they cannot be ruled out apriori.

When you bring in relationship with other populations then of course there is no "reversal", for that means restoring the "environment" of the species to an earlier state as well. This is never implied.

I can be wrong, I think while it is not meaningful to talk about the direction of evolution, it does make sense to talk about the proximity of species, based on some measure. If that is true that all they are saying is that the fish evolved away from a given state and then come close to it again. Think of the original state as a point. Draw a big circle and a small circle centered at the point. At time = t, species is in a state specified by a point outside the big circle (far from the center) and then at time s, s > t, organism is found at another state, which is inside the smaller circle (closer to the circle). That is all I mean.

Thu, 22 May 2008 07:27:00 UTC | #174197

severalspeciesof's Avatar Comment 23 by severalspeciesof

Comment #183492 by epeeist says

And four more gaps opening...


I share your observation, though fortunately for us, the individual gaps are getting smaller, and we should point that out whenever we can.

Thu, 22 May 2008 07:36:00 UTC | #174200

antcowan's Avatar Comment 24 by antcowan

The term for "Reverse Evolution" is Atavism or Throwback and can be seen on whales with legs Horses with extra toes and so on. They usually disappear through selection but this looks like a rare case were its known to be favored.

Thu, 22 May 2008 07:54:00 UTC | #174209

Quine's Avatar Comment 25 by Quine

I agree with [Edit: rodviking,] Dax and Mike O'Risal. Because of the political situation, you can't ignore the impact of terms and phrases taken out of the scientific context and dropped into the public media. The public will hear "reverse evolution" and instantly get the impression that the must be a "forward" direction that was "reversed." We are struggling to get the public to have even a basic understanding of the true nature of evolution, and this does not help.

P.S. Does the average person ever think of his/her neighborhood in terms of a "phase space"?

Thu, 22 May 2008 07:56:00 UTC | #174211

Lionel A's Avatar Comment 26 by Lionel A

'Reverse Evolution' is an unfortunate, and surprising, term for a biologist to use, one that is not even 'wrong' for it is nonsense and in this a charge of pedantry is inappropriate Bonzai.

Taking your example of having to back track because of an unexpected road closure you are most unlikely to retrace your path exactly, your steps, or tyre treads will almost certainly trace out a fresh path and the points of contact of tyre to road will likely be different at each stage and the time of course would have moved forward and not returned you to some earlier time.

Evolution is tied to time which in this sense does have direction. The fish has to evolve into a new state that resembles some ancestor but which is not exactly as that ancestor.

Mike O'Risal in #183515 has explained the matter to some satisfaction.

Thu, 22 May 2008 08:06:00 UTC | #174215

mordacious1's Avatar Comment 27 by mordacious1

Well, the article said that before the clean-up, 6% had the armor plating, now 49% . I wouldn't call that reverse evolution even if I liked the term. If 0% had armor plating previously, then that would be something. In this case, natural selection is just allowing those with armor to thrive more, reverse evolution? I think not.

Thu, 22 May 2008 08:06:00 UTC | #174216

Quetzalcoatl's Avatar Comment 28 by Quetzalcoatl

mordacious1-

I tend to agree with you on this.

Thu, 22 May 2008 08:09:00 UTC | #174219

Szymanowski's Avatar Comment 29 by Szymanowski


Well, the article said that before the clean-up, 6% had the armor plating, now 49% . I wouldn't call that reverse evolution even if I liked the term. If 0% had armor plating previously, then that would be something. In this case, natural selection is just allowing those with armor to thrive more, reverse evolution? I think not.


"Natural selection is allowing X to thrive more" - that is evolution. A change in allele frequencies over time, as Wiki says: "the process of change in the inherited traits of a population of organisms from one generation to the next".

The "reverse" part of this is simply describing this change in terms of its similarity to more remote ancestors of these fish. It's a useful description even though it doesn't mean that any process has reversed in direction.

Thu, 22 May 2008 08:15:00 UTC | #174222

mordacious1's Avatar Comment 30 by mordacious1

Szymanowski
Yes, I agree with you. It is just reverse evolution is such a misleading term. You could use it for the ebbs and flows of all species on the planet, ie. All species are progressing and reversing continuously. More food this year, the species grow larger, next year smaller. I would only use this term if something disappeared then reappeared because it was necessary for the species to survive.

edit: No, I changed my mind, I wouldn't use this term ever.

Thu, 22 May 2008 08:26:00 UTC | #174228