Why do people use the old theory?

[The Janitor]

I have noticed that most 'Evolution Vs Creation' debates particularly on the net will use the older & incorrect version of Evolution or Evolution by ‘phyletic gradualism’ in which species slowly evolve & change over millions of years. However a newer & far better theory was conceived of over forty years ago.

Nowadays most scientists believe in evolution by 'Punctuated Equilibria' (or evolution by jerks as it was called by its critics) in which most macro-evolutionary change occurs during speciation. As we know speciation occurs very quickly (decades, centuries, millennia) & often with small isolated colonies (where mutations can take affect of the general population very quickly) this explains several things.

(i) The gaps in the fossil record, rather than looking for intermediate forms that were alive for supposedly millions of years the intermediates were only alive for extremely short periods of geological time.

(ii) ‘Morphological stasis’ in which many species survive unchanged for millions of years (living fossils) which suggests without speciation evolution is incredibly slow.

(iii) How mutations & recombination can quickly create diverse changes in animals that are then fixed in the population.
For instance rather than thinking of a wing slowly evolving & forming over millions of years think instead of hundreds or thousands of little leaps or jerks (something like... flap of skin to hairy flap of skin to flexible flap of skin to special hairs on flap of skin to special muscles on flap of skin etc…) each leap created by & fixed in a new species.

Has anybody else ever noticed that these debates are often ‘a little behind the times’.

[Keevan_Colton]

Generally speaking....what can you expect when debating totally morons.

[DPDarkPrimus]

Because those are the only arguements that they can think of.

[David]

Please explain how you came to the conclusion the "most" scientists believe in punctuated equilibrium.

[The Janitor]

Sorry I can see how it is a little misleading my post.

Puctuated equilibria is an expansive theory rather than an exclusive theory i.e. some evolution will occur gradually some by punctuated equilibria the only difference in scientists opinions is how much some by a combination of both.

As for scientists believing in punctuated equilibria or not virtually every geneticist or population geneticist I have asked or had a lecture with mentions 'punctuated equilibria' I didn't really know if 'believing' was still an issue.

[David]

Sorry I can see how it is a little misleading my post.

Puctuated equilibria is an expansive theory rather than an exclusive theory i.e. some evolution will occur gradually some by punctuated equilibria the only difference in scientists opinions is how much some by a combination of both.

As for scientists believing in punctuated equilibria or not virtually every geneticist or population geneticist I have asked or had a lecture with mentions 'punctuated equilibria' I didn't really know if 'believing' was still an issue.

Ok

1) I'm a Biology/Chemistry major I know what punctuated equilibia is.

2) If you meant to say that most scientists you know believe in puntuated equilibria thats fine, but I'd like to know how you came to the conclusion that most scientists believe that puntuated equilibria exists.

[The Janitor]

1) Okay, top Dorito.

2) Quite clearly I am saying that most scientists I know 'believe' in punctuated equilibria because that is what I wrote.
However I assume every scientist who believes in evolution & knows anything about the Galapagos mockingbirds (i.e. Darwin) 'believes' in some form of puntuated equilibria.

How did I come up with the notion that 'most' scientists believe in punctuated equilibria?
Well it seems all my lecturers agree with the theory, a variety of famous scientists & books all agree with it & Darwin himself came up with the best example of Speciation.
I really didn't suspect this was still an issue though & so I just wrote 'most' without really thinking about it.
I meant most in my experience I suppose.

Rather than asking subtle questions, why not give me your opinion as a Biology/Chemistry major on the role of punctuated speciation in evolution?
I suspect from your ‘tone’ that you are not a great admirer of the theory perhaps all/most of the scientists you know also disagree?

[David]

2) <snip> I meant most in my experience I suppose.

That has to be the most long winded "yes" I've ever heard.



As for myself, I tend to take the position that a theory must first be proven before it is accepted as fact. S. J. Gould never proved his theory of puntuated equilibrium, so I will continue to be skeptical of anyone who declares it to be the truth. S.J. Gould and company declared his theory to be the truth until he was disproven. I have about the same amount of respect for that kind of thinking as I do for someone that declares aliens are abducting people and they will believe it to be true until someone proves that there are no aliens on earth.

[Cap'n Hector]

Punctuated equlibria would seem to be supported by Darwin's basic data.

The finches' evolution could have happened fairly quickly, as we can't say how fast it happnened.

That said, gradualism works very well...

And I know I'm simplifying this.

[lgot]

I kind like Gould (No, I am not Biologist Major, My younger Brother is and we share books and reading) and I know its quite truth, Punctuated Equilibrium is far from accept by everyone. My Brother is ok with that, but he have teachers who arent and we have friends, biologists as well, who does not. Gould was a rather polemic figure, and not all biologist accepted him well.
I see his theory as helping to explain some problems about the fossiles records, but yeah, it still need most testing and perhaps some adaptation or other...Gould did a good work in my opinion to help to "refresh" darwin and perhaps his "crusade" to that caused this short of elitism to protect his theory...

[The Janitor]

I have to agree that Gould was a bit of a fool but the main admirers of the theory nowadays are people like Professor Dawkins.
In the blind watchmaker (fantastic read for anyone who wants to understand evolution) Dawkins criticizes the way Gould came up with sensational comments like 'Darwin rewritten' this ended up strengthening the hands of Creationist movements (particularly in the US).
I believe Gould did apologize & complain that his comments had been taken out of context but it was too late & many scientists hated Gould for his 'betrayal' & ‘sensationalism’.

However Gould himself is not what is being discussed his ideas are & I doubt anyone can seriously expect that the sheer number of species of Galapagos finches or Pacific Ocean fruit flies formed gradually, it was quite clearly a rapid process involving small colony populations.

[David]

it was quite clearly a rapid process

Ah, so then lets get on to puntuated equilibrium. My reason for bringing up Gould was to show that the originator of the theory never proved it to be fact. So please tell what the mechanism is for both rapidly and drastically altering a specie's DNA so that it would be defined as a different species.

[The Janitor]

First of we will deal with the concept of gradualism in which you get one species which is divided say by an ocean (i.e. founder events) & then both colonies gradually change over time due to natural selection. Eventually you would reach a point that even if members of both colonies were to mate their genomes would be so different as to make no offspring or infertile offspring, they are new species.

Secondly the fuel for natural selection is mutation; a mutation over time has two potential destinies. It will either become fixed in the population or it will ‘die out’.

All that punctuated equilibrium is saying is a well known fact that the chance of a mutation becoming fixed in a population is greater if that population is small. Speciation events almost by definition will include small colony populations.
Mutations will become fixed in the population quicker. Natural selection can work quicker & therefore evolutionary change will be quicker.

The only problem I can see is how much you consider overall Eukaryotic evolution to have been influenced by punctuated speciation.
Gould probably believed all evolution was by speciation & none by gradualism.