Starspun

From what I have read on the subject of evolution (which is not much, to be honest) it seems the common theory is that evolution (macro) happens in spurts with big changes taking place in a relatively short period of time. If this is wrong, please correct me.If it is not, read on.
Perhaps this happens because of microevolution. If many little changes occur (micro), then to adjust to these changes, an organism must compensate somehow (macro).
An analogy would be a single person living in a one room house. If he/she get's married and has children, the minor changes to the inside of the house would require a substantial change to the house itself to compensate for the lack of living space. Does this make sense? Also, has this hypothesis already been explored? If so, what were the findings or what can I read to substantiate it, if anything.

Thanks all.

tgamble

Sounds more like Punk Eek to me.

um, no that's not how it works. Evolution applies to populations, not individuals. Second of all, compensate for what? Numourous small changes can add up to large changes. Like renovating a house for example. Add a room here, combine two rooms there, add a skylight etc. Lots of small changes add up to a large change.

No, it doesn't make sense (at least not to me). I doubt it's been explored.

You should visit the talk.origins archive to get a basic introduction to evolution as well as answers to lots of questions and rebuttals to creationist arguments and explosore of creationist deception.

<a href="http://www.talkorigins.org" target="_blank">http://www.talkorigins.org</a>

GeoTheo

I think punk eek is an illusion created by the incompletness of the fossil record. It was presented originally by Gould and Eldridge without a timescale. "Sudden appearance of an organism in the fossil record" is a misunderstood phrase.
It is taken by advocates of ID to mean "appeared there by magic" whereas all that is meant is that appears as a new organism that is not present lower in the strata. The strata layers still show a progression. Just not to a degree that fits the Darwinian idea of small incremental change.
But in a way it does. There is no "sudden appearance" of placental mammals in the cretaceous
or anything like that.
It's just that most living things end up as food and not fossils when they die. The fossil record doesn't necessarily imply any "leaps" in evolution. In fact there are quite a few transitionial forms being discovered all the time.

Starspun

wtf? Who said anything about creationism? It was just a question that went through my mind; nothing more. Thanks for the 'constructive' input.
I'll believe in creationism when...well, never.

GeoTheo

Well my point is there are no "big changes taking place in a relatively short period of time"
I think that is a preposterous idea. You said you believed in it not me. Perhaps you reject creation a priori due to your philisophical beliefs and not your knowledge of biology?

Starspun

Not at all Geo. I believe in what I have read thus far and have seen as evidence, ie., the fossil record. All the pieces will fit into place as time goes by and I get more informed.
thanks for your concern though.

Doubting Didymus

One reason new species appear quickly in the fossil record is not because evolution suddenly turns on, and then switches off again. It is because when we search for fossils, we dig straight down. Think about it: we often have fossil histories for areas often no larger than an acre. Now, since speciation often occurs when one species becomes geologically separated, what generally happens is that one species becomes two species, one of which lived outside of the area that we are looking for fossils in. If one of the two species becomes much more successfull than the other, it is likely that they will spread ouside of the area they live in, and replace the other species. Therefore, if we dig straight down, we should often see a species 'become' a new, considerably different looking, version of its old self.

What has actually happened is not saltation, but the replacement of a species by a recently diverged sister species, which out-competed it and drove it to extinction.

NialScorva

Ok, from my experience with evolutionary algorithms:

You occassionally reach a local maxima in your fitness functions, that is, all the pieces lodge together and can't find any route out of the entanglement. The solution in the evolutionary algorithms is to save the current solution, and either kill off or drasticly re-randomize the current solution and start it running again to let the code search for other potential solutions.

Punctuated equilibrium is the same thing. Think of evolution as a process that fills gaps rather than a process that builds mountains. These "gaps" are environmental niches that animals will try to fill. Some niches are features of the nonliving environment, some are features of other living things. It's kinda like a giant irregular-shaped bowl of randomly shaped objects being gently shaken. Eventually it will settle down and very little movement of the pieces will occur. The pieces have become "well-adapted" to the space provided by the bowl and by the other pieces in the bowl.

Punk eek is the observation that this bowl is occassionally disturbed. A giant meteor will come along and blow the bowl back out of it's settled state. There will be a great deal of movement as pieces readjust.

Similarly, species will evolve to fill all available niches, and very little evolutionary movement will occur while the species are in a relatively packed state. Then something big comes along and forces them to find a new position.

So, punk eek doesn't really say that species will adapt quickly, rather it says there will be long periods were the available space to adapt into prevents them from changing much at all.

Synaesthesia

GeoTheo That is contrary to the scientific consensus. PE was invoked to explain the distribution of morphology, NOT the incomplete distribution fossils. The latter is due to geological considerations, the former to the fact that morphological evolution proceeds at varying rates in various circumstances.

Oolon Colluphid

I don’t doubt that allopatric speciation is perhaps the main sort; nor do I doubt that macroevolutionary patterns may show stability followed by sudden change, for a variety of reasons.

Conversely however, no serious advocate of punk eek thinks (afaik) that what’s basically going on is changes from generation to generation within populations (even if it is in response to ‘big’ factors such as meteor impacts and separated continents coming together): in other words, normal microevolution.

Therefore, if the fossil record could possibly reveal all organisms across a time period, it would indeed show smooth gradations. In general of course the fossil record does not and cannot, and only creationists require that it should.

So I’m inclined to disagree, Syn. Because wherever the fossil record does show sufficient close-ups, what we see is indeed smooth transitions, as in Peter Sheldon’s Llandeilian trilobites, and here: <a href="http://www.cs.colorado.edu/~lindsay/creation/fossil_series.html" target="_blank">www.cs.colorado.edu/~lindsay/creation/fossil_series.html</a> . I recall from somewhere that one of the classic trilobite punk eek examples -- Phacops, iirc -- has since revealed just such a smooth change.

So much of what seems to be punk eek is due to the nature of the fossil record -- or as Theo put it, an illusion.

Maybe I’ve misunderstood something, and someone can explain, but I don’t see how punctuated equilibrium says anything different from ‘normal’ evolution. ‘Gradualist’ evolution doesn’t mean what Dawkins has called ‘constant speedism’; and allopatric speciation -- followed sometimes by reinvasion by the new-improved-edition -- was obvious even to Darwin. If there are no ‘higher-level’ mechanisms at work (eg species selection -- which is I think “contrary to the scientific consensus” ), what’s the point of punk eek? It doesn’t seem to be a theory, merely an observation... and one already covered by ‘normal’ evolutionary theory. How on earth did biologists explain Latimeria before punk eek came along to save them? Surely not by saying that things will tend to be stable in stable environments…?

Oolon the Dawkinsian