More Questions about Punctuated Equilibrium

[Animore]

Some questions here:

-(How) does this answer the "transitional fossils" question?

-How do the species have so much success, especially after the environment changes so much?

-When it is stated "environmental changes" when explaining this, do they mean the climate is different for the daughter species when compared to the ancestor species or that the climate literally changes significantly, and if it is the former how does it differ from the type of adaptation in gradualism?

Thanks in advance.

 

[Valjean]

That would be "punctuated," as in occurring at intervals.

In a stable environment there is little selective pressure to change. Once a successful design develops, variant offspring get selected out and the form doesn't change. It's only when the design's no longer a good fit -- usually due to environmental/ecological changes -- that variant, better fitting offspring can thrive and begin breeding their new, useful features into the general population.

Do you understand the basics of the theory of evolution, or natural selection, Animore?

 

[Animore]

That would be "punctuated," as in occurring at intervals.

In a stable environment there is little selective pressure to change. Once a successful design develops, variant offspring get selected out and the form doesn't change. It's only when the design's no longer a good fit -- usually due to environmental/ecological changes -- that variant, better fitting offspring can thrive and begin breeding their new, useful features into the general population.

Do you understand the basics of the theory of evolution, or natural selection, Animore?

Yes, I do.

 

[Animore]

That would be "punctuated," as in occurring at intervals.

In a stable environment there is little selective pressure to change. Once a successful design develops, variant offspring get selected out and the form doesn't change. It's only when the design's no longer a good fit -- usually due to environmental/ecological changes -- that variant, better fitting offspring can thrive and begin breeding their new, useful features into the general population.

Do you understand the basics of the theory of evolution, or natural selection, Animore?

Sorry,

Could you please elaborate on your second paragraph?

 

[ADigitalArtist]

Punctuated equilibrium is specifically about evolutionary tempo, how fast changes take place in populations. Punctuated equilibrium isn't necessarily opposed to gradualism, just a stable evolutionary tempo within gradualism in all cases. Re: sometimes change happens faster, either because environmental changes prompt emphasis on traits more quickly, sexual selection does the same, or a combination of them.

 

[Valjean]

Some questions here:
-(How) does this answer the "transitional fossils" question?

What's the question?

-How do the species have so much success, especially after the environment changes so much?

They don't, necessarily. Many will die out. But if a small percentage of their offspring has a feature that benefits them in their new situation, those will tend to do better and leave behind more offspring -- with the new feature.

-When it is stated "environmental changes" when explaining this, do they mean the climate is different for the daughter species when compared to the ancestor species or that the climate literally changes significantly, and if it is the former how does it differ from the type of adaptation in gradualism?

If it changes fast it produces fast adaptations (or extinction), if slowly, then there's no pressure for rapid change and things change gradually.
And it's not necessarily climate change that puts the pressure on; anything, removal or introduction of a predator, for example, can favor changes.

Yes, I do.

Apologies, but I asked because the answers to these questions seem like they'd be obvious to anyone with an understanding of natural selection.

 

[Animore]

just a stable evolutionary tempo within gradualism in all cases

But how could fast-paced change fit in a gradual change? Sorry, kind of a slow learner.

 

[Animore]

What's the question?

Sorry, how does punctuated equilibrium answer the "missing link/transitional fossil" question?

They don't, necessarily. Many will die out. But if a small percentage of their offspring has a feature that benefits them in their new situation, those will tend to do better and leave behind more offspring -- with the new feature.

Ah, that makes more sense. Thanks.

Apologies, but I asked because the answers to these questions seem like they'd be obvious to anyone with an understanding of natural selection.

Well, for the longest time I hadn't wished to learn about evolution at all. A bit of a religious fanatic, and it's only been a short bit where I sat down and tried teaching myself. Plus, I had just heard of this. And I'm a bit of a slow learner. Sorry.

 

[ADigitalArtist]

But how could fast-paced change fit in a gradual change? Sorry, kind of a slow learner.

Fast and slow rates of change can both happen within a single morphological transition depending on what you're talking about. For example, when talking about the evolution of birds, feathers evolved fairly slowly from modified scales, with lots and lots of transitional forms from scales to vaned asymmetrical flight feathers. But flight capable wings in theropod dinosaurs evolved pretty quickly by contrast, as there was a LOT of selective pressure on the helpful traits wings provided (from display and egg brooding to increased running agility, longer jumping, gliding and eventually flight.)
So birds evolved pretty slowly at first, then sped up once certain traits became present. Gradualism and punctuated equilibrium.

 

[Animore]

Fast and slow rates of change can both happen within a single morphological transition depending on what you're talking about. For example, when talking about the evolution of birds, feathers evolved fairly slowly from modified scales, with lots and lots of transitional forms from scales to vaned asymmetrical flight feathers. But flight capable wings in theropod dinosaurs evolved pretty quickly by contrast, as there was a LOT of selective pressure on the helpful traits wings provided (from display and egg brooding to increased running agility, longer jumping, gliding and eventually flight.)
So birds evolved pretty slowly at first, then sped up once certain traits became present. Gradualism and punctuated equilibrium.

Well, that makes a lot more sense. Thanks a bunch.

 

[Valjean]

Sorry,
Could you please elaborate on your second paragraph?

"In a stable environment there is little selective pressure to change. Once a successful design develops, variant offspring get selected out and the form doesn't change. It's only when the design's no longer a good fit -- usually due to environmental/ecological changes -- that variant, better fitting offspring can thrive and begin breeding their new, useful features into the general population."

Do you have any specific questions? Basically:
Reproductive variation: Some offspring are better suited than others to the environment at the time, and tend to have more reproductive success, increasing the frequency of their better suitedness in the general population. If something changes, like colder weather, for example. the occasional offspring with a denser coat is suddenly advantaged. Now they have the better reproductive success, so the mean coat density in the species increases.

But this is basic, peppered moth stuff. Stuff you must have learned in your first biology class in middle school.
So I'm still puzzled by your questions.

 

[Valjean]

Sorry, how does punctuated equilibrium answer the "missing link/transitional fossil" question?

These sound like faux controversies you'd hear from creationists, but I'll take a stab.
Pretty much all species are 'transitional', and any new 'missing link' just creates two more on either side of it.
I think in the early years of our awareness of evolution people looked at great apes, noticed the resemblance, and demanded some evidence of a transitional form.
Apparently the news of transitional forms, as well as many other evidences discovered in the last century and a half, don't seem to have reached certain demographics.

Well, for the longest time I hadn't wished to learn about evolution at all. A bit of a religious fanatic, and it's only been a short bit where I sat down and tried teaching myself. Plus, I had just heard of this. And I'm a bit of a slow learner. Sorry.

Browse: TalkOrigins Archive: Exploring the Creation/Evolution Controversy
Google: video: evolution
Click: Mechanisms: the processes of evolution

 

[Kilgore Trout]

Adaptations that have a greater impact on survival will propagate through a population more quickly, due to individuals having such a trait having a greater chance of survival and passing along these traits.

This is simple, understandable logic, that requires no more complex explanation.

"Transitional" species are a conceptual misunderstanding based on people's tendency for simplistic categorization. Every generation is a "transition" to the next generation. There are no hard lines between one "species" and the next.

This being the case, punctuated equilibrium has no part in explaining transitional species, as the concept has no meaningful connection to evolutionary theory.

 

[Brickjectivity]

I do not think punctuated equlibrium is a good explanation for fossil gaps. There are times when many fossils are preserved and times when not many are preserved. For example in the US southern states in the woods and the hills in the pink clays you can dig up shark teeth and ancient shelled creatures in clay fairly near the surface of the ground, but you will not find many ancient deer bones, bird bones or dog bones in the soil despite their relative plenty over the last five thousand years. They have not been well preserved and have become part of the soil. There is therefore a huge fossil gap, because you dig down through the soil a few feet or ten feet, and suddenly you are looking at the bottom of an ocean.