Creationists: Explain your understanding of microevolution and macroevolution

[Alan Kleinman]

Since this reflects a total misunderstanding of what evolutionary change is, the onus is on you to state why you think that it is so. Otherwise it is above my pay grade to figure out the nature of your bizarre understanding of evolution. No version I can think of would fit your assertion. (And I have a fertile imagination.)

Mutations are random events. You compute the joint probability of random events occurring by multiplying their individual probabilities, you don't add these probabilities. Probability theory may seem bizarre to you but if you put a little effort into the subject, it might make sense to you.

 

[pitabread]

What I mean by evolution-friendly is the most ideal environment for an evolutionary process to occur. There are many ways to slow adaptive evolution.

What do you mean by "an evolutionary process"? Do you believe that evolutionary processes need to be strictly adaptive?

 

[Frank Robert]

I'm curious about this, so if hundreds of adaptive mutations have been occurred in the lenski experiments in the course of billions of total mutations observed, could our probability of an adaptive mutations be something like 100/50,000,000,000? Or 1/500,000,000 for the populations of ecoli in the experiments?

This would make sense to me.

That would depend on the environment.

 

[Alan Kleinman]

You need to first define species otherwise you will continue to move the goal posts.

You don't need the concept of species to do the mathematics of DNA microevolution.

 

[Phred]

Here's how you do the math for a single selection pressure adaptive evolutionary process:
The basic science and mathematics of random mutation and natural selection
The mathematics used here is a straightforward application of the "at least one rule" from probability theory. Each adaptive evolutionary step is a binomial probability problem, does the adaptive (beneficial) mutation occur or does it not occur. And each binomial probability problem is linked to the other binomial probability problems by the multiplication rule.

I don't.

And you still haven't posted your equations.

 

[Frank Robert]

You don't need the concept of species to do the mathematics of DNA microevolution.

Your right, I was thinking about macro.

Perhaps you can answer a question. When mutations built up what is the barrier that prevents them from developing into a new species?

 

[pitabread]

You don't need the concept of species to do the mathematics of DNA microevolution.

That wasn't the question though.

The reason I originally asked is that "macroevolution" is typically defined as evolution above the species level (e.g. formation of new species and diversification thereof). And from a gene flow perspective that makes sense, since biologically you either have gene flow in populations or you don't (more or less).

Since you defined microevolution as things that could be demonstrated experimentally, I wondered if you would considered experimental speciation to be microevolution.

 

[Alan Kleinman]

What do you mean by "an evolutionary process"? Do you believe that evolutionary processes need to be strictly adaptive?

Not at all. You can have neutral and detrimental mutations as well. Adaptive evolution is important because it pertains to the evolution of drug-resistant infections, herbicide resistance, pesticide resistance, and failed cancer treatments. Having a good understanding of adaptive evolution gives the scientific framework for addressing these problems. The Kishony and Lenski experiments are good examples of the adaptive evolutionary process. And of course, these are microevolutionary processes.

 

[Ophiolite]

Time for a little light humour, or juvenile sarcasm. It just depends on your point of view.

Creationist Microevolution: the goalposts are moved slightly so that shots on target generally miss.

Creationist Macroevolution: the goalposts are moved from the playing field to a federal prison in the next county, so that the attacking team can't even remember what the game is.

 

[pitabread]

Not at all. You can have neutral and detrimental mutations as well. Adaptive evolution is important because it pertains to the evolution of drug-resistant infections, herbicide resistance, pesticide resistance, and failed cancer treatments. Having a good understanding of adaptive evolution gives the scientific framework for addressing these problems. The Kishony and Lenski experiments are good examples of the adaptive evolutionary process. And of course, these are microevolutionary processes.

I just don't understand the characterization of such experiments being "evolution friendly" though. It seems to imply there is some theoretical "ideal" version of how evolution is supposed to work. But the theory of evolution isn't prescriptive in that sense.

 

[Alan Kleinman]

Your right, I was thinking about macro.

Perhaps you can answer a question. When mutations built up what is the barrier that prevents them from developing into a new species?

I would say that you are not framing the question correctly. The way you should frame the question is what is the barrier that prevents a lineage from accumulating a set of adaptive mutations? That barrier is the multiplication rule of probabilities. This principle is demonstrated by the Kishony experiment. In the drug-free region, he gets a colony of a billion bacteria and one of those members gets an adaptive mutation. That new variant can grow in the next higher drug concentration region but until its colony must grow to a billion members to get a member with the next adaptive mutation. That variant with two adaptive mutations grows in the next higher drug concentration region but its colony must get a billion members for the third adaptive mutation and so on.

 

[pitabread]

I would say that you are not framing the question correctly. The way you should frame the question is what is the barrier that prevents a lineage from accumulating a set of adaptive mutations? That barrier is the multiplication rule of probabilities. This principle is demonstrated by the Kishony experiment. In the drug-free region, he gets a colony of a billion bacteria and one of those members gets an adaptive mutation. That new variant can grow in the next higher drug concentration region but until its colony must grow to a billion members to get a member with the next adaptive mutation. That variant with two adaptive mutations grows in the next higher drug concentration region but its colony must get a billion members for the third adaptive mutation and so on.

Do real world ecosystems mirror the Kishony experiment?

 

[Alan Kleinman]

I just don't understand the characterization of such experiments being "evolution friendly" though. It seems to imply there is some theoretical "ideal" version of how evolution is supposed to work. But the theory of evolution isn't prescriptive in that sense.

There are conditions where adaptive evolution works more efficiently. Factors that slow adaptive evolution is competition and multiple simultaneous selection pressures. The chance of an adaptive mutation occurring occurs on replication of a particular variant.

 

[pitabread]

There are conditions where adaptive evolution works more efficiently. Factors that slow adaptive evolution is competition and multiple simultaneous selection pressures. The chance of an adaptive mutation occurring occurs on replication of a particular variant.

It still doesn't make sense to qualify such an experiment as "evolution friendly", since evolution itself, as you agree, doesn't need to be strictly adaptive.

 

[FrumiousBandersnatch]

So you compute the joint probabilities of random events by the addition of those probabilities? What happens if the two microevolutionary events, each with a probability of occurring are 0.6? Is the joint probability 1.2?

You seem to have misread the comment - it is the microevolutionary events that add, not their probabilities. IOW lots of microevolutionary events accumulate into a macroevolutionary event.

 

[Ophiolite]

You seem to have misread the comment - it is the microevolutionary events that add, not their probabilities. IOW lots of microevolutionary events accumulate into a macroevolutionary event.

Exactly, yet AK seems wholly unaware of this.

 

[Phred]

And... still no equations

 

[Alan Kleinman]

Do real world ecosystems mirror the Kishony experiment?

Real-world ecosystems are subject to many more selection conditions than the Kishony experiment. For example, dehydration, starvation, thermal stress, disease, competition, predation,... Consider the use of antibiotics in the real situation rather than what is described by the Kishony experiment. A 10-day course of antibiotics would select for drug resistance in every case if evolution operated in patients the same way as it does in the Kishony experiment. But most patients have a functioning immune system, so if most of the bacterial population is killed by the antibiotic, the small number of remaining drug-resistant variants are removed by the immune system and you have treatment success.

 

[pitabread]

Real-world ecosystems are subject to many more selection conditions than the Kishony experiment. For example, dehydration, starvation, thermal stress, disease, competition, predation,...

Do you believe that such selective conditions in real-world ecosystems are static?

 

[Alan Kleinman]

And... still no equations

I'll try posting the paper again:

The basic science and mathematics of random mutation and natural selection

Scroll down and click on the "view Full-text" button. That paper gives the full derivation of the equations for adaptive evolution to a single selection pressure.