MACROevolution vs MICROevolution - what is it?

If you accept that microevolution is evolution within a species, and that macroevolution is evolution beyond a species, then given that it takes many, many generations for macroevolution we have only directly observed macroevolution in very short-lived species, such as bacteria, fruit flies, etc. We have indirectly observed macroevolution in all of life through fossil and genetic evidence.Of course, if you instead define macroevolution as evolution beyond a kind and will claim that "it's still just a bacteria" or "it's still just a fruit fly" then you're using a different definition than everyone else, plus you're using a term with no definition ("kind"). We need to agree on definitions before providing examples makes sense.--Percy

"Micro" is a modifier of "evolution", not of "bacteria". "Micro" refers to the degree of evolutionary change, not to the size of the organism. Bacteria can experience a macroevolutionary degree of change. You might want to check out rule 5 of the Forum Guidelines:

5. Bare links with no supporting discussion should be avoided. Make the argument in your own words and use links as supporting references.

But you seem to be arguing away from the topic. The question is the difference between micro and macroevolution. You seem to want to argue whether macroevolution ever happens.--Percy

A simple Google search of "bacteria macroevolution" returns 148,000 results, and of "bacteria speciation" returns 740,000 results. Perhaps you had a typo when you tried it? How can you tell whether some undefined thing has ever happened? As I said before, if you yourself are defining macroevolution differently from everyone else here then there's no point in arguing whether it has ever happened.But again, whether macroevolution has ever happened is not the topic of this thread. No one here is trying to avoid discussion of the evidence for macroevolution. There are some old threads about macroevolution that are still open:

• Is there evidence for macroevolution?
  
• Fossil Record as the Strongest or most compelling evidence of Macroevolution
  
• Strongest or most compelling evidence of Macroevolution?

Or you could propose a new thread. But I think all this thread is trying to do is reach a consensus on the definition. If you go back to Message 1 you'll see that RAZD was hoping to explore the distinction between micro and macroevolution at quite a detailed level.--Percy

Hi Al,This thread is about how science distinguishes between micro and macroevolution. Providing bare links to creationist websites in an attempt to show that macroevolution doesn't happen is a) contrary to the Forum Guidelines (please, no bare links); and b) irrelevant (it's not what this topic is about).Do you have anything to say about the definition of macroevolution?--Percy

This is as untrue as it has ever been. That's because genetic loss isn't necessary. Where?--Percy

Yes. There's genetic gain and loss happening in populations constantly, and a loss or gain can produce "new varieties or races or breeds or species." And added. Balance, meaning that the amount of genetic information remains unchanged, is probably the least likely possibility. PE is just an illusion created by the nature of the fossil record. Sudden appearance in the fossil record must involve many agencies operating both singly and together - allopathic speciation is just one among many.Faith is fixated on a single scenario and insisting it's the only possible one.--Percy

Just using some ballpark figures, if each individual has 100 mutations, and the probability of a beneficial mutation is 0.000001%, and the population is 1 billion, then there are 1000 beneficial mutations per generation.A recent study showed the probability of beneficial mutations at the SNP level is far higher than thought. I read about this recently, wish I could find it again. Adaptive Mutations in Bacteria: High Rate and Small Effects isn't the study I read about, but seems somewhat similar, and it says in its abstract:

quote:

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We found a rate on the order of 10−5 per genome per generation, which is 1000 times as high as previous estimates,...

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--Percy

A population reduction to 2 or 14 is a far, far more severe bottleneck than anything seen with species like the cheetah. All the species on the ark, even if every gene was heterozygos (a completely unsupported assertion), would have possessed much less genetic diversity than any species alive today that isn't on the edge of extinction. Another completely unsupported assertion.--Percy

I've been following skeptically along because mutations have played a very minor role in the history of breeding, even if you extend the breeding period to 2000 years. And if you're waiting for a specific mutation, then that seems very unlikely. I think all animal breeding programs depend upon manipulation of existing variation, rather than waiting for mutations. Poking around on the web I did notice the some plant breeding programs use chemicals and radiation to induce mutations.--Percy

Here is the original exchange, where Taq is asking that you back up your assertion that "beneficial mutations are due to increases in genetic information": I agree with your claim that "beneficial mutations are due to increases in genetic information", but how does your response about the probability of a beneficial mutation support that contention, or even have anything to do with it?If I could attempt to answer the question myself, I think any mutation that results in an allele not previously in the population must be considered to have increased genetic information. The number of alleles across the population has increased from n to n+1. How could that not be an increase in information?--Percy

Well, duh! That's a given. What good would it do to talk about mutations in a kidney cell or a liver cell? Those mutations would have no chance of propagating throughout the population.So just using some ballpark figures, if each individual has 100 mutations, and the probability of a beneficial mutation is 0.000001%, and the population is 1 billion, then there are 1000 beneficial mutations per generation. So when you say: Apparently untrue.Plus beneficial mutations are more likely than previously thought.--Percy

I was responding to your claim that "every gene was heterozygos", not suggesting it myself. I called your claim "a completely unsupported assertion." Animals then were like animals now, and animals now are not completely heterozygous. The animals on the ark were drawn from existing populations, not specially made by God for the ark. If junk DNA had been functional genes then there would have been a great, great many more genes, and they would have been completely different animals. "Made up" would be more accurate. This is also "made up." Mutations add genetic diversity with every new daughter population.--Percy

In these discussions we're hardly ever talking about somatic mutations. Reproduction, and the mutations that occur in germ cells, are essential parts of evolution. We're talking about evolution here.Repeating what you're spurious objection led you to ignore, so just using some ballpark figures, if each individual has 100 mutations, and the probability of a beneficial mutation is 0.000001%, and the population is 1 billion, then there are 1000 beneficial mutations per generation. So when you say: Apparently untrue.Plus beneficial mutations are more likely than previously thought.--Percy

Not recently, but I have done a little reading about the breeding history of dogs. My recollection is that single breeders within their lifetimes were able to bring about substantial changes/improvements in the qualities they were selecting for. 20-50 years seems a reasonable answer.--Percy

I confess to not having a clear picture of the scenario described here, but it bears repeating that mutation has played an exceptionally minor role in the breeding history of dogs. Most of the diverse qualities in dog breeds come from existing variation.--Percy