Evolution questions: round 3

[ScottySatan]

No we don't. We can only reproduce as quickly as we can produce gametes. Bacteria reproduce via binary fission... a single bacteria can produce millions of copies in a few days.
We can't speed up gamete production or gestation.

I'm talking about something completely different. We don't reproduce as quickly when we starve. We live longer, we are less fertile, we mate less often, we don't repair DNA damage as much (i.e. we don't fix mutations). When times are good, we do the opposite and have an exponential growth curve just like bacteria do (we have two babies and all of our babies have two babies.). There is a behavioral and physiological modification that happens. Here are a couple references for one of them:
Silent Information Regulator 2
SIRT1 contributes to telomere maintenance and augments global homologous recombination

The Sir2 pathway exists in every eukaryote, and originated in bacteria.




About modeling the rates of evolutionary change. Maybe I'm not explaining myself properly? The answer to my question is an equation, or a reference to a paper with an equation in it. I think the right answer to my question might be "we can't do that yet". But I'm not sure. Do you know? How close can we get? should I try to rephrase the question?

 

[ScottySatan]

Many insects can reproduce both sexually and asexually.

wa:do

I think Nerds and the Swiss also reproduce by asexual budding.

 

[painted wolf]

I'm talking about something completely different. We don't reproduce as quickly when we starve. We live longer, we are less fertile, we mate less often, we don't repair DNA damage as much (i.e. we don't fix mutations). When times are good, we do the opposite and have an exponential growth curve just like bacteria do (we have two babies and all of our babies have two babies.). There is a behavioral and physiological modification that happens. Here are a couple references for one of them:
Silent Information Regulator 2
SIRT1 contributes to telomere maintenance and augments global homologous recombination

The Sir2 pathway exists in every eukaryote, and originated in bacteria.

I'm not talking and wasn't talking that aspect, that has nothing to do with what I was talking about with bacteria. I don't know why you were insisting I was wrong when you are talking about apples and I was talking about tosters.

Bacteria can not only exponentially increase their reproductive output but also increase the number of mutations in the next generation "at will". In so doing they increase the chances that they will have a beneficial mutation.

We can not induce mutations into our gametes or embryos or produce them faster. We can choose to forgo mating but our bodies still produce gametes at the same rate. We can't change it.

About modeling the rates of evolutionary change. Maybe I'm not explaining myself properly? The answer to my question is an equation, or a reference to a paper with an equation in it. I think the right answer to my question might be "we can't do that yet". But I'm not sure. Do you know? How close can we get? should I try to rephrase the question?

I already told you..We can't do what you want... We can look backwards and get an idea of when major groups and living species diverged from one another, but we can't give a specific rate of mutations that made it happen.

We can model the rates of neutral changes in species going backward but it's a complex process and it doesn't hold for all genes in the genome. And it only works for Eukaryotes.
Calibration of Avian Molecular Clocks
Molecular clocks
Evolutionary Biology - Max K. Hecht, Ross J. MacIntyre, Michael T. Clegg - Google Books

wa:do

 

[ScottySatan]

I'm not talking and wasn't talking that aspect, that has nothing to do with what I was talking about with bacteria. I don't know why you were insisting I was wrong when you are talking about apples and I was talking about tosters.

Bacteria can not only exponentially increase their reproductive output but also increase the number of mutations in the next generation "at will". In so doing they increase the chances that they will have a beneficial mutation.

I think the confusion comes because; all you initially said is that bacteria can change their rates of reproduction and genetic change and EUKARYOTES CAN'T. I wonder if you were describing a very specific thing with very general words. All I'm saying is that actually, all eukaryotes change their rates of reproduction and genetic change too. Then I gave you two references to prove it. Maybe I should just give you a link to the hits of the database search to show you the 20,000 or so journal articles about it? If this isn't just a difficulty with communication, then I'm baffled by your denial. I really thought this was just going to be a minor correction of syntax to your initial words.

 

[ScottySatan]

I already told you..We can't do what you want...

I didn't remember seeing that. If you did say that and I missed it, I'm sorry. If "we can't do that" is the best the religious forum can provide, I'd like to suggest the work of Stuart Kauffman from the Santa Fe Institute for at least making a very big head start. He made math models of the classical mechanisms of genetic change: point mutations. Modern molecular evolution lumps together all of the classical mechanisms like genetic drift and replicative error into one boat, the point mutation. Check out Stu Kauffman, Mr. Wolf

 

[Agnostic75]

I didn't remember seeing that. If you did say that and I missed it, I'm sorry. If "we can't do that" is the best the religious forum can provide, I'd like to suggest the work of Stuart Kauffman from the Santa Fe Institute for at least making a very big head start. He made math models of the classical mechanisms of genetic change: point mutations. Modern molecular evolution lumps together all of the classical mechanisms like genetic drift and replicative error into one boat, the point mutation. Check out Stu Kauffman, Mr. Wolf

I do not know anything about any of that, but for what it's worth, Wikipedia says:

"Some biologists and physicists working in Kauffman's area reserve judgment on Kauffman's claims about self-organization and evolution. A case in point is the introduction to the 2002 book 'Self Organization in Biological Systems.'"

 

[painted wolf]

I didn't remember seeing that. If you did say that and I missed it, I'm sorry. If "we can't do that" is the best the religious forum can provide, I'd like to suggest the work of Stuart Kauffman from the Santa Fe Institute for at least making a very big head start. He made math models of the classical mechanisms of genetic change: point mutations. Modern molecular evolution lumps together all of the classical mechanisms like genetic drift and replicative error into one boat, the point mutation. Check out Stu Kauffman, Mr. Wolf

Ms. Wolf actually. :sarcastic

Point mutations are just one of several types of mutations... and the majority of point mutations do nothing functionally.

More important are frame-shift, duplication and insertion mutations. With duplication mutations being the most important evolutionarily.

Stuart Kauffman's book sounds interesting but I don't see any experimental or other real world evidence published to back his molecular/mutation claims up. Which is only a small portion of the otherwise quite well reviewed book.

wa:do

 

[painted wolf]

I think the confusion comes because; all you initially said is that bacteria can change their rates of reproduction and genetic change and EUKARYOTES CAN'T. I wonder if you were describing a very specific thing with very general words. All I'm saying is that actually, all eukaryotes change their rates of reproduction and genetic change too. Then I gave you two references to prove it. Maybe I should just give you a link to the hits of the database search to show you the 20,000 or so journal articles about it? If this isn't just a difficulty with communication, then I'm baffled by your denial. I really thought this was just going to be a minor correction of syntax to your initial words.

I'm speaking to a general audience. The language I use here will tend to reflect that.
Neither of your links has anything to do with the discussion.
The first one is on a mutation that influences heart muscle cell production.
The second one is about telomere maintenance, unwanted homologous mutations within an organism and aging.
Did you bother to read either of these? Or do you just not understand what they are talking about?

We can't change the mutation rates in our gametes or, if reproducing by budding, our clones. Nor can we speed up production of gametes and clones.

Bacteria can do this. This is how they are able to develop native antibiotic resistance and other traits so quickly.

Yes, when we are stressed we are not as likely to reproduce mostly due to the fact that our gametes will be of lower quality, but we will produce them all the same. This is not in our control.

wa:do

 

[painted wolf]

bump.

 

[RedOne77]

Not sure if this is the right place, my question is on radiometric dating.

I understand that radioactive isotopes decay at a measurable and constant rate to a specific daughter isotope. But how do scientists know that from the formation of X, the isotopes that they are looking at didn't get there after, or some didn't become lost along the way?

For example, uranium to lead, how do scientists know that X amount of uranium and lead was present at the formation of said rock, and that no new uranium or lead got incorporated, or that no uranium or lead escaped? Same thing with all of them, C14, K-Ar, Ar-Ar, Rb-Sr, and so on.

 

[Sunstone]

Not sure if this is the right place, my question is on radiometric dating.

I understand that radioactive isotopes decay at a measurable and constant rate to a specific daughter isotope. But how do scientists know that from the formation of X, the isotopes that they are looking at didn't get there after, or some didn't become lost along the way?

For example, uranium to lead, how do scientists know that X amount of uranium and lead was present at the formation of said rock, and that no new uranium or lead got incorporated, or that no uranium or lead escaped? Same thing with all of them, C14, K-Ar, Ar-Ar, Rb-Sr, and so on.

Good question.

 

[painted wolf]

Not sure if this is the right place, my question is on radiometric dating.

I understand that radioactive isotopes decay at a measurable and constant rate to a specific daughter isotope. But how do scientists know that from the formation of X, the isotopes that they are looking at didn't get there after, or some didn't become lost along the way?

For example, uranium to lead, how do scientists know that X amount of uranium and lead was present at the formation of said rock, and that no new uranium or lead got incorporated, or that no uranium or lead escaped? Same thing with all of them, C14, K-Ar, Ar-Ar, Rb-Sr, and so on.

You know... it's not my field so I don't really know.

But from what I've heard... samples are carefully chosen to preclude any chance that such things have happened. For example they don't use surface level of rocks but deeper unweathered regions. Several samples are taken from around the rock to check for consistency. They also try to use as many dating methods as possible to cross check dates. So they not only K-Ar but Pb-Pb and U-Pb as well.

wa:do

 

[Looncall]

Not sure if this is the right place, my question is on radiometric dating.

I understand that radioactive isotopes decay at a measurable and constant rate to a specific daughter isotope. But how do scientists know that from the formation of X, the isotopes that they are looking at didn't get there after, or some didn't become lost along the way?

For example, uranium to lead, how do scientists know that X amount of uranium and lead was present at the formation of said rock, and that no new uranium or lead got incorporated, or that no uranium or lead escaped? Same thing with all of them, C14, K-Ar, Ar-Ar, Rb-Sr, and so on.

Some minerals exclude certain elements when they form so one knows that they started out as a "blank slate". Knowledge of geochemistry provides rich opportunities for ingenuity.

There is a lot of good, easily understood info on the web. Just avoid creationist sites, they lie.

Painted Wolf's comments are well worth attending to.

 

[~Amin~]

So, have fun... all honest questions are welcome!

All the best in your studies, my question, it is suggested that human chromosome 2 is a result of the fusion of 2 primate chromosomes, is this a fact? that definitely there was a fusion? if so then would the subject in which there was fusion, have an immediate transformation in appearance?

 

[RedOne77]

You know... it's not my field so I don't really know.

But from what I've heard... samples are carefully chosen to preclude any chance that such things have happened. For example they don't use surface level of rocks but deeper unweathered regions. Several samples are taken from around the rock to check for consistency. They also try to use as many dating methods as possible to cross check dates. So they not only K-Ar but Pb-Pb and U-Pb as well.

wa:do

I was afraid this was a little too much out of your line of study. I found some stuff online that suggests that certain rocks aren't permeable to certain elements, sort of analogous to the plasma membrane's selective permeability, so you know that for those rocks specific elements are the original and only the original.

One thing that you might be more familiar with is C14, as it is used to date bones and is the most famous. Apparently the carbon content in the atmosphere plays an important role in determining the age; scientists use correcting models for atmospheric carbon content at time of death to determine age when using C14. But how do they know what the C14 content was at that particular time and place? I know there are ice cores that trap air samples throughout the years, but I can't imagine scientists taking such a small sample and authoritatively using it for the entire globe for that time period. Do you know if there are other local ways to find out carbon content in years past? They must, since they have charts of C levels millions of years ago and ice cores don't go that far, or do they just estimate it somehow?

 

[RedOne77]

All the best in your studies, my question, it is suggested that human chromosome 2 is a result of the fusion of 2 primate chromosomes, is this a fact? that definitely there was a fusion? if so then would the subject in which there was fusion, have an immediate transformation in appearance?

PW can probably tell you more, but it is pretty much a fact. Chromosomes have structures called centromeres at the center and telomeres at the ends. Our chromosome #2 has telomeres in the center, with a centromere (one inactive) on each side. I can't recall the numbers, but scientists have determined which chromosomes of the other apes were fused to produce our #2.

A site that might help you out: Chromosome fusion

 

[fantome profane]

would the subject in which there was fusion, have an immediate transformation in appearance?

It is my understanding that this would cause little or no change in the appearance (phenotype) of the subject. It is like someone taking two books and gluing them together, it would look very odd having the “covers” of the book in the middle, but it wouldn’t change the plot of either book.

 

[Shermana]

Any links to how the electric eel supposedly evolved? I can't find much besides this....

Scientists Push for Electric Eel Genome Research | GenomeWeb Daily News | GenomeWeb

 

[painted wolf]

All the best in your studies, my question, it is suggested that human chromosome 2 is a result of the fusion of 2 primate chromosomes, is this a fact? that definitely there was a fusion? if so then would the subject in which there was fusion, have an immediate transformation in appearance?

There wouldn't have been an immediate transformation in appearance... our appearance is due to more than just the fusion event. The immediate changes would have been very subtle.

It's as definite as you can get that the fusion happened... there is simply no other explanation for why we would have a chromosome that looks like two fused chimp chromosomes otherwise.
Unless, you go with the idea that God is a sneaky fellow out to trick us. (and I don't)

wa:do

 

[painted wolf]

I was afraid this was a little too much out of your line of study. I found some stuff online that suggests that certain rocks aren't permeable to certain elements, sort of analogous to the plasma membrane's selective permeability, so you know that for those rocks specific elements are the original and only the original.

One thing that you might be more familiar with is C14, as it is used to date bones and is the most famous. Apparently the carbon content in the atmosphere plays an important role in determining the age; scientists use correcting models for atmospheric carbon content at time of death to determine age when using C14. But how do they know what the C14 content was at that particular time and place? I know there are ice cores that trap air samples throughout the years, but I can't imagine scientists taking such a small sample and authoritatively using it for the entire globe for that time period. Do you know if there are other local ways to find out carbon content in years past? They must, since they have charts of C levels millions of years ago and ice cores don't go that far, or do they just estimate it somehow?

The only incident that I know of that has ever significantly changed C14 ratios is the above ground nuclear testing done in the 50's-80's. You can actually tell if someone was alive during of within a certain time period after the detonations.

You can use the formation of corals, sediments and other things to figure out atmospheric CO2 levels... corals (and other inverts) for example need calcium carbonate to form shells and other structures. Carbon dioxide in the atmosphere gets sucked into the oceans and changes the ph... reducing the amount of available calcium... which changes the growth of corals.

Fossilized corals (and other marine inverts) are a fantastic temperature/CO2 monitoring system for the deep past.

wa:do