Christian Evolutionist:

[DallasApple]

That's why they out number us so much and live in every possible place on the planet. Not bad for such 'primitive' things.
On the plus side we couldn't live without our bacteria, so they aren't all bad.

Be proud of your Mutant-ness, it makes you unique.

wa:do

Yep..just like with people I suppose..There is good bacteria and bad bacteria.(plus you definately don't want an overgrowth of bacteria!..Can you say yeast infection!! OUCH!!)

Love

Dallas

 

[challupa]

A few posts back when you were talking about the water and inability to drink it without getting sick, Auto said it was about evolution and Penquin said it was developing antibodies. I am a little confused by that. I thought that mothers passed down antibodies through their milk for example. Would that have anything to do with the children being able to drink the water? Or is this totally not how it works.

 

[challupa]

Also, when talking about bacteria being able to mutate fast enough to become antibiotic resistent, is that what the insects are doing when they become immune to the poisons? Is it the same thing?

 

[Autodidact]

Also, when talking about bacteria being able to mutate fast enough to become antibiotic resistent, is that what the insects are doing when they become immune to the poisons? Is it the same thing?

Absolutely. So using that as another example. No single mosquito starts out vulnerable to insecticide and then becomes immune to it. What happens is, a baby mosquito is born with a mutation that makes it not susceptible to the insecticide. Most of the other mosquitos die from the insecticide, while this baby lives and reproduces. All of its offspring have the mutation, and next thing we know we have a million insecticide-resistant mosquitos.

 

[painted wolf]

A few posts back when you were talking about the water and inability to drink it without getting sick, Auto said it was about evolution and Penquin said it was developing antibodies. I am a little confused by that. I thought that mothers passed down antibodies through their milk for example. Would that have anything to do with the children being able to drink the water? Or is this totally not how it works.

The problem is bacteria can change so that anibodies don't work.
Bacteria can also change so that they are no longer dangerous to the host.

Larger organisms that cause waterbourn illness have their own ways past the hosts defenses.
(in other words its all very complicated)

Also, when talking about bacteria being able to mutate fast enough to become antibiotic resistent, is that what the insects are doing when they become immune to the poisons? Is it the same thing?

Insects can't change their mutation rate or swap plasmids like bacteria do. They do however reproduce extremely rapidly. This is where they get their edge.
They can have several generations a year... when the pressure to survive is focused on pesticide resistance then you have a very strong selective direction. Any resistance is quickly magnified in each generation as they will be only ones to breed.

wa:do

 

[9-10ths_Penguin]

A few posts back when you were talking about the water and inability to drink it without getting sick, Auto said it was about evolution and Penquin said it was developing antibodies. I am a little confused by that. I thought that mothers passed down antibodies through their milk for example. Would that have anything to do with the children being able to drink the water? Or is this totally not how it works.

Yeah, that could be. Good point.

Insects can't change their mutation rate or swap plasmids like bacteria do. They do however reproduce extremely rapidly. This is where they get their edge.
They can have several generations a year... when the pressure to survive is focused on pesticide resistance then you have a very strong selective direction. Any resistance is quickly magnified in each generation as they will be only ones to breed.

Actually, I remembered a bit of discussion about some insect species from a science radio show last year: there are some insect species with intermittent food supplies that switch reproductive methods. When food is plentiful, they breed asexually and only produce females (to increase their numbers as quickly as possible - get while the gettin's good, basically - they're actually born pregnant).

When the food supply starts to dwindle, they start to produce both males and females, which then breed sexually (to encourage as much genetic variation as possible so that at least some of their descendents will be able to survive).

I suppose that the two different modes of reproduction would have different associated mutation rates, however, I doubt that this would be the deciding factor in which strategy is adopted.

 

[painted wolf]

Good point. Sexual reproduction increases the chances of mutations.

wa:do

 

[challupa]

Absolutely. So using that as another example. No single mosquito starts out vulnerable to insecticide and then becomes immune to it. What happens is, a baby mosquito is born with a mutation that makes it not susceptible to the insecticide. Most of the other mosquitos die from the insecticide, while this baby lives and reproduces. All of its offspring have the mutation, and next thing we know we have a million insecticide-resistant mosquitos.

Thanks, I wish we had this ability to fast track mutations to keep up with all the bugs that like to get us sick.

 

[challupa]

The problem is bacteria can change so that anibodies don't work.
Bacteria can also change so that they are no longer dangerous to the host.

Larger organisms that cause waterbourn illness have their own ways past the hosts defenses.
(in other words its all very complicated)


Insects can't change their mutation rate or swap plasmids like bacteria do. They do however reproduce extremely rapidly. This is where they get their edge.
They can have several generations a year... when the pressure to survive is focused on pesticide resistance then you have a very strong selective direction. Any resistance is quickly magnified in each generation as they will be only ones to breed.

wa:do

Well that explains why bacteria is so hard to control. Is this how it is with viruses too?

 

[challupa]

Yeah, that could be. Good point.


Actually, I remembered a bit of discussion about some insect species from a science radio show last year: there are some insect species with intermittent food supplies that switch reproductive methods. When food is plentiful, they breed asexually and only produce females (to increase their numbers as quickly as possible - get while the gettin's good, basically - they're actually born pregnant).

When the food supply starts to dwindle, they start to produce both males and females, which then breed sexually (to encourage as much genetic variation as possible so that at least some of their descendents will be able to survive).

I suppose that the two different modes of reproduction would have different associated mutation rates, however, I doubt that this would be the deciding factor in which strategy is adopted.

Well that's handy!! Is this the same thing as when ants start making more of a certain type of ant for the hill depending on circumstances eg. warrior ants. They seem to know when a certain type of ant is needed and the next batch will be predominately that type to meet the needs of the hill. I find that to be fascinating and it isn't hard to see why insects have been able to survive and multiply so well for millenia.

 

[challupa]

Good point. Sexual reproduction increases the chances of mutations.

wa:do

Ah ha now we've come a full circle. In this world of mutating bugs and bacteria it became important for us humans to sexually reproduce so we could mutate fast enough to keep up. If I was a creationist I could say God made man and woman and let them reproduce because he knew they would need to in order to survive. But does that mean God knew about evolution? That would mean he approves! Hmmm Sorry, that was kinda circular without a whole lot of logic. :run:

 

[painted wolf]

Viruses can be just as bad as bacteria if not worse.
(many viruses however don't change much over time, they breed slowly and some fuse with their host for years or even the whole lifespan of the host, getting passed down in generations)
Viruses are a many splendored thing.

Well that's handy!! Is this the same thing as when ants start making more of a certain type of ant for the hill depending on circumstances eg. warrior ants. They seem to know when a certain type of ant is needed and the next batch will be predominately that type to meet the needs of the hill. I find that to be fascinating and it isn't hard to see why insects have been able to survive and multiply so well for millenia.

That only happens with social insects like ants. Castes are the result of first if the larva was fertilized or not. (fertilized eggs become girls, unfertilized eggs become boys)
Secondly it depends on how the daughter is raised as a pupa. If fed the right way it can become a queen, or a soldier (depending on when the food is given and/or stopped) if nothing special happens then she becomes a worker.
This doesn't happen in all ant species however... it is a highly evolved trait found in relatively few species. In most ants age determines what job the worker does. Older ants getting the more dangerous jobs.

wa:do

 

[challupa]

Viruses can be just as bad as bacteria if not worse.
(many viruses however don't change much over time, they breed slowly and some fuse with their host for years or even the whole lifespan of the host, getting passed down in generations)
Viruses are a many splendored thing.


That only happens with social insects like ants. Castes are the result of first if the larva was fertilized or not. (fertilized eggs become girls, unfertilized eggs become boys)
Secondly it depends on how the daughter is raised as a pupa. If fed the right way it can become a queen, or a soldier (depending on when the food is given and/or stopped) if nothing special happens then she becomes a worker.
This doesn't happen in all ant species however... it is a highly evolved trait found in relatively few species. In most ants age determines what job the worker does. Older ants getting the more dangerous jobs.

wa:do

I find that fascinating. Humans really aren't all that well adapted to survival are they. At least not to the degree some other species are.

 

[painted wolf]

Well, we have adapted in different ways.
We use tools to help us in a much more extended way than other animals do.
Our brain and our social structure are our big adaptations.

Actually I would go so far as to say that our really big advantage, the one that lets us use our brains is our thumbs. We have a precision grip that is much more delicate than any other animals. That lets us use our big brain to design better tools and to manipulate our world.

wa:do

 

[challupa]

Well, we have adapted in different ways.
We use tools to help us in a much more extended way than other animals do.
Our brain and our social structure are our big adaptations.

Actually I would go so far as to say that our really big advantage, the one that lets us use our brains is our thumbs. We have a precision grip that is much more delicate than any other animals. That lets us use our big brain to design better tools and to manipulate our world.

wa:do

Yes we have learned how to manipulate our world pretty good. Actually I am always amazed at what we think of and invent.

 

[Jet Black]

I find that fascinating. Humans really aren't all that well adapted to survival are they. At least not to the degree some other species are.

humans are generalists, and in the long term that's undoubtedly the best position to be in. Species that adapt too well to a specific environment are at danger of being driven extinct if the environment changes in a way they cannot cope with - the more extreme the adaptation, the easier extinction becomes. generalists on the other hand are more flexible and can live in varying environments much more easily, since they are not so reliant on specific conditions/food sources.

you might ask "why aren't we all generalists then" - well evolution doesn't work like that. There is no foresight. Adaptations that result in higher than average offspring will proliferate through the breeding population will become dominant, even if those adaptations later on become a problem when the environment changes.

 

[Jet Black]

Good point. Sexual reproduction increases the chances of mutations.

wa:do

no, it doesn't really. Sexual reproduction increases the pool of genes, and means that if you don't have the genes to survive a certain situation, but another individual does, then you can mix genes and then more of your own genes have a chance of being in a body alongside genes which help them survive a particular situation. For example if it's getting colder over time and a particular male's genes code for longer fur, but a female's genes code for shorter fur, then if they breed, then some of the offspring of the female will have genes for longer fur. The cost of course is that only half of the female's genes are in any one offspring, as opposed to all of them.

So in the aphids, when conditions are good, they breed asexually, because all of their genes will make it to the next generation, and those genes will most likely survive. When under pressure, it is advantageous to mix, because even having half of your genes passed on is better than none at all.

sexual reproduction doesn't increase mutation rates, it increases possible combinations, since the genes in the offspring are no longer limited to a single parent.

This is in pretty simplistic and unscientific terms though, just to give you an idea of what is going on.

 

[Jet Black]

No, I wouldn't emphasize that. What happens is that if a mutation is favorable, that individual gets to survive and have babies, so that mutation sticks around in the population. If you don't fit your environment, you die without offspring, and so does that mutation.

No, rather that if you were living in the wrong environment (before sunscreen and houses) you'd have died before you had kids, and that would be the end of the whitey-white mutation.

note that death is not required - just differences in reproduction rates. If you have a gene that results in you having greater than the average number of surviving, breeding offspring, then that gene will spread in the population.

 

[painted wolf]

sexual reproduction doesn't increase mutation rates, it increases possible combinations, since the genes in the offspring are no longer limited to a single parent.

actually it also increases the chance of some mutations.
sexual reproduction includes a lot of unzipping and re-zipping chromosomes and a lot of crossover.
This is how you get mutations like Polyploidy and Aneuploidy.
Chromosomes ending up in the wrong place either too many or too few. (Downs syndrome for example)

Sex can also weed out harmful mutations from a population. So its a very fun system.
It absolutely increases the genetic diversity of the population.

wa:do

 

[Autodidact]

We've derailed a bit away from the evidence, to understand the theory better. This is fine, because it has been my experience that once they understand it, many people accept ToE, because it just makes so much sense. If you've got variation, and you've got selection, it's hard to see how it wouldnt' happen. Or, as T.H. Huxley is said to have said upon hearing it, while slapping himself on the forehead, "How extremely stupid of me not to have thought of it myself." So this discussion is good.

However, I did promise evidence, so will continue. [as so often happens, creationists have little interest in it. I think they find it easier to deny its existence if they don't look at it.]

So far I think we've had the age of the earth, and nested hierarchy of life. Next: DNA.

It's important to remember that Darwin knew very little about genetics. Mendel's work had been temporarily lost. He had spent a lot of time talking to pigeon breeders, so understood the nuts and bolts of breeding. But no one at that time knew anything about what causes offspring to resemble their parents. For ToE to work, there has to be some mechanism that causes organisms to reproduce inexact copies of themselves, and this mechanism should be the same for all organisms.

I think you can see why there has to be such a mechanism, because ToE is premised on a range of slightly differing offspring that natural selection is going to work on. As to why it should be universal, remember that ToE says that all life on earth is descended from a single ancestor. Whatever it is that got that ancestor to replicate, is the thing that is passed down through all of Biological history.

Also bear in mind that although we know about DNA now, there's no necessity for reproduction to be based on it. There could have been some other kind of self-replicating molecule, some other basic mechanism for reproduction.

But there isn't. 100 years after Darwin's work, we came to understand the mechanism that causes descent with modification, and exactly how it results in inexact copies of parents.

Further, every living thing on earth that has ever been found turns out to reproduce using DNA. Wow. That's a huge prediction fulfilled, just enormous. It's millions of predictions. If I read a story tomorrow that says that scientists have discovered giant worms in a cave in Brazil, bacteria in Antarctica, or a giant shark in the Mariana trench, I can predict they will reproduce using DNA, based on ToE.

That's just the fact that there is such a thing. It turns out that by decoding DNA we learn volumes about how organisms are related--more on that later. My point in this post is another huge prediction confirmed.