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OK.. I am trying to find the term (surely there must be one!) that describes a particular phenomenon.. I would love to hear it straight from a scientist, or a person well-versed in biology...
It describes the evolution/adaptation/mutation of a virus, bacteria, fungus, or other pathogen or organism (you could also apply this phenomenon to human & animal behavior..) to a defense (or, offense?) that is put up against it. The thing becomes stronger and finds a way to circumvent the defense- which is usually the presence of a man-made chemical.
For example:
Antibiotics-they worked well at first, then the bacteria gets stronger, we come out with stronger
antibiotics, the bacteria gets stronger, and on and on..
Vaccines (thinking of the flu vaccine mostly)- virus always mutating to get around the vaccines..
Pesticides & fungicides- the pests/ plant pathogens get stronger, then chemicals get less & less
effective over generations
DEET- was effective against mosquitoes for a while- now I hear the mosquitoes are becoming immune
(and I've personally seen evidence of this)
Cancer cells- you get chemo, but then often the cancer cells 'regroup' and come back with a vengeance
This is all I can think of at the moment but you get the idea.
Anyone know...???
Most viruses for which we have vaccines do not become resistant to them. That is because the part of the virus that the vaccine mimics is stable and does not change much. The flu vaccine is in a class by itself, the main problem being we do not have one vaccine that works against all strains. Flu viruses constantly change, but it is not due to exposure to the vaccine just the nature of the virus. This is referred to as antigenic shift and antigenic drift.
Resistance to chemotherapy is also due to natural selection. Many cancers are treated with more than one drug, with the drugs in the "cocktail" working by different mechanisms, in order to try to kill off as many cancer cells as possible before resistance can develop.
Thanks so much!
But I can't seem to find the term in any biology dictionaries online. that's strange.. isn't it a pretty common concept?
Also thank you suzy_q for correcting what I said about viruses... & also for the other info.
Yes, adaptive resistance is the final outcome of evolution via selective inheritance, which is the true answer to the OP question.
Indeed, viruses and bacteria use the same machinations for evolving as did we homo sapiens. Random DNA mutations, which if advantageous to the host organisms for living and thriving in their specific environment, will be naturally selected. In time, due to said thriving of those ogansimx fortunate enough to have acquired that advantageous mutation, what was once the abberation will become the norm. And then finally the only version remaining to produce offspring.
1. Can anyone explain the part how we know how many possible different children combinations we can have, I think it was a number like 69,000. So the probability of having 2 childs with exactly the same dna... is 1 in 69,000.
2. And what is the phenomenon - I think it's something to do with the chromosomes, that we are not equally 25% of our 4 grandparents?
1. Can anyone explain the part how we know how many possible different children combinations we can have, I think it was a number like 69,000. So the probability of having 2 childs with exactly the same dna... is 1 in 69,000.
2. And what is the phenomenon - I think it's something to do with the chromosomes, that we are not equally 25% of our 4 grandparents?
Thanks.
The rate of identical twins is 1 in 285 births, so your 1 in 69,000 is way off.
The process that results in inheriting a bit more or less than 25% of your DNA from a single grandparent is called recombination.
OK.. I am trying to find the term (surely there must be one!) that
describes ... the evolution/adaptation/mutation of a virus, bacteria, fungus, or other pathogen or organism (you could also apply this phenomenon to human & animal behavior..) to a defense (or, offense?) that is put up against it. The thing becomes stronger and finds a way to circumvent the defense- which is usually the presence of a man-made chemical.
For example:
Antibiotics... Flu vaccines ... Pesticides & fungicides ... DEET ... Cancer cells- you get chemo, but then often the cancer cells 'regroup' and come back with a vengeance
Anyone know...???
You already mentioned the word "adaptation".
Also do know that chemo-poisons themselves cause cancer. Then, after the body is already in a doubly-weakened state: 1st. from the cancering process..., & then from whatever surgery and repeated radiation and repeated chemo inflicted, of course the body is so damaged that further cancers are the result, and no wonder most such people, needlessly, die.
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