Thread: IMMUNITY ?

Hi , this is kind of like the chicken and the egg question BUT, what came first, the disease or the immunity ?

The reason we have an immune system is to resist diseases, yes ? No diseases no immune system ?

But how come diseases didn't wipe out life before the immune system was developed ?

BARCUD

Oh by the way, what came first, the chicken or the egg guys ? seriously :?

i see we have the familiar confusion between the immune system and immunity

obviously immunity can't come before the disease, but there's no reason why the immune system couldn't have developed for totally different reasons, e.g. as a way of recognising the "self" from the "outside"

heh I love this kinda question


(this is purely guesswork)
Immune system came first it will have been developed as a simply method of regulating what gas came in and out of the single celled organism, as the organism evolved into more complexness and needed more nutrients the guard would become more of a system and more complex while at the same time viruses would arise, from there it's a continuous cyle for the past 2billion years



and to the other question Both;
Technically the chicken came first, an egg of something, (probably a fluffy lizard) would have hatched a chicken thing, meaning the chicken comes first from a lizard egg, BUT if you count the egg as the start of the chicken empire then the egg came first
so as always it's up to you

Originally Posted by BARCUD

Hi , this is kind of like the chicken and the egg question BUT, what came first, the disease or the immunity ?

The reason we have an immune system is to resist diseases, yes ? No diseases no immune system ?

But how come diseases didn't wipe out life before the immune system was developed

Neither disease nor the immune system emerged in a short space of time. They evolved together. They are processes in constant competition. We could arguably trace the first "immune responses" to the competition between differing species of single celled life. The first "infection" to any invasion by a single celled life form of a multicellular colony of a differing species.

It is certainly true though that in the case of the mammalian immune system certain things like the TLR, which are partially retained in arthropod evolution as well, suggest they were selected for in the presence of pathogens. There would be no reason for immunity to have evolved without disease.

Evolution of immune systems are complex and involve a lot of exaptation, like the Toll receptor going from being involved in development in arthropods, to acting as a receptor of pathogen associated molecular patterns.

Originally Posted by i_feel_tiredsleepy

It is certainly true though that in the case of the mammalian immune system certain things like the TLR, which are partially retained in arthropod evolution as well, suggest they were selected for in the presence of pathogens. There would be no reason for immunity to have evolved without disease.

Evolution of immune systems are complex and involve a lot of exaptation, like the Toll receptor going from being involved in development in arthropods, to acting as a receptor of pathogen associated molecular patterns.

I've heard that a similar pattern of exaptation occurred with the chemokine system too. I think it's still involved in embryogenesis and perhaps angiogenesis, though I'm pretty hazy on the details of both processes.

Be aware that "immunity" is a broad subject and its effects are not limited to external elements or targets.

I sure don't understand how immunity could regulate gas exchange. Maybe booms could elaborate.

Maybe picky to the original poster, but I'd not say there's a "reason" we have immunity unless you're associating it with intelligent design.

Survival of the fittest. The strong will survive. The weak will perish.


Living things continue to evolve/adapt to survive.
Immunity is more of reactive rather than preventive.
Unless in cases where your body structure is not prone to certain diseases.



Technically, chicken should come first otherwise noone will hatch the egg. But of course as the other guy said, the egg from the lizard came first --- part of the evloution process.

Not really reactive - tho it's selective benefit is reactive to the stressor. The phenomena like all elements favored and evolved via natural selection, had to be established in a genetically sustaining manner 1st, then the established fitness would be selective.

Immunity is no simple phenomena so it's not so easy to understand the progression to current phenomena via evolution.

Originally Posted by Jorge1907

Not really reactive - tho it's selective benefit is reactive to the stressor. The phenomena like all elements favored and evolved via natural selection, had to be established in a genetically sustaining manner 1st, then the established fitness would be selective.

Yes, evolution is more "blindly pro-active". If something works, it survives. But it would be incorrect to think of any evolution changes as being in some manner reactive. That suggests purpose or goal. As Jorge says, selection merely creates the illusion of reaction.