Metabolism, Thinking, and Age

[kaos]

Does having a higher metabolism...

 

...make you age faster? Which in turn could make your life shorter?

...make you think faster?

 

My thinking behind this is that metabolism is simply defined as the rate at which chemical reactions occur in an organism. So if these reactions happen fast, wouldn't that mean that you age faster? Or is aging not controlled by chemical reactions?

 

And about thinking faster. Isn't thinking something to do with chemical reactions in the brain? Or is it electronic impulses? And are the electronic impulses controlled by chemical reactions?

[SkepticLance]

Longevity is governed by evolution, and that operates on whatever age is required for successful reproduction, rather than speed of metabolism.

 

An interesting experiment a few years ago looked at longevity in fruit flies as a function of reproductive age. The experimenters bred fruit flies over many generations. As soon as the larvae metamorphosed into adults, they were separated into male and female, preventing mating. They permitted gender mixing, and mating only towards the end of the fruit flies reproductive life. Most were not able to reproduce, which didn't matter since the few that did produced lots of offspring.

 

Each generation, the separation was prolonged a little more. Clearly, we would expect that adaptation would extend reproductive life as a response to this evolutionary pressure. However, in addition, total longevity extended substantially also. The experimenters were breeding long lived fruit flies.

 

Conclusion : longevity is determined by however long the organism has to live to breed successfully, and this is driven by evolution.

 

Humans are long lived because we need a long period to develop into adults. Parents need to be around to care for young, and the presense of grandparents also increases survival of those young. Thus we have evolved as a long lived species in order to have grandparents to help in the care of young.

[CanadaAotS]

Have you ever read the Earth King series by Robert Jordan?

 

Its complete fantasy, but interesting still...

 

In it, they have a process using "blood metal" shaped into specific ideograms that could take a certain attribute from someone... like strength, endurance, eyesight, hearing, sense of touch, and including metabolism.

 

Metabolism had the effect of increasing the speed that the reciever percieved the world, so that everything seemed to go in slow motion, and also he could move that much faster. A bad side effect however, was that their life span was reduced. For them, living 1 hour was in their reality living 2 hours...

 

Anyway, this is a complete digression, but I really like the book and I thought I'd mention it.

 

Skeptic: Thats exactly why, through natural (or artificial depending on how you look at it) selection, as parents have their children later and later in life longevity is increasing. Read about it in an article in Discover magazine, it said longevity is naturally increasing at about 25 years every century.

[kaos]

Metabolism had the effect of increasing the speed that the reciever percieved the world, so that everything seemed to go in slow motion, and also he could move that much faster. A bad side effect however, was that their life span was reduced. For them, living 1 hour was in their reality living 2 hours...

 

Thats very similar to the movie clockstoppers. What I was asking though, has nothing to do with reproduction. I'm talking about how your body tells time. How does your body know when to start puberty. How does your body know when certain physical events should start and stop?

[SkepticLance]

CanadaAotS said :

 

Thats exactly why, through natural (or artificial depending on how you look at it) selection, as parents have their children later and later in life longevity is increasing

 

Sorry, that's not correct. It is true that longevity is increasing, but this is not genetic - not any form of biological evolution. All that is happening is that we are removing many causes of early death, so that average lifespan grows. We are not living longer. Just less dying young.