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Why do animals have shorter lifespans?

Started by ragarth, December 07, 2009, 12:49:03 PM

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ragarth

Or phrased more properly, what mechanism results in animals having shorter lifespans than humans?

Science/Evolution has a few ideas out on this, such as the shorter lifespan being a product of environmental influences upon the genetics of the animal, the shorter lifespan being directly advantageous, or the shorter lifespan being a byproduct of other advantages.

On the religion side of things, however, I'd like to know more.

MariaEvri

from personal observations, Id say the smaller the size, the shorter the life span. And not all animals live shorter lives than humans. Bowhead whales are thought to live more than one hundred years and lets not forget the age old tortoises of th galapagos.

Lets see the scientific explanations of the fellow forum members :)
God made me an atheist, who are you to question his wisdom!
www.poseidonsimons.com

joeactor

Quote from: "MariaEvri"Lets see the scientific explanations of the fellow forum members :)

... because we eat them.

(yum!),
JoeActor

AlP

There's a list of the lifespans of various species here. The Hexactinellid sponge wins at an estimated 15,000 years. That's one creepy looking animal! I think that's a maximum longevity; humans are listed as having a longevity of 122.5 years. I don't know the causes of aging.
"I rebel -- therefore we exist." - Camus

ragarth

That's an interesting site, thank you. :-)

To the critique above, I didn't say all animals, I said 'animals'. I felt it would be assumed that some animals do indeed have longer lifespans than humans: whales, sea turtles, etc. And the assertion that smaller animals live longer based upon size is incorrect, certain forms of captive bird can live in the 100 year range whereas dogs do not have that form of longevity.

Still though, this discussion is lacking the answers I'm really looking for, the religious ones.

AlP

You mean, why would an intelligent creator design an animal with a lifespan shorter than a human? I'm sure I could make something up if it's a problem ;).
"I rebel -- therefore we exist." - Camus

MariaEvri

Quote from: "joeactor"
Quote from: "MariaEvri"Lets see the scientific explanations of the fellow forum members :)

... because we eat them.

(yum!),
JoeActor

do they at least taste good or should I get the sauces ready?
God made me an atheist, who are you to question his wisdom!
www.poseidonsimons.com

karadan

In the case of mammals, i seem to remember there being a corellation between the size of the animal, its lifespan and the frequency of its heart beat. The larger the animal, the less times its heart beats per minute, the longer it lives.
QuoteI find it mistifying that in this age of information, some people still deny the scientific history of our existence.

SSY

I have heard the rough rule of thumb that an animals heart can beat a billion times before it dies. Obviously this is just a rough generalisation, with no actual scientific reasoning, but kinda cool none the less.

Also, why would you come to an atheist website to ask us the religious reasons, for a god we don't believe in, to decide on the length of time an animal lives for?
Quote from: "Godschild"SSY: You are fairly smart and to think I thought you were a few fries short of a happy meal.
Quote from: "Godschild"explain to them how and why you decided to be athiest and take the consequences that come along with it
Quote from: "Aedus"Unlike atheists, I'm not an angry prick

ragarth

Several large breeds of dogs have shorter lifespans than their smaller counterparts

And I see theists post on this forum, so I figured I'd see their reaction. The only christian webforum I know of that gets good volume and allows atheists is christianforums.com, and I stopped posting there because I got fed up with certain types of BS. If you know of a decent forum for discussions such as this, then let me know, otherwise having a creationism/evolution board on here is pointless. I can see the conversation now:

"Creationism sucks, darwin rocks"
"Yup, I agree"
"Decidedly"
"Most certainly!"

Not nearly as fun as a forum like this should be. :-)

McQ

Quote from: "ragarth"That's an interesting site, thank you. ;)

And yes, as far as mammals go, larger animals tend[/b] to live longer than smaller ones. Same is true for many other types of animals, insects, and even plants. But it is a generalization, of course.

There are no perfect or hard and fast numbers for the natural life expectancy of many animals because of the changes in natural habitat over history, in particular the time period in which humans began to actively study and note life expectancies of organisms. Essentialy we changed the rules for life spans just by being here and being predators.

One of the things that does effect life expectancy is size, but not for the reasons you may think. Size makes a difference in how easily an animal becomes a prey animal. Larger animals do have an advantage over smaller ones simply by virtue of their mass. Predatory animals go for the easiest meal they can get. But metabolism and many genetic factors play roles in life expectancy too. Some other information that came to light about ten years ago is here too: http://www.jlr.org/cgi/content/full/39/10/1989

A nice, short, layman's piece can be found here: http://www.tpwd.state.tx.us/publication ... ife_spans/
 
As for religious reasons, there are none. The bible mentions humans living to many hundreds of years from time time of Adam and Eve up until after the flood. According to Genesis, it seems that our becoming carnivores put the kaibosh on those long lives. After the flood, we went down to 70+ years. But since that is all bullshit, it can't be used to scientifically answer the question.

Additionally, human life expectancy was not always this high. Resorting to Wiki (because I'm in a hurry) you can see in the chart on this page how it has increased.
http://en.wikipedia.org/wiki/Life_expectancy

Hope this helps.
Elvis didn't do no drugs!
--Penn Jillette

Higgle

well, humans ARE animals just for the record.

McQ

Quote from: "Higgle"well, humans ARE animals just for the record.

Yep. Mentioned that in my post, just above this one. But a worthwhile point to reiterate.

By the way, welcome to the forum!
Elvis didn't do no drugs!
--Penn Jillette

Ellainix

I don't think animals have modern medicine to the same degree as humans or genuine sanitation.
Quote from: "Ivan Tudor C McHock"If your faith in god is due to your need to explain the origin of the universe, and you do not apply this same logic to the origin of god, then you are an idiot.

templeboy

Quote from: "MariaEvri"Lets see the scientific explanations of the fellow forum members ;)
"The fool says in his heart: 'There is no God.' The Wise Man says it to the world."- Troy Witte