Time vs. Size: Animal Lifespans Explored

[lusk_2004]

Just a normal guy with a high school diploma here so forgive me if I don't make any sense. In your opinion, how do you think time relates to the size of the being? Instead of thinking about time as night and day, think about it maybe in heartbeats, or steps taken, or breaths. It seems that the larger an animal is, the longer it lives. Do you think that a fruit fly, measuring its time by heartbeats, or how many times it flaps its wings, could live as long a life as we do? This was just an errant thought that crossed my mind, your opinions would be greatly appreciated. Perhaps the theory of relative motion doesn't have so much to do with speed as it does the size of the object travelling.

 

[DavidSnider]

Just a normal guy with a high school diploma here so forgive me if I don't make any sense. In your opinion, how do you think time relates to the size of the being? Instead of thinking about time as night and day, think about it maybe in heartbeats, or steps taken, or breaths. It seems that the larger an animal is, the longer it lives. Do you think that a fruit fly, measuring its time by heartbeats, or how many times it flaps its wings, could live as long a life as we do? This was just an errant thought that crossed my mind, your opinions would be greatly appreciated. Perhaps the theory of relative motion doesn't have so much to do with speed as it does the size of the object travelling.

Lifespan has little to do with how large something is.

Koi fish can live to be 200+ years old. Tube worms can live about the same amount of time. There are some Hydrozoa which are biologically immortal.

http://en.wikipedia.org/wiki/Evolution_of_aging has some pretty interesting theories as to why some creatures have the life spans that they do.

 

[russ_watters]

I have considered the possibility that the brain/body size of an animal affects their perception of time due to the time it takes for nervous system impulses to travel through the brain/body. But I don't know if there is really any way to measure that.

 

[ViewsofMars]

Do you think that a fruit fly, measuring its time by heartbeats, or how many times it flaps its wings, could live as long a life as we do?

A fruit fly lives approximately two weeks. I'm over 50 years old. There is a lady I know that is over 100 years old and her husband is 92.

You can learn about the "Life Cycle of the Fruit Fly" on this website.
http://www.woodrow.org/teachers/bi/1994/life_cycle.html[/URL]

There have been quite a few scientific studies done about fruit flys.

[QUOTE]EMBO reports 8, 1, 46–50 (2007)
doi:10.1038/sj.embor.7400869


[B]A fruitfly's guide to keeping the brain wired [/B]

Maarten Leyssen1, 2 & Bassem A Hassan1

1 Flanders Interuniversity Institute for Biotechnology (VIB)/University of Leuven School of Medicine, Department of Molecular and Developmental Genetics, PO Box 602, Herestraat 49, B-3000 Leuven, Belgium
2 Present address: Institute for Molecular Pathology, Dr Bohrgasse 7, 1030 Vienna, Austria

Abstract

The behaviour of all animals is governed by the connectivity of neural circuits in the brain. Neurodevelopmental and neurodegenerative diseases, as well as traumatic injuries to the nervous system, can alter or disrupt the normal connectivity of the brain and result in disability. In this review, we highlight the contributions of the genetic model organism Drosophila melanogaster to our understanding of neural connectivity in health and disease. In this context we also discuss the research areas in which we believe the fruitfly is likely to be a useful model system in the future.

http://www.nature.com/embor/journal/v8/n1/abs/7400869.html[/QUOTE]

[QUOTE]
[B]With Fruit Fly Sex, Researchers Find Mind-body Connection[/B]
Male fruit flies are smaller and darker than female flies. The hair-like bristles on their forelegs are shorter, thicker. Their sexual equipment, of course, is different, too.

"Doublesex" is the gene largely responsible for these body differences. Doublesex, new research shows, is responsible for behavior differences as well. The finding, made by Brown University biologists, debunks the notion that sexual mind and sexual body are built by separate sets of genes. Rather, researchers found, doublesex acts in concert with the gene "fruitless" to establish the wing-shaking come-ons and flirtatious flights that mark male and female fly courtship.

Results are published in Nature Genetics.

"What we found here, and what is becoming increasingly clear in the field, is that genetic interactions that influence behavior are more complex than we thought," said Michael McKeown, a Brown biologist who led the research. "In the case of sex-differences in flies, there isn't a simple two-track genetic system - one that shapes body and one that shapes behavior. Doublesex and fruitless act together to help regulate behavior in the context of other developmental genes."

How genes contribute to behavior, from aggression to alcoholism, is a growing and contentious area of biology. For more than a decade, McKeown has been steeped in the science, using the fruit fly as a model to understand how genes build a nervous system that, in turn, controls complex behaviors. Since humans and flies have thousands of genes in common, the work can shine a light on the biological roots of human behavior. For example, McKeown recently helped discover a genetic mutation that causes flies to develop symptoms similar to Alzheimer's disease - a gene very similar to one found in humans. . .
http://www.medicalnewstoday.com/articles/57952.php[/QUOTE]

Another very important article is [I]Gene That Doubles Fruit Fly Life Span May Extend Human Life, Say Scientists[/I]. Here's a little snippet from it.

[QUOTE]In both humans and fruit flies, the Indy gene is found where the body stores energy and uses it. Indy absorbs essential nutrients through the gut, concentrates them in the liver, and reabsorbs them via the kidney.

The researchers suspect that humans have more of this type of gene than do fruit flies, given that people are more complex than insects. Whereas manipulation of a single gene affects the fruit fly's life span, in humans it may be necessary to alter multiple related genes.
[url]http://www.advance.uconn.edu/2001/010122/01012202.htm[/url][/QUOTE]

Thanks lusk_2004 for mentioning the fruit fly. :smile:

 

[jamesv87]

russ, I too have considered the idea that the perception of time may differ between organisms, and not only because of the size of the organism (and thus length of time it takes for neural impulses to travel through the body), but also the complexity of neural nets in the brain or CNS. I think its a really interesting idea. So, were this the case, smaller organisms and those with "less to think about" (less complex neural nets) would perceive time to be moving much more slowly than we do, because they are able to transmit more impulses through their neural nets than we can in the same unit time. Perhaps this is why a fly is able to avoid your swats so easily - time may be moving in slow motion for him!

As far as measuring this phenomenon, I am also at a loss. It would be easy to show that stimulus -> response signals transmit through the nervous systems of different organisms at different speeds, but how that affects perception of time seems to be a whole different ball game. IMO, we probably can't answer that with our current understanding of neuroscience, but that's not to say we won't be able to sometime in the future. Your thoughts?

 

[farful]

It seems that the larger an animal is, the longer it lives.

Lifespan has little to do with how large something is.

I think lusk is on the right track. The correlation between lifespan and body mass is actually quite significant.

A smaller organism has a higher ratio of surface area to mass and therefore heat is more readily transported to the surface and dissipated. So to maintain a constant internal temperature, higher rates of energy production is necessary, which translates into more ATP production which means more oxygen needed in the body's system, which means you have a higher metabolic rate, and need more energy consumption... and all this basically results in faster cell division, which leads to the shortening of telomeres, which leads to cell death. This also explains why organisms living in cold areas tend to live longer than ones living in hotter areas (given equal body mass).

Anyway, if you want more in depth answers, I suggest you read http://en.wikipedia.org/wiki/Metabolic_theory_of_ecology.

If your question is strictly about different species sensing time, I think your question is more about whether or not different species have some sort of consciousness/intelligence.

 

[Salbris]

russ, I too have considered the idea that the perception of time may differ between organisms, and not only because of the size of the organism (and thus length of time it takes for neural impulses to travel through the body), but also the complexity of neural nets in the brain or CNS...

This is very obvious when you consider the reaction times of insects. Fly's can decide where to move, turn, etc. much much fast then us. Prey Mantis are the same thing.

Part of it also might be due to the fact that they make decisions very quickly (very little/no thought put into it).