Why are we the size we are?

why are ants so small?

why are elephants so big?

why did most prehistoric animals have much much larger sizes?

I thought it was a measure of how long they had been evolving since things start off microscopic but some of the oldest creatures are still small and a skull was found of an extinct caveman similar to us but was 8 feet tall.

Imagine if ants were the size of cats. They would dominate the planet.

5/6/2008 11:42:18 AM

why is this in the soap box?

5/6/2008 11:45:46 AM

gravity (land or water), creature support (endoskeleton vs. ectoskeleton or other), metabolism (with respect to O2 percentage)

5/6/2008 11:46:02 AM

why is this in the soap box?

5/6/2008 11:50:08 AM

-the size we are probably relates with our ability to think

we have enough brain power vs. body mass to control our bodily functions, our muscles, and to constructively think

- ants are small because of the limitations of their ectoskeleton. their shells are made of chitin, which has a limitation on strength vs thickness. as they get bigger the shell has to be thicker and thicker to support their weight making a very large size unmanagable (biggest land spider is about the size of a dinner plate)... however they were bigger in the past (I don't know why... i found a link)


appears it might all be o2 related, I think these are all still researched topics...

here are some links I found on why prehistoric insects were huge

http://www.sciencedaily.com/releases/2007/08/070806112323.htm
http://www.sciencedaily.com/releases/2006/10/061012093716.htm

- I always understood prehistoric animals were larger because of an increased o2 percentage which allows land animals to maintain the metabolism necessary to maintain such large body mass... it is interesting to note though that the largest animal that has ever lives... lives right now... the ocean dwelling blue whale.

[Edited on May 6, 2008 at 11:59 AM. Reason : ...]

5/6/2008 11:51:24 AM

because you can't talk about anything biologically-related without creationists throwing their 2-cents in, thereby starting a religious debate

5/6/2008 11:52:09 AM

omg, take a class

http://en.wikipedia.org/wiki/Island_gigantism

In short, bigger is better if all things are equal. All things are not equal. End of story.

Take woolly mammoth. Stable conditions allowed for emergence of large prolific animal, similar to how dinosaurs came about. Unfortunately for them, unrelated conditions lead to the development of a very effective predator who ate them all.

5/6/2008 11:52:13 AM

Quote :

"-the size we are probably relates with our ability to think we have enough brain power vs. body mass to control our bodily functions, our muscles, and to constructively think"

NO!

http://en.wikipedia.org/wiki/Homo_floresiensis



[Edited on May 6, 2008 at 11:57 AM. Reason : I mean to say, humans could just as well have been 2' tall - unless midgets are retarded, they aren']

5/6/2008 11:55:25 AM

as far as I'm concerned those are the same size

... oh please... you're bringing up the hobbits... come on, they don't even know if they are a different species or not

[Edited on May 6, 2008 at 11:58 AM. Reason : .]

5/6/2008 11:56:14 AM

[Edited on May 6, 2008 at 11:58 AM. Reason : double]

5/6/2008 11:57:51 AM

An acceptable "range" of sizes for which humans could have evolved would range from like 2 feet to infinity. We're temporarily constrained with an upper limit RIGHT NOW because we are newly evolved bipedal animals with weak backs.

5/6/2008 11:58:43 AM

well

i sure would love to see a link...

5/6/2008 12:00:13 PM

It is all relative. Our entire metric of measuring size is human biased. If people were only 1 meter tall we'd be asking the same questions and never know the difference.

I always thought bugs were smaller b/c of their exoskeletons and gravity. Ocean Bugs aka Crustaceans are larger b.c of the less effect gravity has on their exoskeletons in the water.

[Edited on May 6, 2008 at 12:02 PM. Reason : a]

5/6/2008 12:00:19 PM

^

Quote :

"It is all relative. Our entire metric of measuring size is human biased. If people were only 1 meter tall we'd be asking the same questions and never know the difference."

what a stupid response


[Edited on May 6, 2008 at 12:05 PM. Reason : .]

5/6/2008 12:01:40 PM

WTF, that wasn't stupid at all. Maybe trivial logic, which is how all good scientific problems begin.

5/6/2008 12:03:50 PM

I like this thread.

5/6/2008 1:32:31 PM

environment

5/6/2008 1:37:34 PM

food to energy ratio

5/6/2008 1:39:27 PM

Just don't forget that different sized creatures take damage differently. Some may take d4's while some may take d6's or even d8's.

5/6/2008 1:45:48 PM

i can't wait till will wrights spore comes out

it might answer some of these questions

5/6/2008 2:03:02 PM

haha a 'Rat' talking about creature size! hey Rat, what caused you to be a small rodent!? lolololzzolzl

5/6/2008 2:16:41 PM

What about atmospheric density?

5/6/2008 7:18:46 PM

Quote :

"why did most prehistoric animals have much much larger sizes?"

that is an untrue assumption.

5/6/2008 7:53:01 PM

and the ones that did did because they could

elephants wouldnt be as big as they are if there were a lot more of them...but they are big because they are kind of responsible for a larger area...if there were a ton of elephants, either a bunch would die, or they'd evolve into smaller animals to deal with the smaller food supply

[Edited on May 6, 2008 at 7:55 PM. Reason : .]

5/6/2008 7:54:37 PM

Get J_Hova in here to regulate.

5/6/2008 10:42:47 PM

gravity, thermodynamics, electronegativity, statistics, chemistry, etc.

5/6/2008 10:52:43 PM

Duh! God created them that size.

Seriously, when a thread starts talking about hobbits and little green goblins, it's pretty much -> [/thread].

Hollywood ? Reality.

5/6/2008 11:04:45 PM

*sigh

well, no one has talked about "little green goblins"

and as for "hobbits" it's in reference to a recent really interesting find

http://en.wikipedia.org/wiki/Homo_floresiensis

in summary... quit being a douchebag

5/6/2008 11:08:25 PM

Yeah, therefore

Quote :

"It is all relative. Our entire metric of measuring size is human biased. If people were only 1 meter tall we'd be asking the same questions and never know the difference."

is a perfectly valid step to make.

Why on Earth are you making a pretense of being frustrated with other people here? We're not capable of your cognitive ability? Just keep talking down to everyone, I'm sure it's completely justified.

5/6/2008 11:14:42 PM

Quote :

"I thought it was a measure of how long they had been evolving since things start off microscopic"

Really? I'm just surprised by that if you ever took any biology courses in middle or high school. Either way, let me clear this up. What determines any evolutionary outcome? Apparently random mutations brought on by any number of factors that either contribute to, don't outright end, or are neutral in regard to the species' ability to survive.

You have to think that evolution has a final purpose to pose questions such as "what determines X," but since it doesn't, my answer is basically the only one, generally, that can be given.

Now, more specifically,

Quote :

"gravity (land or water), creature support (endoskeleton vs. ectoskeleton or other), metabolism (with respect to O2 percentage)"

isn't a bad first step towards an explanation. To go a lot further would require an understanding of genetics, biology, ecology, etc.

5/6/2008 11:15:57 PM

Quote :

"omg, take a class "

but beyond that...

it's stupid because he's talking about semantics rather than the real issue of biological size

5/6/2008 11:16:58 PM