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Author Topic:   What is the evolutionairy theory on the Giraffe?
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 32 of 70 (801)
12-16-2001 1:23 PM
Reply to: Message 30 by redstang281
12-16-2001 12:59 PM


quote:
Originally posted by redstang281:
Why?
As I asked earlier, is it possible that the giraffe's long neck helps the environment in anyway, or no?

1/ If a Giraffe was in a rainforest, its head would constantly be in the interlocking tree canopy. Simply moving is a problem. Restricted view for predator evasion, not to mention flight.
2/ Yes & no, depending on whether your a tree, having your seeds dispersed in Giraffe dung, or an insect sitting on a high leaf about to be eaten.
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 30 by redstang281, posted 12-16-2001 12:59 PM redstang281 has replied

Replies to this message:
 Message 33 by redstang281, posted 12-16-2001 2:32 PM mark24 has replied

redstang281
Inactive Member


Message 33 of 70 (802)
12-16-2001 2:32 PM
Reply to: Message 32 by mark24
12-16-2001 1:23 PM


quote:
Originally posted by mark24:
2/ Yes & no, depending on whether your a tree, having your seeds dispersed in Giraffe dung, or an insect sitting on a high leaf about to be eaten.

Which would help to keep insects from becoming over populated.
Why did just the giraffe's neck grow and not his whole body? Why did he become misproportioned?

This message is a reply to:
 Message 32 by mark24, posted 12-16-2001 1:23 PM mark24 has replied

Replies to this message:
 Message 34 by mark24, posted 12-16-2001 4:21 PM redstang281 has replied

mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 34 of 70 (805)
12-16-2001 4:21 PM
Reply to: Message 33 by redstang281
12-16-2001 2:32 PM


quote:
Originally posted by redstang281:
Which would help to keep insects from becoming over populated.
Why did just the giraffe's neck grow and not his whole body? Why did he become misproportioned?

Not sure of your point as regards insects.
The Giraffes neck grew more than its entire body as this is the most economical way of gaining height. A huge body requires more food than just a long neck. For the Giraffe, a huge body & the extra bones & musculature required to support it is a survival disadvantage compared to a long neck. ie It may cost more to keep than the extra food it brings in.
The Giraffe isn't misproportioned, it is OPTIMALLY proportioned for its lifestyle.
------------------
Occam's razor is not for shaving with.
[This message has been edited by mark24, 12-16-2001]
[This message has been edited by mark24, 12-16-2001]

This message is a reply to:
 Message 33 by redstang281, posted 12-16-2001 2:32 PM redstang281 has replied

Replies to this message:
 Message 35 by Percy, posted 12-16-2001 6:15 PM mark24 has replied
 Message 37 by redstang281, posted 12-17-2001 7:08 AM mark24 has not replied

Percy
Member
Posts: 22388
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 35 of 70 (806)
12-16-2001 6:15 PM
Reply to: Message 34 by mark24
12-16-2001 4:21 PM



Mark24 writes:
The Giraffe isn't misproportioned, it is OPTIMALLY proportioned for its lifestyle.
An interesting question often asked about ID (which I know isn't advocated by Redstang, I introduce it for another reason) is why God's designs are identical with evolution. This often comes up when people question why God would design humans so poorly, eg, why the appendix, why blood vessels in front of the retina, why a body cavity design best suited for horizontal positioning, why tonsils, and so forth. The argument is that good enough designs, vestigial organs, etc, are what one would expect of evolution, not of a divine designer.
Assuming consistent arguments are preferable, could it instead be argued that the giraffe body design is good enough for its ecological niche, rather than optimal?
--Percy
[This message has been edited by Percipient, 12-17-2001]

This message is a reply to:
 Message 34 by mark24, posted 12-16-2001 4:21 PM mark24 has replied

Replies to this message:
 Message 36 by mark24, posted 12-17-2001 1:44 AM Percy has not replied
 Message 38 by redstang281, posted 12-17-2001 7:11 AM Percy has not replied

mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 36 of 70 (807)
12-17-2001 1:44 AM
Reply to: Message 35 by Percy
12-16-2001 6:15 PM


quote:
Originally posted by Percipient:

Mark24 writes:
The Giraffe isn't misproportioned, it is OPTIMALLY proportioned for its lifestyle.
An interesting question often asked about ID (which I know isn't advocated by Redstang, I introduce it for another reason) is why God's designs are identical with evolution. This often comes up when people question why God would design humans so poorly, eg, why the appendix, why blood vessels in front of the retina, why a body cavity design best suited for horizontal positioning, why tonsils, and so forth. The argument is that good enough designs, vestigial organs, etc, are what one would expect of evolution, not of a divine designer.
Assuming consistent arguments are preferable, could it instead be argued that the giraffe body design is good enough for its ecological niche, rather than optimal?
--Percy

I concede the point.
I was just trying to get across the point (badly) that a Giraffe can only be misproportioned when compared to another Giraffe, at least thats what I was trying to say!!
Evolution would be well described as "the search for the optimal design".
While I'm at it, my answers to Redstang are not meant to be absolute truths, just possible/likely scenarios that describe how mutation & natural selection combine to allow variation not allowed by purely sexual (or asexual, for that matter) reproduction.
------------------
Occam's razor is not for shaving with.
[This message has been edited by Percipient, 12-17-2001]

This message is a reply to:
 Message 35 by Percy, posted 12-16-2001 6:15 PM Percy has not replied

redstang281
Inactive Member


Message 37 of 70 (809)
12-17-2001 7:08 AM
Reply to: Message 34 by mark24
12-16-2001 4:21 PM


quote:
Originally posted by mark24:
Not sure of your point as regards insects.
The Giraffes neck grew more than its entire body as this is the most economical way of gaining height. A huge body requires more food than just a long neck. For the Giraffe, a huge body & the extra bones & musculature required to support it is a survival disadvantage compared to a long neck. ie It may cost more to keep than the extra food it brings in.
The Giraffe isn't misproportioned, it is OPTIMALLY proportioned for its lifestyle.

Did you know that the giraffe's body itself is actually smaller than that of a horse?

This message is a reply to:
 Message 34 by mark24, posted 12-16-2001 4:21 PM mark24 has not replied

redstang281
Inactive Member


Message 38 of 70 (810)
12-17-2001 7:11 AM
Reply to: Message 35 by Percy
12-16-2001 6:15 PM


[QUOTE]Originally posted by Percipient:
[b]

Mark24 writes:
The Giraffe isn't misproportioned, it is OPTIMALLY proportioned for its lifestyle.[/QUOTE]
An interesting question often asked about ID (which I know isn't advocated by Redstang, I introduce it for another reason) is why God's designs are identical with evolution. This often comes up when people question why God would design humans so poorly, eg, why the appendix, why blood vessels in front of the retina, why a body cavity design best suited for horizontal positioning, why tonsils, and so forth. The argument is that good enough designs, vestigial organs, etc, are what one would expect of evolution, not of a divine designer.
Assuming consistent arguments are preferable, could it instead be argued that the giraffe body design is good enough for its ecological niche, rather than optimal?
--Percy
[This message has been edited by Percipient, 12-17-2001]
[/B]

The creationist pov of vestigial organs is that we just don't know what they do yet.

This message is a reply to:
 Message 35 by Percy, posted 12-16-2001 6:15 PM Percy has not replied

Replies to this message:
 Message 39 by mark24, posted 12-17-2001 7:52 AM redstang281 has replied

mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 39 of 70 (813)
12-17-2001 7:52 AM
Reply to: Message 38 by redstang281
12-17-2001 7:11 AM


[QUOTE]Originally posted by redstang281:
The creationist pov of vestigial organs is that we just don't know what they do yet.
[/B][/QUOTE]
Wouldn't you be able to determine this by looking at an organism that had the fully developed organ? eg Ruminants. In the case of the caecum (appendix)its for digestion of cellulose. All the other organs in ruminants have the same function as our organs, liver, kidney, lungs. Our caecums produce no hormones or enzymes, & no longer digest cellulose, or anything else for that matter.
The organ IS function-less.
If the caecum has a function, the onus is on creationists to show it, where science has failed. Go on, theorise.
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 38 by redstang281, posted 12-17-2001 7:11 AM redstang281 has replied

Replies to this message:
 Message 40 by redstang281, posted 12-17-2001 12:22 PM mark24 has not replied

redstang281
Inactive Member


Message 40 of 70 (846)
12-17-2001 12:22 PM
Reply to: Message 39 by mark24
12-17-2001 7:52 AM


quote:
Originally posted by mark24:
Wouldn't you be able to determine this by looking at an organism that had the fully developed organ? eg Ruminants. In the case of the caecum (appendix)its for digestion of cellulose. All the other organs in ruminants have the same function as our organs, liver, kidney, lungs. Our caecums produce no hormones or enzymes, & no longer digest cellulose, or anything else for that matter.
The organ IS function-less.
If the caecum has a function, the onus is on creationists to show it, where science has failed. Go on, theorise.

Just because we don't know what it does now, doesn't mean we never will. Tonsils once thought to be useless actually help prevent disease. Those who have had their tonsils removed are actually 4 times more likely to develop Hodgkin’s disease.
But this is getting off topic anyways.

This message is a reply to:
 Message 39 by mark24, posted 12-17-2001 7:52 AM mark24 has not replied

Replies to this message:
 Message 41 by redstang281, posted 12-17-2001 12:25 PM redstang281 has not replied

redstang281
Inactive Member


Message 41 of 70 (847)
12-17-2001 12:25 PM
Reply to: Message 40 by redstang281
12-17-2001 12:22 PM


Did you know that a full grown giraffe's heart weighs over 24 pounds and pumps 16 gallons a minute? Because the giraffe's heart is much larger than his head, a series of special one-way, back-flow preventer valves are needed in the neck to regulate the flow of blood to the head, especially when the giraffe is bending down to get that much needed drink of water. Without these valves, the immense blood pressure coupled with gravity would make for one nasty headache and other such repercussions. Elastic blood vessels in the giraffe's head allow harboring of enough blood to prevent the giraffe from passing out when bent in this position.
How did this evolve?

This message is a reply to:
 Message 40 by redstang281, posted 12-17-2001 12:22 PM redstang281 has not replied

Replies to this message:
 Message 42 by joz, posted 12-17-2001 1:58 PM redstang281 has not replied
 Message 43 by mark24, posted 12-17-2001 3:01 PM redstang281 has replied

joz
Inactive Member


Message 42 of 70 (851)
12-17-2001 1:58 PM
Reply to: Message 41 by redstang281
12-17-2001 12:25 PM


quote:
Originally posted by redstang281:
Did you know that a full grown giraffe's heart weighs over 24 pounds and pumps 16 gallons a minute? Because the giraffe's heart is much larger than his head, a series of special one-way, back-flow preventer valves are needed in the neck to regulate the flow of blood to the head, especially when the giraffe is bending down to get that much needed drink of water. Without these valves, the immense blood pressure coupled with gravity would make for one nasty headache and other such repercussions. Elastic blood vessels in the giraffe's head allow harboring of enough blood to prevent the giraffe from passing out when bent in this position.
How did this evolve?

Well just a guess but probably gradually, over the period of time that the neck was lengthening, those giraffes that didn't keel over of massive cerebral heamorages every time they bent over were more likely to pass their genes on...
Are you even vaguely familiar with the concept of natural selection?
On another note what the hell has the weight of the heart got to do with it? Surely the power with which it pumps blood is far more relevant.....

This message is a reply to:
 Message 41 by redstang281, posted 12-17-2001 12:25 PM redstang281 has not replied

mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 43 of 70 (857)
12-17-2001 3:01 PM
Reply to: Message 41 by redstang281
12-17-2001 12:25 PM


quote:
Originally posted by redstang281:
Did you know that a full grown giraffe's heart weighs over 24 pounds and pumps 16 gallons a minute? Because the giraffe's heart is much larger than his head, a series of special one-way, back-flow preventer valves are needed in the neck to regulate the flow of blood to the head, especially when the giraffe is bending down to get that much needed drink of water. Without these valves, the immense blood pressure coupled with gravity would make for one nasty headache and other such repercussions. Elastic blood vessels in the giraffe's head allow harboring of enough blood to prevent the giraffe from passing out when bent in this position.
How did this evolve?

A mutation that placed pre-existing venal valve in arteries? Veins/capilleries are elastic anyway, so successive mutations that make the said vessels "more elastic" would do the trick.
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 41 by redstang281, posted 12-17-2001 12:25 PM redstang281 has replied

Replies to this message:
 Message 44 by redstang281, posted 12-18-2001 7:44 AM mark24 has replied

redstang281
Inactive Member


Message 44 of 70 (880)
12-18-2001 7:44 AM
Reply to: Message 43 by mark24
12-17-2001 3:01 PM


quote:
Originally posted by mark24:
A mutation that placed pre-existing venal valve in arteries? Veins/capilleries are elastic anyway, so successive mutations that make the said vessels "more elastic" would do the trick.

Wow, so not only would all that have to occur, but also the giraffe would have to be isolated and we would hope that the giraffe baby could nurse milk off the giraffe for a long enough time to grow to reach the tree branches.
This is why the evolution community has given up on that theory of giraffe evolution and has started a new one.
Meanwhile the creationists still maintain the giraffe was created a giraffe as God designed him as one of the creatures to help maintain plant grow.

This message is a reply to:
 Message 43 by mark24, posted 12-17-2001 3:01 PM mark24 has replied

Replies to this message:
 Message 45 by joz, posted 12-18-2001 7:50 AM redstang281 has replied
 Message 55 by mark24, posted 12-18-2001 10:13 AM redstang281 has not replied

joz
Inactive Member


Message 45 of 70 (881)
12-18-2001 7:50 AM
Reply to: Message 44 by redstang281
12-18-2001 7:44 AM


quote:
Originally posted by redstang281:
Wow, so not only would all that have to occur, but also the giraffe would have to be isolated and we would hope that the giraffe baby could nurse milk off the giraffe for a long enough time to grow to reach the tree branches.
This is why the evolution community has given up on that theory of giraffe evolution and has started a new one.
Meanwhile the creationists still maintain the giraffe was created a giraffe as God designed him as one of the creatures to help maintain plant grow.

Which would be fine if you had any evidence for your explanation other than a 2000 year old religious document......
Oh and I think you meant growth not grow....

This message is a reply to:
 Message 44 by redstang281, posted 12-18-2001 7:44 AM redstang281 has replied

Replies to this message:
 Message 46 by redstang281, posted 12-18-2001 8:01 AM joz has not replied

redstang281
Inactive Member


Message 46 of 70 (884)
12-18-2001 8:01 AM
Reply to: Message 45 by joz
12-18-2001 7:50 AM


quote:
Originally posted by joz:
Which would be fine if you had any evidence for your explanation other than a 2000 year old religious document......
Oh and I think you meant growth not grow....

It's funny the extent people have to go through to try and prove the bible wrong. Their theories change all the time.
Yet this single Book stays the same.

This message is a reply to:
 Message 45 by joz, posted 12-18-2001 7:50 AM joz has not replied

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