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Author Topic:   Genuine Puzzles In Biology?
Asking
Junior Member (Idle past 2990 days)
Posts: 19
Joined: 05-19-2010


Message 16 of 153 (562411)
05-28-2010 1:22 PM
Reply to: Message 8 by New Cat's Eye
05-27-2010 4:45 PM


Re: the green gap
quote:
Plants don't absorb green colored light. There's a gap in the spectrum of light that plants can absorb. Why haven't they closed that gap and become capable of absorbing green light?

I imagine the mutation neccessary in the relevent gene to allow them to utilise green light either hasn't happened or it wasn't beneficial enogh to be selected for.

Edited by Admin, : Fix quote.


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New Cat's Eye
Inactive Member


Message 17 of 153 (562413)
05-28-2010 1:33 PM
Reply to: Message 16 by Asking
05-28-2010 1:22 PM


Re: the green gap
quote:
Plants don't absorb green colored light. There's a gap in the spectrum of light that plants can absorb. Why haven't they closed that gap and become capable of absorbing green light?

I imagine the mutation neccessary in the relevent gene to allow them to utilise green light either hasn't happened or it wasn't beneficial enogh to be selected for.

Well... yeah. But answering the question of why it hasn't evolved by saying that it hasn't evolved isn't really answering the question


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Europa
Member (Idle past 2639 days)
Posts: 68
Joined: 06-05-2010


Message 18 of 153 (563621)
06-06-2010 6:29 AM


Interesting topic.

Three things come to my mind right now.

1. Why do we have 2 kidneys when we can very well live a normal life even with one functioning kidney.

2. Why do we have a liver so big when we can very well live a normal life even with a liver half as big?

3. Why do we have a brain so big? I don't remember how much of the brain we use, but it is a pretty small percent.


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Huntard
Member (Idle past 248 days)
Posts: 2870
From: Limburg, The Netherlands
Joined: 09-02-2008


Message 19 of 153 (563622)
06-06-2010 6:34 AM
Reply to: Message 18 by Europa
06-06-2010 6:29 AM


brain stuff
Europa writes:

3. Why do we have a brain so big? I don't remember how much of the brain we use, but it is a pretty small percent.


This is not true, we use pretty much all of our brain, just not at the same time.

I'll leave the other two for other people to answer.

Oh, and a free tip, use the "peek" button on the bottom right of this post to see how I did that nice little quotebox.


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Taq
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Posts: 7594
Joined: 03-06-2009
Member Rating: 3.4


Message 20 of 153 (563686)
06-06-2010 2:00 PM
Reply to: Message 18 by Europa
06-06-2010 6:29 AM


1. Why do we have 2 kidneys when we can very well live a normal life even with one functioning kidney.

Probably has a lot to do with being a bilaterally symmetrical animal.

2. Why do we have a liver so big when we can very well live a normal life even with a liver half as big?

I would hazard a guess that modern diets differ greatly from the our ancestors' diets. Those diets may have contained a lot of toxins that needed to be filtered out. The liver also stores glycogen which would have been important for hunter/gatherers that experienced a feast-famine type of lifestyle.


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Dr Adequate
Member
Posts: 16055
Joined: 07-20-2006
Member Rating: 3.1


Message 21 of 153 (563734)
06-06-2010 4:43 PM
Reply to: Message 18 by Europa
06-06-2010 6:29 AM


1. Why do we have 2 kidneys when we can very well live a normal life even with one functioning kidney.

Well, there are some complications with live kidney donation (hypertension, proteinuria, preeclampsia). But also donors are warned not to take part in rough sports such as American football and boxing, because they're in deep trouble if something happens to their remaining kidney. Which is OK if you live a sedentary Western lifestyle, but not so good if your lifestyle involves hunting antelope.

2. Why do we have a liver so big when we can very well live a normal life even with a liver half as big?

It's hard to say what would happen in the long term to someone with only half a liver, because if you cut a bit off someone's liver it grows back. So I'm not sure on what basis we could say that you can do without it.

It is also the case that sometimes the liver has more work to do than at others. Yes, half a liver might do for everyday use, but what happens if you're exposed to a lot of toxins? Unlike many other organs, the liver has an emergency function, for which extra capacity is required.

3. Why do we have a brain so big? I don't remember how much of the brain we use, but it is a pretty small percent.

The figure usually given is 10%, but it isn't true, it's just a popular myth. It seems to have originated with an advertisement for one of those firms that sells booklets on how to improve your memory.


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Dr Adequate
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Posts: 16055
Joined: 07-20-2006
Member Rating: 3.1


Message 22 of 153 (563783)
06-06-2010 7:55 PM
Reply to: Message 20 by Taq
06-06-2010 2:00 PM


Probably has a lot to do with being a bilaterally symmetrical animal.

Not on the inside, we're not, and in particular the kidneys aren't quite symmetrically placed --- the left kidney is somewhat higher in the abdomen.


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Dr Adequate
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Posts: 16055
Joined: 07-20-2006
Member Rating: 3.1


Message 23 of 153 (563786)
06-06-2010 8:01 PM
Reply to: Message 15 by caffeine
05-28-2010 6:22 AM


Re: Cervical vertebrae number
Thank you.
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AZPaul3
Member
Posts: 3477
From: Phoenix
Joined: 11-06-2006


Message 24 of 153 (563839)
06-07-2010 1:48 AM
Reply to: Message 8 by New Cat's Eye
05-27-2010 4:45 PM


Re: the green gap
As for the green plant issue I think Corgyps came close to the answer but missed the reality.

Though our Lord, Father/Son/Ghost, may to some seem insensitive because of drowning a whole world of babies and for killing and ordering the massacre of multitudes of babies in various events, he really is quite concerned for our feelings when it comes to the food we eat.

Our Lord, YHWH/Jesus/Spirit, or some combination, made plants reflect green light since if they didn't they would only reflect the black part of the EM spectrum and would look black and aesthetically unappealing. Can you imagine consuming a black cauliflower?

I heard once that our Lord, Yahweh/Esau/Essence, or some combination, made bananas long and round for our consumption convenience (though some may see a sexual overtone to this we have to remember that a famous psychologist, I think Simond Fraud, once said that sometimes a cigar is just a cigar cept this one is yellow and has peels. I didn't even know you could peel a cigar).

By having plants green we are more apt to consume them and keep healthy. Our Lord, Jehovah/Lamb/Apparition, knows what would happen if our tomato sauce and orange juice were black. Yuck. Just ask the Irish about black potatoes. And since cows eat plants they would have black meat! You put it on the grill and would not be able to tell when it was done. That is not healthy.

So along with rainbows, salvation and creation, green plants are a gift from our Lord, Elohim/Hazoos/Casper, or some combination.

Edited by AZPaul3, : could this make FSTDT?


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Minnemooseus
Member
Posts: 3670
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 3.4


Message 25 of 153 (563850)
06-07-2010 3:13 AM
Reply to: Message 8 by New Cat's Eye
05-27-2010 4:45 PM


Why plants are green
http://www.pa.msu.edu/sciencet/ask_st/081496.html

quote:
Plants are green because they have a substance called chlorophyll in them. Understanding why chlorophyll is green requires a little biology, chemistry and physics....

It turns out that eons of evolutionary design have matched the absorbance of chlorophyll to the actual color of the sunlight that reaches the leaves. Sunlight consists of primarily blue and red light mixed together, which are exactly the colors that chlorophyll molecules like to absorb. Light is a form of energy, so the chlorophyll is able to harvest the sunlight with little waste.


The above sort of seems to say that chlorophyll has evolved. That does not seem right.

But regardless - Chlorophyll is important for plant metabolism. Chlorophyll reflects green light. Therefore, plants tend to be green.

Moose


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Dr Jack
Member (Idle past 57 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 26 of 153 (563863)
06-07-2010 5:19 AM
Reply to: Message 25 by Minnemooseus
06-07-2010 3:13 AM


Re: Why plants are green
See here for a spectrum showing incoming light intensity; there's no green gap in it. The 500-600nm range over which chlorophyll fails to absorb light is not matched in the incoming light.
This message is a reply to:
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Taq
Member
Posts: 7594
Joined: 03-06-2009
Member Rating: 3.4


Message 27 of 153 (563969)
06-07-2010 2:06 PM
Reply to: Message 22 by Dr Adequate
06-06-2010 7:55 PM


Not on the inside, we're not, and in particular the kidneys aren't quite symmetrically placed --- the left kidney is somewhat higher in the abdomen.

Yes and no. The circulatory system is very bilateral, and the kidneys can best be described as being part of that system. Inside the peritoneum bilateralism breaks down quite a bit.


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Europa
Member (Idle past 2639 days)
Posts: 68
Joined: 06-05-2010


Message 28 of 153 (564002)
06-07-2010 6:01 PM
Reply to: Message 1 by Dr Adequate
05-27-2010 12:05 PM


Mind and Brain
I tried to post this as a new topic. Because it is sitting idle in the proposed topics category, I thought may be I should post it here.

1. How does thought originate?

2. How do you recall something from your memory?

Probably these two questions are similar. But I think they are different. May be their mechanism of origin is similar.

If you believe in mind body dualism, then, they may have an easy answer. But is the mind different from brain? Or is it a 'metaphor' used to signify the collective out put of the brain?


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Minnemooseus
Member
Posts: 3670
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 3.4


Message 29 of 153 (564006)
06-07-2010 6:11 PM
Reply to: Message 26 by Dr Jack
06-07-2010 5:19 AM


Re: Why plants are green
Mr Jack writes:

See here for a spectrum showing incoming light intensity; there's no green gap in it. The 500-600nm range over which chlorophyll fails to absorb light is not matched in the incoming light.

Yeah - The my quoted material does seem to be pretty bogus. But the essential point is what I said after the quote:

Moose writes:

But regardless - Chlorophyll is important for plant metabolism. Chlorophyll reflects green light. Therefore, plants tend to be green.

What would you expect to find in a better adapted plant? Maybe darker green leaves?

Moose

Edited by Minnemooseus, : Add quote attributes.


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Dr Jack
Member (Idle past 57 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 30 of 153 (564068)
06-08-2010 4:36 AM
Reply to: Message 29 by Minnemooseus
06-07-2010 6:11 PM


Re: Why plants are green
What would you expect to find in a better adapted plant? Maybe darker green leaves?

Either modifications to the chlorophyll pigment or the use of additional pigments to increase the proportion of the spectrum absorbed (as some bacteria do, although even they don't completely close the green gap). The bacteriorhodopsin protein used in photosynthesis by halobacteria (actually Archaea not Bacteria) has an absorption spectrum that is pretty much the inverse of chlorophyll so we know such pigments are possible.


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