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Anyone have an idea?
Originally posted by Monique
I still find it strange though that the enzyme is missing, did we loose it in evolution or did it never exist in eukaryotes?
Originally posted by Monique
And if it never existed, what did the ancestor live on?
Originally posted by Monique
There is the same issue in humans, we also depend on the enzymes of micro-organisms for the digestion of our food.
Originally posted by The Opiner
Cows rely on micro-organisms because, unlike "higher organisms", they can digest cellulose (~plant cell walls) and make it available for the cow's metabolic needs.
Originally posted by Monique
I thought they actually break open a number of the bacteria after which the enzyme leaks into the environment and becomes available for the cow?
Originally posted by Monique
How many genes does the cow have? Is it still not strange it can't efficiently break down cellulose?
It has to depend on lots of chewing, regurgitations, 4 stomachs with bacteria. How is the efficiency of absorbing nutrients with this system? I mean a percentage?
Euhh... how does an organism become an organism with a metabolism? By somehow modifying genes so to make the correct enzyme.Originally posted by iansmith
Also, how would the cow acqire the cellulase enzymes.
I am not certain, but I think the appendix had something to do with it.Only 3000 yrs ago (160 generations) did we start farming animals, we depended largely on plant material, how did we digest it without the help of bacteria?
Where did the cow come from then? Since none (I assume) of the (higher) eukaryotes have cellulase, we would have had to live in symbiosis with bacteria a very very long time. Then why is it that only the cow (and other remants? (deer, antelopes, cattle, sheep, and goats)) have multiple stomachs?Originally posted by FZ+
Perhaps this is an example of co-evolution at work - the cow could have developed with these bacteria in its gut, and thus had little or no selective pressure to adapt its own system. Some other animals "farm" fungi, using them to help digest tough vegetation.
Originally posted by Monique
So you really are not surprised that animals don't have a cellulase enzyme?
Originally posted by Monique
When do you think that humans started eating meat? Evolutionarily very recent at the time that the Cro-Magnon appeared, some 50-35 ky ago. Only 3000 yrs ago (160 generations) did we start farming animals, we depended largely on plant material, how did we digest it without the help of bacteria?
Originally posted by Monique
Why do we carry more bacteria with us than cells in our body? You are really saying they don't help in breaking down food for us?
Originally posted by Monique
Then why is it that only the cow (and other remants? (deer, antelopes, cattle, sheep, and goats)) have multiple stomachs?
You should be surprised, since that will lead you to form hypotheses on why thing are the way they are.Originally posted by iansmith
I am not suprised but if it is not present in any animals than is was probably not required.
Wheeew! That is scientific thinking? First of all, since when are chimps carnivorous? Second: they could have started eating meat occasionally independently from the human line.Chimp eat meat. So our ancestor must of eaten meat when they stated to arise.
Mostly on fats. This is not a good example of where evolution started with the development of an organism that required to get nutrition from another place than the sun.Also, inuit depends on meat only for their survival.
Well, maybe, it is hard to say whether the cave people were eating the leaves or not.Also the plant material that we utilize contain a higher concentration of other sugar than leaf materials. We eat the fruit, the grain and the roots. How much cellulose is present in those parts and what is the ratio digestible sugar to cellulose in those parts? We did not need the enzyme.
I don't believe that, humans carry more bacteria in their mouth than a dog does.Bacteria are only present in your large intestine. Your food is mostly digested at this point.
That is a valid argument, but we could just kill all the bacteria right? For some reason we kept them. How come only the good bacteria live inside of you?You got some on your skin, respiratory track (some people carry so nasty pathogens)and women have then in their reproductive track. It is theorize that in the intestine most bacteria are blocking the binding site for potential pathogens.
Originally posted by Monique
Wheeew! That is scientific thinking? First of all, since when are chimps carnivorous? Second: they could have started eating meat occasionally independently from the human line.
Originally posted by Monique
Mostly on fats. This is not a good example of where evolution started with the development of an organism that required to get nutrition from another place than the sun.
Originally posted by Monique
Well, maybe, it is hard to say whether the cave people were eating the leaves or not.
Originally posted by Monique
I don't believe that, humans carry more bacteria in their mouth than a dog does.
Originally posted by Monique
That is a valid argument, but we could just kill all the bacteria right? For some reason we kept them. How come only the good bacteria live inside of you?
It is not strange that organisms should live in Symbiosis for a long time. Eukaryotes are only a collection of symbiotic/Mutualistic prokaryotes afterall.Originally posted by Monique
Where did the cow come from then? Since none (I assume) of the (higher) eukaryotes have cellulase, we would have had to live in symbiosis with bacteria a very very long time. Then why is it that only the cow (and other remants? (deer, antelopes, cattle, sheep, and goats)) have multiple stomachs?
Originally posted by iansmith
Chimp eat small monkeys and they are good at it. It is not a major source of energy but they do it.
We share a common ancestor and they could of had similar eating habits of the chimp. Also meat eating could of independently arise in human and chimp.I am aware chimps eat their young, but do we do that too? No, so it is unlikely that chimps and humans eat meat for the reason and thus that it was because of an ancestor.
What leads you to believe that Inuits are healthy and had no problems in surviving? What happened in the times of the west-Indies companies sailing the seas, they got all kinds of diseases due to lacking vitamins etc because they didn't have fresh fruit and vegetables. Again, these examples of Inuits and chimps are evolutionary too recent!Could a vegeterian adapted human survive so well in this enviroment. It does tell us how the organism started but it give some clues.
Ok, fine. So let's forget about our branch. Let's think about the other branch that developed into animals: the first heterotroph.If our ancestor were eating signifcantly large quantity of leaves would we keep the habit. What is the diet of "primitve" tribes? How much leaf component are they eating in their diet. I can give us significant inside to some of the eating habits of our ancestor. Chimp do have 20% of their diet compose of leaf.
Yes, they die in the stomach and what happens to the enzymes that get released? They are released to the environment and thus enrich our enzymatic capacity (if the enzyme still has activity at low pH).I long does our food stay in our mouth. It is not signficantfor bacteria to digest the food. Any way they will probably die in your stomach and what is left will not have a major impact on the digestion of the food.
What happens to a baby when it first starts taking food? It can't digest it. Why? Untill after a while the bowel get populated with bacteria and things stabilize. Bacteria in our bowel are attacked by enzymes too and brake open and release their cytoplasms, it is very easy to state that this doesn't help us. Do you have a publication to back yourself up?We do not only have good bacteria in inside us. Some peope carry virulent strain of Neisseria meningitis and Staphylococcus aureus in the nasal cavity, some carry Salmonella. Most species of bacteria inside will not harm us or will not be beneficial. We do not kill the bacteria inhabiting us because they adapted to us. Our insides is an excellent environment for them.
Originally posted by Monique
I am aware chimps eat their young, but do we do that too? No, so it is unlikely that chimps and humans eat meat for the reason and thus that it was because of an ancestor.
Originally posted by Monique
What leads you to believe that Inuits are healthy and had no problems in surviving? What happened in the times of the west-Indies companies sailing the seas, they got all kinds of diseases due to lacking vitamins etc because they didn't have fresh fruit and vegetables. Again, these examples of Inuits and chimps are evolutionary too recent!
Originally posted by Monique
Ok, fine. So let's forget about our branch. Let's think about the other branch that developed into animals: the first heterotroph.
Originally posted by Monique
Yes, they die in the stomach and what happens to the enzymes that get released? They are released to the environment and thus enrich our enzymatic capacity (if the enzyme still has activity at low pH).
Originally posted by Monique
What happens to a baby when it first starts taking food? It can't digest it. Why? Untill after a while the bowel get populated with bacteria and things stabilize.
Originally posted by Monique
Bacteria in our bowel are attacked by enzymes too and brake open and release their cytoplasms, it is very easy to state that this doesn't help us. Do you have a publication to back yourself up?
You are saying they were healthy and at the same time they suffered from disease? The only reason Inuits were able to survive was that their diet consisted of fats from the seals, which contained necessary nutrients.Originally posted by iansmith
Your example is bad. Inuit were healthy. They are very well adapted to their enviroment. They did suffer from the same disease as the European that travel to the north.
I am thinking about a whole range of enzymes in this case which might be usefull for us.The enzyme is probably not active at pH 2.0 and it probably get degraded in the stomach.
Ok, just understand that there are no bacteria in breast milk right?Within hours the baby get kisses and is feed by his mother.
Good argument.If bacteria had a significant digestive power ther would be not lactose or any sugar intolerance. Bacteria feed on these sugar for them self not for our benefit.
I don't, I look at the situation and postulate an hypothesis that an interaction is taking place, while you argued that nothing is going on which contradicts the observation. Btw, I have the example of the cow backing me up that bacteria are important in digestion.The only references I have are my notes from my microbiology class. Do you have any reference to back your self up.
Originally posted by Monique
You are saying they were healthy and at the same time they suffered from disease?
I am thinking about a whole range of enzymes in this case which might be usefull for us.
Ok, just understand that there are no bacteria in breast milk right?
Btw, I have the example of the cow backing me up that bacteria are important in digestion.
Originally posted by Monique
But does that have to do with the microflora?
Originally posted by Monique
How does a baby know which of the microflora is good and which is bad? I wouldn't want to desensitize against bad ones..
Originally posted by Monique
I am not sure what the mode of entry of the allergen is, inhalation perhaps?