So why do men have nipples?

[juvenissun]

How so? Wisdom teeth serve no purpose in the human mouth, except to crowd an already over-crowded mouth. In our simian cousins, the mouth is big enough to comfortably accommodate wisdom teeth. Our faces, however, have evolved to be flatter than theirs, resulting in an over-cramped mouth.

I am drifting away from the OP. But ...

So, why do we "need" fewer teeth? What was the pressure to drive that? Instead, I think we should have MORE TEETH (and a bigger mouth, like the dinos). Did Neanderthals (or even the Lucy) have more teeth than us?

 

[Naraoia]

We began to eat processed food...

 

[juvenissun]

Juv- since you think you can state as a "fact" that "evolution is a fairy story", that you know more than anyone else ("highest level of education that it is possible for a human being to have"), and, since amount of evidence on earth could ever get you to grasp that you are wrong about anything, why do you even bother to ask questions?

You dont accept or believe any answer you ever get. Isnt it a bit dishonest of you to even ask when it is predetermined that you wont accept any answer except goddidit?

The purpose for me to give question is to get YOU to think. In fact, I give you a question, the major work then has already been done. Your answer does not really matter. Since you started to post here, how many meaningful questions have you ever asked? As far as I can tell, most people here are simply following the the thought I lead.

Do you know what is the job for those who sit in a Ph.D. committee? Yes, they simply asked questions that they have no answer to. As a candidate, if you gave a good answer, they may ignore it, and try another one. If you gave a bad answer, then you are caught.

So far, Wiccan_Child's answers are not bad. Of course, a main reason is that I am not a biologist and I am pretty bad in biology.

 

[juvenissun]

We began to eat processed food...

Do you think we can teach a monkey to raise fire and to cook its food? If so, would it eventually refused (or preferred not) to eat natural food? It should not be a hard experiment to do.

 

[Naraoia]

Of course, a main reason is that I am not a biologist and I am pretty bad in biology.

Then you should view yourself as a student and not an examiner here, don't you think?

 

[Wiccan_Child]

I am drifting away from the OP. But ...

So, why do we "need" fewer teeth?

Because our mouths can't fit them all in: if our mouths get smaller, but our teeth remain unchanged, that leads to crowing. And with crowing comes a whole host of dental problems, bleeding, and infections.

What was the pressure to drive that?

What was the pressure to shrink our mouths? It's due to a change in diet: big mouths with numerous large, flat teeth is very good at grinding down plants. As our diet changed, natural selection selected against such large mouths. Shrinking our mouths is a relatively easy thing to do (from an evolutionary point of view), but changing the number of teeth is not.

Maybe in the future we'll lose wisdom teeth altogether, but for the time being, they're vestiges of a time when our diet was quite different.

Instead, I think we should have MORE TEETH (and a bigger mouth, like the dinos).

How so? What benefit would there be in having more teeth in an already over-crowded mouth?

Did Neanderthals (or even the Lucy) have more teeth than us?

I'd wager they had the same number as us, but I honestly don't know.

 

[Wiccan_Child]

The purpose for me to give question is to get YOU to think. In fact, I give you a question, the major work then has already been done. Your answer does not really matter. Since you started to post here, how many meaningful questions have you ever asked? As far as I can tell, most people here are simply following the the thought I lead.

Do you know what is the job for those who sit in a Ph.D. committee? Yes, they simply asked questions that they have no answer to. As a candidate, if you gave a good answer, they may ignore it, and try another one. If you gave a bad answer, then you are caught.

So far, Wiccan_Child's answers are not bad. Of course, a main reason is that I am not a biologist and I am pretty bad in biology.

Aww shucks .

Asking questions is never a bad thing. Who knows, maybe you'll ask us something that really stumps us!

 

[Naraoia]

Do you think we can teach a monkey to raise fire and to cook its food? If so, would it eventually refused (or preferred not) to eat natural food? It should not be a hard experiment to do.

I don't know if they prefer cooked food, but some of them did figure out how to wash it (though I suspect that's more about seasoning than cleaning, as the washing was done in the sea).

Why is that important?

 

[juvenissun]

However, organs cost resources to build and maintain. Reproduction also costs resources: making sex cells, finding mates, fighting rivals and whatnot. An animal can only get so much food, which doesn't exist in infinite quantities.

So, if you have a big expensive organ that you don't use for anything, your reproductive success is going to suffer compared to those who have a smaller version or none of the useless organ at all. In these cases, there IS a selective pressure on the useless organs - in the direction of making them shrink.

The ones that can stay are the ones that confer no particular disadvantage. The ones that will definitely stay are the ones that are so heavily integrated into the developmental program that you can't remove them without upsetting something very important.

No.

Yes, monotremes do it. The nipple doesn't produce milk, it just makes it easier for the baby to suck it.

Because they rarely have more than two offspring at a time. They rarely have even two.

I think some people are born with multiple nipples, though. *searches* Yes, it seems it's quite common, although the additional nipples are usually not well developed. Again, a remnant of a past when our ancestors were more conventional mammals with larger litters.

I don't know if there's a specific advantage to having paired nipples (other than being helpful for mothers of twins), but having just one nipple would require symmetry breaking, and my guess is that that's not the easiest thing to evolve. (If anyone has more than a guess, though, I wouldn't mind some education)

It had mammary glands, it probably didn't have nipples. The two are not the same thing.

As I said, the most obvious reason I can think of is that nipples make suckling more efficient. A baby mammal sucking a nipple can probably (I haven't seen actual measurements) get milk faster than one licking milk off mum's hair, and I'm pretty sure that less milk goes to waste if there's a nipple. I think it's a reasonable assumption that that translates into better growth for the young at a lower price for the mother.

Not necessarily.

First, parental care in general has a number of advantages:

(1) It increases the chance that any particular offspring will survive. It allows for fewer offspring overall (imagine having to care for the millions of eggs some fish lay!), but most of the offspring of non-caring species die very young, so it balances out.

(2) It lets the young grow faster: while the offspring of non-caring species must spend a lot of time and energy finding food, the young of many caring species don't have to do anything but sit in one place and eat what their parents bring (in this respect, many insects count as "caring" species, since they lay eggs in the middle of a huge, often protected, food supply). And grow. Faster growth is good for more than one reason: first, it gets you out of the "everyone eats you" size range more quickly, and second, it means you can mature and reproduce earlier.

Milk in particular is good because again, a food source tailored to your needs allows better growth than a food source that doesn't have an ideal composition. Plus, milk is a great way of immunising a newborn against many diseases while its own, previously sheltered, immune system is still learning to recognise pathogens.

So no, milk isn't "unfavorable to evolutional process". It's just one of several alternative strategies ensuring that at least a few of your genes get into the new generation, and seeing as there are still a few thousand mammalian species all over the globe a couple hundred million years (or more) after the invention of milk, it clearly can't be that bad.

Thanks for the answers.

So, the emergence of mammal from reptile (?) represented many fundamental biological changes. What was the pressure that made all these changes happen at almost at the same time? For example, the reduction on the number of babies SHOULD take place together with the appearance of mammary gland. It doesn't make sense if these two features evolved in a time sequence. In the dinosaur era (Cretaceous?), the way dino lived (fittest) was the correct way life should live at that time/environment. If so, why would the mammal appear in against the best conditions environment can offer at that time? This was a fundamental change and the pressure should be tremendous.

 

[juvenissun]

I don't know if they prefer cooked food, but some of them did figure out how to wash it (though I suspect that's more about seasoning than cleaning, as the washing was done in the sea).

Why is that important?

Do you think the taste of monkey is different from ours? I don't think so. Even my dog likes cooked food (no salt, no flavoring) and soup.

So, if they know how, they will process food. That means our ability of processing food (eat raw meat --> eat cooked food, by fire) is not evolutional.

I predict the result: If we teach monkeys to cook food, they will ask for cooked food every time. The only problem for them to cook is to raise fire. Otherwise, they will cook.

 

[juvenissun]

Then you should view yourself as a student and not an examiner here, don't you think?

I only ask questions. Am I a student or a examiner?

 

[Wiccan_Child]

Thanks for the answers.

So, the emergence of mammal from reptile (?) represented many fundamental biological changes. What was the pressure that made all these changes happen at almost at the same time?

The extinction of 99% of all life on Earth opened up vast new ecologies for the survivors to occupy. A large variety of traits which had no benefit suddenly became very beneficial. Only those who changed rapidly could survive the environment that changed even faster. This lead to numerous novel traits in isolated groups. One such group evolved hair, sweat glands, middle-ear bones, etc, and was the ancestor of modern mammals.

At least, that's my take on it.

For example, the reduction on the number of babies SHOULD take place together with the appearance of mammary gland. It doesn't make sense if these two features evolved in a time sequence. In the dinosaur era (Cretaceous?), the way dino lived (fittest) was the correct way life should live at that time/environment.

Dinosaurs were an extremely wide and varied group: there was no one way in which they lived, and their ways wouldn't easily cross-over to other species.

For instance, the ways of the snake are 'perfectly suited' for snakes, but not for mammals. What good does a dog have basking in the desert sun? The snake maintains an optimal internal temperature, but the dog just overheats and dies.

 

[Hespera]

Juv sez:

Do you think the taste of monkey is different from ours? I don't think so. Even my dog likes cooked food (no salt, no flavoring) and soup.

So, if they know how, they will process food. That means our ability of processing food (eat raw meat --> eat cooked food, by fire) is not evolutional.

I predict the result: If we teach monkeys to cook food, they will ask for cooked food every time. The only problem for them to cook is to raise fire. Otherwise, they will cook. QUOTE/////

Hespera sez:

The taste of monkey. Only one way to find out. You try it, i dont want to taste monkey.

As for dogs preferring cooked food, I suppose that is so, depending on the dog and what was cooked. Dogs like to eat different things, maybe you cant generalize. i have a friend whose dog will eat live fish out of a bucket of water. I expect some other dogs would starve first.

A person could perhaps teach a zoo monkey to cook. and provide it with a steady heat source to use. You'd have to teach the boss monkey tho, or the others wont learn.

(based on a Tokyo zoo observation, that they put a food machine in the enclosure. First they taught a jr. monkey to use it, but the others wont learn from him, just stole from him. Then they taught the alpha male to use it, and the others crowded around. As soon as he was done they imitated his moves, and soon they all could push the right buttons and get their food)

 

[Naraoia]

So, the emergence of mammal from reptile (?) represented many fundamental biological changes.

Well, quite a few of them, though I'm not sure if we can call most of them "fundamental".

What was the pressure that made all these changes happen at almost at the same time?

None, because they didn't all happen at the same time. This transition dragged on from the end of the Carboniferous (300ish Mya) to... somewhere during the Jurassic (between 200 and 144 Mya), I think, although I think milk arose quite late in the process.

For example, the reduction on the number of babies SHOULD take place together with the appearance of mammary gland. It doesn't make sense if these two features evolved in a time sequence.

Really? Why don't birds have mammary glands, then? Or, since mammary glands are modified sweat glands, and birds don't have sweat glands, why don't they all secrete crop milk the way pigeons do?

The reduction in the number of babies should take place together with an increased investment in them, and any active feeding the young is increased investment.

(Producing larger eggs is also an investment, but reptiles already do that - which is why they don't lay thousands of eggs like frogs do).

In the dinosaur era (Cretaceous?), the way dino lived (fittest) was the correct way life should live at that time/environment.

There is no "the" correct way. There are many "correct" strategies in any given environment, and what your best strategy is depends on what you can do as well as what others around you do.

I thought we've been through this already?

If so, why would the mammal appear in against the best conditions environment can offer at that time? This was a fundamental change and the pressure should be tremendous.

I'm not sure what you're asking here, but mammals, or very mammal-like things (depending on your definition of a mammal ) were around before the dinosaurs really took off, and mammals were quite successful as smallish animals during the whole age of dinosaurs. As for the pressure, I think endothermy (which they had probably acquired by the time dinosaurs came about) had a lot to do with the extent of parental care that mammals developed (although I'd guess that some degree of parental care is a prerequisite to full-blown endothermy rather than a consequence)

Being a baby animal that has to hunt in order to grow is difficult enough, but being a baby animal that has to hunt in order to grow and needs ten times the food that a similar-sized ectotherm does and may be too small to keep warm on its own... well, there's a selective pressure for mum to cuddle and feed her hatchlings.

the taste of monkey is different from ours? I don't think so. Even my dog likes cooked food (no salt, no flavoring) and soup.

So, if they know how, they will process food. That means our ability of processing food (eat raw meat --> eat cooked food, by fire) is not evolutional.

Um, why does it mean that? It's the same as saying that because monkeys are hairy, our scarce hair couldn't have evolved. Given that the very essence of evolution is change, that reasoning quite simply doesn't make sense.

I predict the result: If we teach monkeys to cook food, they will ask for cooked food every time. The only problem for them to cook is to raise fire. Otherwise, they will cook.

See, I'm pretty sure that you could teach at least some of them to make fire. Seeing as Kanzi the bonobo learnt to make very good chipped stone tools, I don't think fire should be an impossibility.

Now that you mention that, I wonder what would happen if someone taught those potato-washing monkeys how to make fire and roast those potatoes, and checked back a few decades later...

I only ask questions. Am I a student or a examiner?

You compared yourself to an examiner, if memory serves.

 

[juvenissun]

Well, quite a few of them, though I'm not sure if we can call most of them "fundamental".

None, because they didn't all happen at the same time. This transition dragged on from the end of the Carboniferous (300ish Mya) to... somewhere during the Jurassic (between 200 and 144 Mya), I think, although I think milk arose quite late in the process.

Really? Why don't birds have mammary glands, then? Or, since mammary glands are modified sweat glands, and birds don't have sweat glands, why don't they all secrete crop milk the way pigeons do?

The reduction in the number of babies should take place together with an increased investment in them, and any active feeding the young is increased investment.

(Producing larger eggs is also an investment, but reptiles already do that - which is why they don't lay thousands of eggs like frogs do).

There is no "the" correct way. There are many "correct" strategies in any given environment, and what your best strategy is depends on what you can do as well as what others around you do.

I thought we've been through this already?

I'm not sure what you're asking here, but mammals, or very mammal-like things (depending on your definition of a mammal ) were around before the dinosaurs really took off, and mammals were quite successful as smallish animals during the whole age of dinosaurs. As for the pressure, I think endothermy (which they had probably acquired by the time dinosaurs came about) had a lot to do with the extent of parental care that mammals developed (although I'd guess that some degree of parental care is a prerequisite to full-blown endothermy rather than a consequence)

Being a baby animal that has to hunt in order to grow is difficult enough, but being a baby animal that has to hunt in order to grow and needs ten times the food that a similar-sized ectotherm does and may be too small to keep warm on its own... well, there's a selective pressure for mum to cuddle and feed her hatchlings.

Um, why does it mean that? It's the same as saying that because monkeys are hairy, our scarce hair couldn't have evolved. Given that the very essence of evolution is change, that reasoning quite simply doesn't make sense.

See, I'm pretty sure that you could teach at least some of them to make fire. Seeing as Kanzi the bonobo learnt to make very good chipped stone tools, I don't think fire should be an impossibility.

Now that you mention that, I wonder what would happen if someone taught those potato-washing monkeys how to make fire and roast those potatoes, and checked back a few decades later...

You compared yourself to an examiner, if memory serves.

Thanks for the reply. Too bad I don't have time to argue (the lack of knowledge demands a lot of time to think). I always wonder why couldn't ape learn what we did. It is a major barrier for me to believe the evolution of human. Give ape another few million of years, would they learn how to make fire? I don't think so.

It is fine for you to model evolution on animals. But, NEVER think that you evolved from ape. You don't.

 

[Hespera]

If there were to be a heaven, no doubt it would only be right for there to be some sort of reception line. Your grandparents or parents... your great grandparents, great great great great etc. back through the generations.

It would be very interesting, what you would think of them, and what they would think of you. People less and less like you, in life experience, values, everything.

Somewhere further back in the line you'd be meeting people who really didnt look that much like you at all. Heavy brow ridge, more protruding jaw..... at some point this business of not having "ape" ancestors (especially as people are apes) would start to come into focus.

Here are your ancestors, waiting in line to meet you and see what the family tree has become and what do you do...denounce them? >I<, you say, have a BOOK that says you are not my ancestors; get ye hence?

Or maybe "NEVER think that I am descended from the likes of YOU!" Try it! It will be funny.

 

[Gracchus]

Of course, a main reason is that I am not a biologist and I am pretty bad in biology.

Would you believe we've noticed?

 

[Vehementi Dominus]

Do you think the taste of monkey is different from ours? I don't think so. Even my dog likes cooked food (no salt, no flavoring) and soup.

So, if they know how, they will process food. That means our ability of processing food (eat raw meat --> eat cooked food, by fire) is not evolutional.

I predict the result: If we teach monkeys to cook food, they will ask for cooked food every time. The only problem for them to cook is to raise fire. Otherwise, they will cook.

Throughout our evolutionary history, we were, more often than not, scavengers. Eating whatever we could find, poking things, picking things, whatever, if it looked edible, we'd eat it. We had to be like that to survive, we were too small to hunt anything other than small animals and insects, and even then, without tools. A burnt corpse left out after a natural fire would've been like a banquet. Nature's barbeque.

We learned, through scavenging, that being inquisitive pays off. The alpha male of ancient species such as austrolapithicus would've been chosen through being able to find food, not just their physical prowess. It's this inquisitive nature that has helped us survive, and become the humans we are today.

Ultimately, we didn't invent fire, we found it and used it to our advantage.

 

[Naraoia]

Thanks for the reply. Too bad I don't have time to argue (the lack of knowledge demands a lot of time to think).

From my experience in thinking, if you lack knowledge, thinking in a meaningful way is very hard. Maybe you'd be better off gaining knowledge before you think too much

I always wonder why couldn't ape learn what we did. It is a major barrier for me to believe the evolution of human.

Why can't all birds remember the exact location of thousands of food items they'd hidden? Does that mean that the incredible spatial memory of scrub jays couldn't have evolved? Or does such reasoning only apply to humans? Why?

Give ape another few million of years, would they learn how to make fire? I don't think so.

Again, you seem sure about this without having the slightest clue.

I don't think we know what caused us to evolve our intellectual abilities in the first place, which means we don't really have a way of predicting whether chimps or orangs or gorillas would follow a similar trajectory if left alone. Evolution isn't just a matter of time.

It is fine for you to model evolution on animals. But, NEVER think that you evolved from ape.

Why?

(No, don't come with the Bible. If you bring it up, please give me a reason why I should accept what [you think] it says. "Bible says so" is not a reason. If you can't do that, don't bother mentioning the Bible.)

You don't.

Four out of five apes don't want to be related to you either

 

[Hespera]

From my experience in thinking, if you lack knowledge, thinking in a meaningful way is very hard. Maybe you'd be better off gaining knowledge before you think too much
me.

r

For some of our posters, "thinking" consists of wondering how Procrustes would take the facts and the bible, then stretch, chop and twist until the two fit.