Things that produce milk and aren't mammals

[skepticality]

Did you all forget the lowly Soy Bean? It sacrifices its milk for many a bowl of cereal?

 

[Myriad]

Vending machines aren't mammals, yet some produce milk.

Respectfully,
Myriad

 

[JoeTheJuggler]

Nobody mentioned coconuts yet?

I know, I know. . . in the OP he clarified the title by specifying bodily secretions that are used to feed young.

 

[shadron]

Vending machines aren't mammals, yet some produce milk.

Respectfully,
Myriad

Excellent example of parallel evolution.

Dinosaurs and mammals coexisted. The mammals are not descended from the dinosaurs. The birds are.

Yes? And?

 

[learner]

Wow.

But how do you milk them?

With a tsetse bitsy little milk maid?

 

[jasonpatterson]

If you want to stretch what you call milk, you could even consider things like aphids which are used by some ant species as 'cattle.'

Also, as someone else mentioned that among the mammals are the marsupials and the platypus, but I'd like to throw in the other, more often forgotten monotreme (egg laying mammal,) the echidna (spiny anteater.) Poor little critters, most people (outside of Australia/New Zealand) don't even know they exist... As I recall, these don't even have teats, their milk just sort of leaks out of a special patch on their skin. (Could be wrong about the last bit, I don't have time to research echidna lactation at the moment...)

 

[godless dave]

As I recall, these don't even have teats, their milk just sort of leaks out of a special patch on their skin. (Could be wrong about the last bit, I don't have time to research echidna lactation at the moment...)

I think you're right, and I think platypuses secrete milk in a similar way.

 

[arthwollipot]

That's why Shadron said "parallel evolution". Not in the same line.

k.

 

[ImaginalDisc]

Mammary glands are modified sweat glands, which is where milk comes from. I think while some birds can reguritate stuff similar to milk, they don't excrete it through a modified sweat gland.

 

[Audible Click]

So many men are actually admiring the modified sweat glands of women...

 

[Uncayimmy]

So many men are actually admiring the modified sweat glands of women...

Is that why they use saline for implants?

 

[shadron]

So many men are actually admiring the modified sweat glands of women...

Oh, gods. Anther breast thread. Just what we need more of ... I think.

 

[TjW]

Vending machines aren't mammals, yet some produce milk.

Respectfully,
Myriad

And think of how productive Magnesias must be, to fill all those bottles.

 

[neutrino_cannon]

Mammary glands are modified sweat glands, which is wear milk comes from. I think while some birds can reguritate stuff similar to milk, they don't excrete it through a modified sweat gland.

See? Mammal chauvinism of the worst sort! As only mammals have sweat glands, this definition is doubly unfair.

Yes, mammal and bird and insect secretions are all ontologically different, but serve clearly analogous functions.

 

[ImaginalDisc]

See? Mammal chauvinism of the worst sort! As only mammals have sweat glands, this definition is doubly unfair.

Yes, mammal and bird and insect secretions are all ontologically different, but serve clearly analogous functions.

Yes, but the biochemical mechanisms and evolutionary histories are important. A lot of the minutea of taxonomy's really important for understanding how such and such came to be.

Bird anatomy is a mystery to me, but the fact that mammaries are modified sweat glands is supported by such. . .odd facts that there are montromes (all extant montremes I think) who secrete milk into their armpit air.

 

[Mr.D]

Out of curiosity:

Are there any non-mammals that secrete lactose in their "milk?" IIRC Columbidae (pigeon/dove) "crop milk," for example is lactose-free.

How about mammal milk that is lactose free?

 

[jasonpatterson]

Out of curiosity:

Are there any non-mammals that secrete lactose in their "milk?" IIRC Columbidae (pigeon/dove) "crop milk," for example is lactose-free.

How about mammal milk that is lactose free?

Lactose is rare outside of mammals (forsythia flowers apparently are a second natural source.) I wouldn't say that no other animals produce lactose bearing milk, but I would wager that no known non-mammals do.

The amount of lactose varies widely among mammal species. Aquatic mammals in general produce low concentrations of lactose in their milk. Eared seals (otariidae) produce no lactose in their milk (or at least so little that it is unmeasurable.) Humans produce a great deal of lactose in their milk, the highest concentration that I was able to find, actually, at 7.1 g/100 mL. (I can't find the link now that I want to add it...) I don't know whether this is due to the rich diet of the people studied or not. Primates in general had high concentrations of lactose though.

This study compares the concentrations of casein and lactose in 31 species of mammals. Unfortunately my school doesn't subscibe...

 

[Mr.D]

Lactose is rare outside of mammals (forsythia flowers apparently are a second natural source.)

Fascinating. Wikipedia says that some Lepidoptera larvae eat Forsythia. Does that mean those species can (or prefer to?) digest lactose. I had been under the impression that mammals and certain bacteria were the only critters that were able to.

Aquatic mammals in general produce low concentrations of lactose in their milk.

I hope someone with knowledge of evolutionary biology can comment on this with respect to the evolutionary advantages of lactose production for land mammals. Higher energy density than simple glucose? Preferential selection of nonpathogenic gut flora in infant mammals?

 

[davefoc]

The Dayak Fruit Bat is the only known instance of paternal lactation in mammals as the norm.

Interesting.

I wonder why this adaptation isn't more common. I believe some human males lactate, so it seems like the basic equipment for producing milk is close to existing in male mammals and yet almost no males of any mammal species routinely produce milk.

Even in this case, the article suggests that it might be hormones in the diets of the bats that make it possible.

Did lactation start out as female only?

Some animals would seem particularly well placed to benefit from male lactation. In the case of bats swapping infant feeding duties so that one parent could remain behind while the other one hunts might be a really good strategy. Especially fruit bats where hunting can be spread out throughout the night as opposed to insectivores where particular hunting times are much better than others.

 

[ImaginalDisc]

Lactose is rare outside of mammals (forsythia flowers apparently are a second natural source.) I wouldn't say that no other animals produce lactose bearing milk, but I would wager that no known non-mammals do.

The amount of lactose varies widely among mammal species. Aquatic mammals in general produce low concentrations of lactose in their milk. Eared seals (otariidae) produce no lactose in their milk (or at least so little that it is unmeasurable.) Humans produce a great deal of lactose in their milk, the highest concentration that I was able to find, actually, at 7.1 g/100 mL. (I can't find the link now that I want to add it...) I don't know whether this is due to the rich diet of the people studied or not. Primates in general had high concentrations of lactose though.

This study compares the concentrations of casein and lactose in 31 species of mammals. Unfortunately my school doesn't subscibe...

Actually, primates have extremely long birth intervals (cetaceans do too, but the longest average interbirth interval belongs to orangutans not any species of whale) and much of that is long brain development. That makes sense.