Half orcs are real

[Jeremy Ackerman-Yost]

Yes, but the males usually aren't. And even if they were - these crosses have not, to my knowledge, ever been observed in the wild, even in the times when the species shared territory.

True. But felines and hominids are a rather different ballgame.

Hominids will mate with a rock if it's shaped roughly the right way. So will lots of other primates.

It is my understanding that most of that "habitual" crossing is human induced, though, and doesn't happen to noticeable extents if you leave the populations sitting next to each other in the wild. Human-forced crossbreeding doesn't count.

Not remotely true. Many types of plants do all kinds of ridiculous genetic mumbo jumbo. In some cases, you might call it genetic gumbo. But they're amateurs. Multiploidy is a kid's game. Bacteria, on the other hand, are masters. They habitually trade genes between two cells that have almost no similarities at all besides their choice of habitat. Oomycetes and fungi are a minefield. They're playing every shell game and con you can imagine with their genes and chromosomes, not to mention their morphology and life cycles. As soon as genetic testing became available, we found out that we had no idea what the heck we were talking about with most of them. Same genetic species with multiple different morphologies. Identical morphologies with entirely different genomes. Interbreeding, gene transfer, and half a dozen other oddities taking place under our noses every day.

But who would know? Some scientists are still debating whether we need 7 or 8 Kingdoms of Life to account for everything we've learned, but most schools are still teaching 5 or less. I've bumped into high schools that are teaching four. I don't think that was ever an accepted breakdown in the scientific community, but apparently someone printed some text books that way at some point.

Animals stay apart long enough to develop a different color of fur, and they might choose to shun each other for mating, even though they are completely viable together. Some plants/fungi/etc stay apart for millions of years and mate the instant they are brought back together.... even though in the intervening eons they've developed typical physical characteristics that look nothing at all like each other during at least one phase of their life cycle. Spores and pollen simply don't tend to be picky based on something as superficial as color.

Actually, despite a handful of exceptions, the rule still holds up well. No reason to invoke a conspiracy to dumb down the science.

I was being somewhat facetious with the "conspiracy" stuff. It comes down more to laziness than anything like that. But... the fact that multiple intelligent men in this very thread have no idea how our species concept is full of holes and fallacies shows that we're really not getting our education on.

It really, really doesn't hold for anything that isn't an animal. Exceptions to the species concept are relatively rare among animals. For every other form of life, strict adherence to the the species concept is the exception.

But, if you're not a biologist... you'll never notice. In terms of genetic bouillabaisses or chromosomic two-steps animals mostly keep it simple, and we pay a lot of attention to animals. But the trees in your backyard are likely doing all kinds of polygenomic tangos without you ever noticing. When it comes to crop and human pathogens, it might be having an incalculable impact on your life, but it's way below the level of your awareness.

Now, considering we know about a bare fraction of the animals on the planet, and we've already found a couple dozen exceptions to the strict species concept, and non-animals thumb their noses at it constantly..... why are we surprised when we find another blip on that radar?

Because we convinced ourselves that we had discovered a RULE. When we had actually found a weak set of guiding principles.

Dethroning a RULE is hard. Tweaking weak guiding principles is easy. But RULES are simple and sexy. People like them. Weak guiding principles are complicated. No one likes them.

There are cultural issues that resist this as well, but I don't know how to talk about them within forum rules.

 

[Raven Crowking]

At least one Polar/Grizzly Bear cross has been reported in Canada, on the basis of DNA from bagged specimen.


RC

 

[Umbran]

Hominids will mate with a rock if it's shaped roughly the right way. So will lots of other primates.

The only other primates I know who behave in similar ways are bonobos. If you've got other information, I'd be interested in hearing of it. Especially about observations in the wild - captivity induces some strange behavior changes.

Not remotely true. Many types of plants do all kinds of ridiculous genetic mumbo jumbo. In some cases, you might call it genetic gumbo. But they're amateurs. Multiploidy is a kid's game.

Yes. "Multiploid" means "having multiple copies of a chromosome". Humans are multiploid - human gametes are "haploid", and have only one copy of each chromosome. Multiploidy has nothing at all to do with cross-breeding with other species.

Bacteria, on the other hand, are masters. They habitually trade genes between two cells that have almost no similarities at all besides their choice of habitat.

True. But then, they aren't undergoing sexual reproduction, either. That's the only genetic mixing they get. The real question is how much genetic change that actually represents for the entity. How many new genes does an individual bacterium pick up in its lifetime, and pass on to its daughter cells at division? How many differences does a puppy have from a parent dog?

Oomycetes and fungi are a minefield. They're playing every shell game and con you can imagine with their genes and chromosomes, not to mention their morphology and life cycles.

While neat and interesting, the play they have with their morphology and life cycles is not relevant when discussing whether they cross-breed with other species.

But who would know? Some scientists are still debating whether we need 7 or 8 Kingdoms of Life to account for everything we've learned, but most schools are still teaching 5 or less.

Not to say you are incorrect in your point, but the support here isn't so good. "Some scientists" also still think that cold fusion works.

 

[Jeremy Ackerman-Yost]

I was running fast over the top, as befits this not being a science forum, but if you want, I'll go into some of these in detail.

There are primates in the wild who masturbate vigorously by rubbing themselves on trees. There are Old World monkeys who include sex in their social grooming, as part of the group bonding experience. And this is just including the stuff I've seen in BBC nature shows, to say nothing of the wacky crap primatologists I've worked with have told me. I know a dude who spent some time in Madagascar observing lemurs, and even those little punks are pretty frisky.

Technically, primates don't have the lock on sex as a social tool, either. Dolphins engage in sex as social bonding. Canines engage in sex as dominance display. Some birds do social bonding sex as well.


As for plants.... Polyploidy in this context is referring to having various numbers of copies of the same set of chromosomes, and producing viable individuals that way.

Most animals are diploid for most of their life cycle, with haploid gametes or occasional haploid life cycles. You need one full set of chromosomes from your mom and one from your dad to be a functional vertebrate, for example. Haploid vertebrates don't work. Vertebrates with more than 2 sets (triploid and up) don't work. You need to be diploid, end of story (with some noise there for extra individual chromosomes, but you'll note those always come with problems)

Some plants can have 3, 4, 5, etc complete sets of chromosomes (I've heard of as many as 12), but not necessarily the same number of sets between individuals. Sometimes a plant with 4 sets behaves very differently from a plant with 3, to the point where we call them a different species. But they interbreed just fine. Or sometimes they all behave exactly the same as long as they have 2 sets or more.

Some plants that are actually quite distinct, genomically, can reproduce, so you end up with, say, 3 copies of one set of chromosomes and 1 or 2 of a different one. The offspring are totally viable, and when they make gametes, those gametes might end up with one set of chromosomes, from one parent species or the other.

This violates the strict species concept 6 ways from Sunday.


On the bacteria thing... if I can pick up single genes or strips of genes from any other bacterium I bump into that has the right signaling molecules on its membrane, regardless of species... that's a pretty significant divergence from the strict species concept. Genetic recombination between species wasn't even on the table.


On fungi/protista/chromista/whatever-the-heck-the-current-divisions-are... There are morphologically and genetically distinct fungi found in, for example, Europe and New Zealand, that turn out to be 100% capable of reproducing when introduced to each other. There are bacteria-like gene exchanges between separate species. There are critters of the exact same species who refuse to reproduce with each other, and then turn around are reproduce with something else entirely. Some fungi that we consider one species are actually several species of haploid cells growing in a mixed-species colony. Their diploid stage might be some other "species" entirely. And then sometimes two haploid fungi of different species manage to randomly create a diploid pairing that works.

Those are fun. They're like a dog, a rat, a chimp, a human, and a narwhal dropping some gametes together in a spot such that they would clump together and grow into an oak tree. That oak tree would grow up and produce seeds. Those seeds would then grow into new dogs, rats, chimps, humans, narwhals, and every once in a while a unicorn and a hippogryph, but only paired like that, except on alternate Tuesdays, when they produce dragons and dung beetles.

You don't think that might be a bit outside the species concept box that we're all taught in high school?

 

[I'm A Banana]

I can't give you XP right now, Canis, but I am learning so much.

I knew speciation was a finnicky beast, and that the homo genus is potentially filled to the brim with "ah, but this guy was just kind of short," and "well, maybe it was a family of guys with big jaws," and "I found the missing link! No, I did!" but I didn't know how genetically haphazard non-animals are.

The Flying Spaghetti Monster truly created the world in his noodly image: kind of a mash of fluids and sugars all tangled together.

 

[Umbran]

There are primates in the wild who masturbate vigorously by rubbing themselves on trees.

Yes, but unless you're going to claim that the monkey-puzzle tree is a result of such, I don't see how it bears on the discussion. Masturbation behavior is not "mating".

There are Old World monkeys who include sex in their social grooming, as part of the group bonding experience.

Their group is all the same species, though. How many orgies primates have isn't the question - how often they mate outside their own species is the question.

This violates the strict species concept 6 ways from Sunday.

I'd argue that it does not, and that geneticists would agree with me. The whole notion of polyploidy admits that we are talking about the number of copies of the same basic chromosome, coming from another of the same basic type of living thing. In terms of talking about "species", it doesn't matter how many copies of chromosomes a maple tree has if all those chromosomes all come from other maple trees!

On the bacteria thing... if I can pick up single genes or strips of genes from any other bacterium I bump into that has the right signaling molecules on its membrane, regardless of species... that's a pretty significant divergence from the strict species concept. Genetic recombination between species wasn't even on the table.

Yes, but this is the only place where you've actually talked about natural trading of genes across species lines.

I pointed out before, though that the fact that a bacterium can pick up some genes from other species is not necessarily all that big a deal, if those genes have little impact on the beastie, and don't change it's nature overmuch. I asked a question that seemed to have gotten lost - how much genetic difference is there between a parent bacterium and it's daughters? How much genetic difference is there between a puppy and its dam?

Yeasts can play the trick you're talking about. But yeast has pretty much been yeast since at least the dawn of human civilization.

You don't think that might be a bit outside the species concept box that we're all taught in high school?

Not too terribly, no. What you've demonstrated is that creatures with only small amounts of cellular differentiation can sometimes experiment a little with their genetics. This by no means blows the entire concept out of species out of the water - it merely indicates we have to be a little careful in discussing it sometimes.

This may have less to do with the definition of "species" and more to do with the functions of genes in life that doesn't differentiate it's cells so much.

You've missed a few examples I can think of that do actually make us think a bit about what qualifies "species". I'll see if I can get to jotting those down later today.

 

[Desdichado]

But who would know? Some scientists are still debating whether we need 7 or 8 Kingdoms of Life to account for everything we've learned, but most schools are still teaching 5 or less.

Probably quite a few more if we also account for all the groups that popped up in the Cambrian and Precambrian.

I was being somewhat facetious with the "conspiracy" stuff. It comes down more to laziness than anything like that. But... the fact that multiple intelligent men in this very thread have no idea how our species concept is full of holes and fallacies shows that we're really not getting our education on.

Or... we're talking about it at high level because there's no need to get into the detail, really. Also, see below.

It really, really doesn't hold for anything that isn't an animal. Exceptions to the species concept are relatively rare among animals. For every other form of life, strict adherence to the the species concept is the exception.

The discussion isn't about speciation in general, it's about a specific example and question of speciation (vs. sub-speciation, if that's a word) in one animal group. So no, we're not (well, I'm not, anyway) uneducated about the issues, it's just that many of them don't apply to the discussion we're having right now.

Because we convinced ourselves that we had discovered a RULE. When we had actually found a weak set of guiding principles.

Dethroning a RULE is hard. Tweaking weak guiding principles is easy. But RULES are simple and sexy. People like them. Weak guiding principles are complicated. No one likes them.

There are cultural issues that resist this as well, but I don't know how to talk about them within forum rules.

I think you're projecting a bit. I knew all along that the boundary between a species, a subspecies, and merely an isolated population within a species is a bit fuzzy, but many of the details around that fuzziness weren't all that relevant to the discussion. :shrug:

At least one Polar/Grizzly Bear cross has been reported in Canada, on the basis of DNA from bagged specimen.

As they say, the exception proves the rule. One sample doesn't a species barrier break down.

That said, polar bears are descended from grizzly bears in the relatively recent past, so they're probably still viable. But, generally speaking, they don't interbreed in the wild.

Technically, primates don't have the lock on sex as a social tool, either. Dolphins engage in sex as social bonding. Canines engage in sex as dominance display. Some birds do social bonding sex as well.

Holy crap, hyenas. Kinkiest animal sex I know of.

You don't think that might be a bit outside the species concept box that we're all taught in high school?

What we're taught in high school is good enough for day-to-day use for most people. Biologists can get into more into the details, but how does that benefit us as a society to teach all the details at a high school level?

I'm neither; I'm just a layman with an interest in the subject, but again; you can get as much detail as you need or desire. That doesn't really invalidate the high school education as workable more than nine times out of ten.

 

[Raven Crowking]

There was a nice look at speciation in Scientific American not too far back, in which the value of the idea of species (in light of recent evidence) was examined from several angles.

This link might be of interest:

What Is a Species?: Scientific American

 

[Jeremy Ackerman-Yost]

What we're taught in high school is good enough for day-to-day use for most people. Biologists can get into more into the details, but how does that benefit us as a society to teach all the details at a high school level?

I'm neither; I'm just a layman with an interest in the subject, but again; you can get as much detail as you need or desire. That doesn't really invalidate the high school education as workable more than nine times out of ten.

Workable, sure. But fundamentally ignorant and incapable of informing policy in the modern age. We teach people that things are simple. We do it in a way that reinforces cultural biases.

Whenever the real world gets complicated, people think it's an aberration, because we spent high school and nowadays most of college telling them it was simple. They ignore new evidence because we let them believe that these topics are settled.

We tell them we understand things, because we want to believe we do, and we lie to them to comfort ourselves.

Some of these people go on to be executives and politicians who have to make decisions about science that can affect the lives of entire countries, if not the world. We don't need to give them all the details, but we do need to make them understand that they don't understand. I'm getting tired of running into closed minds who declare facts "impossible" because they contradict something taught to them in 9th grade.

As for what species concept "fuzziness" is relevant to the discussion... We can't decide if sapiens and neanderthalis are the same species or not, and we're passing judgment on whether they can successfully mate.

We're living in a fuzzy place. But the reaction of the average person to it isn't to get comfortable with fuzzy. It's to make bold, unsupported, partisan statements. I've been doing it myself for years with my insistence that they did mate, probably pretty often, but at least I'm leaning on a few eons of human behavior to justify it. People on the other side are leaning on.... what? Lack of evidence? That's a pretty thin reed on which to insist on a negative.

Umbran, I'm not explaining myself well. Let me clarify.

Some plants that are actually quite distinct, genomically, can reproduce, so you end up with, say, 3 copies of one set of chromosomes and 1 or 2 of a different one. The offspring are totally viable, and when they make gametes, those gametes might end up with one set of chromosomes, from one parent species or the other.

In this case, I'm not talking about polyploidy where all the chromosomes come from the same species. We're talking about gametes from a different species entirely being part of the mix. It's not an every hour, every day occurrence, but it's not that rare, either. Usually they are closely-related species, but not always. If the gametes have some convergent or conserved properties and the chromosome number isn't too divergent.... some strange things happen.

The animal comparison would be if 3 dogs and a cat got together and made one puppy out of their gametes. That puppy grows up and gives birth to a litter that's 75% puppies and 25% kittens.

I also think we must mean different things when we're talking about the species concept, because as it was taught to people in some college bio classes I've seen (to say nothing of high school ones), genetic exchange is only considered possible within a species. This is why I keep using the term "strict species concept" which is a different beast from some of the looser species concepts that have been floated since genetics came on the scene.

Besides all that, we got sidetracked with the animal behavior thing, so let me try to bring it back to point.

The fact that a lion won't mate with a tiger is irrelevant to the fact that a sapiens would sure as heck mate with a neanderthalis. Heck, sapiens have been known to mate with at least a dozen genera from multiple phyla of animals, and that's just counting the ones I can confirm from talking to doctors and vets I know who have been confronted with the evidence on a bad late night shift in emergency. I'm afraid to do Google searches for more examples.

Among most animals, there are limited contexts in which you will mate. Mating is energy intensive and risky. So birds look for the guy with awesome feathers and great songs and dances. Lots of female mammals will only mate with the dude with an awesome set of horns or teeth and who kicks a big, fat bag of ass. Many animals have specific seasons or conditions in which they mate, and will not do so outside those seasons. Many of them will look at coat color and shininess, muscle tone, and a dozen other things before choosing to mate, because they don't want to waste their resources and take risks by mating with something that is not in good health and in possession of good genes.

Big cats of one sort or another do almost all of these. Most of the larger primates do almost none of them, or selectively apply them at some times and follow alternative strategies at other times. Primates in general are so social that they're willing to co-opt almost anything as a social tool, regardless of how energy intensive or risky it is. And we took physiologic steps to make mating less risky overall.

And hominids, IME, are a more complicated mess altogether even than "lower" primates. We apply all of those strategies or none of them at all depending on the social conditions. We mate for social dominance, both of the person we're with and of distal people. We mate because we're bored. We mate because we're excited. We mate to obtain non-mating resources. We mate out of curiosity. We "mate" with other species often enough to have entire industries devoted to it, not to mention a plethora of historical anecdotes about famous people. We break our established mating patterns at rates even greater than the more wandering among the songbirds, many of whom are utter sex fiends (yet most science texts still insist they are broadly monogamous, in the face of a couple decades of compelling evidence and a couple centuries of anecdotal evidence from the field. Why would we do that? ... Well, that loops back to my cultural narrative concerns).

Lions (mostly) live in groups. Tigers (mostly) live solitary. Their behavioral mating games are quite disparate. Both of the human subspecies in question lived in groups and were probably following the broad strokes of the social mating schemes followed by social primates in general: Dominants and Cheaters is a succinct description, though I admit it leaves a lot out. And that's leaving aside the human adaptation of total war wherein females are mostly noncombatants to be used as chattel after a battle. That's quite distinct from the model used by other primates, wherein the females tend to be combatants if they are not currently caring for an infant. If that human model of tribal warfare was in play by the time Neanderthals and modern humans were bumping into each other, you can bet there was a TON of mating. Sure, lots of the females would be killed before they gave birth, or the babies would be left to die, or any number of other fun things humans do with inconvenient children, but a few always survive.

Lions probably see that striped fur and lack of mane and think "that guy must be sick. Run AWAY!" Humans see a person with an exotic look and they think, "Man, mating that would really irritate my parents! And I bet they're wild in the sack."

And, frankly... neanderthals weren't even all that exotic, physiologically. They probably fit in at the family reunions better than most people on this forum do today. After all, they were just sort of big-browed and had slightly inferior tools... we're nerds.

In short, the fact that lions and tigers don't typically mate has absolutely no bearing on the human question, and I'm sorry I brought it up.

 

[Jeremy Ackerman-Yost]

Also, on the fungi example..

Some fungi that we consider one species are actually several species of haploid cells growing in a mixed-species colony. Their diploid stage might be some other "species" entirely. And then sometimes two haploid fungi of different species manage to randomly create a diploid pairing that works.

Those are fun. They're like a dog, a rat, a chimp, a human, and a narwhal dropping some gametes together in a spot such that they would clump together and grow into an oak tree. That oak tree would grow up and produce seeds. Those seeds would then grow into new dogs, rats, chimps, humans, narwhals, and every once in a while a unicorn and a hippogryph, but only paired like that, except on alternate Tuesdays, when they produce dragons and dung beetles.

You don't think that might be a bit outside the species concept box that we're all taught in high school?

Not too terribly, no. What you've demonstrated is that creatures with only small amounts of cellular differentiation can sometimes experiment a little with their genetics.

I think that's significantly understating the case.

In the other stages of their life cycle, some of those fungi don't have much similarity to each other at all. Some of them only form fruiting bodies in combination with other species that are genetically about as far apart from each other as humans and maybe birds, if not humans and seahorses.

In my "closer to home" example, that would be if oak trees could only be formed by a combination of animal gametes. And the animals could choose to reproduce that way or by typical means.

This by no means blows the entire concept out of species out of the water - it merely indicates we have to be a little careful in discussing it sometimes

I don't think it blows it completely out of the water. But it calls it into question in many cases. My worry is that we're too convinced we understand things that we don't, and that we over-generalize. Something that works right most of the time for most animals and kinda sorta some of the time for most other forms of life does not deserve to be enshrined as a Rule. Teaching it as such and then saying, "Oh, yeah, I guess there are some exceptions and grey areas that really aren't all that important" is intellectually dishonest, at the least.