left biblioblography: LIGERS AND TIGLONS AND URSIDS, OH MY! –EVOLUTION IN THE MAKING

Tuesday, December 26, 2006

LIGERS AND TIGLONS AND URSIDS, OH MY! –EVOLUTION IN THE MAKING

Here’s another flashcard in the ongoing debates about evolution.

We’ve all heard the tired old refrain – “Show me where new species have come into existence!”

And so, I give to you, ligers, tiglons, and ursids.

Also wholphins, coydogs, dogotes, coy-dingoes, guin-hens and pea-guineas, dzos and zorses, not to mention zedonks and zonies.

These are all interfertile species, known as hybrids.

Of course, the response will be: “Hey, the horse is an entire species!” or “Hey, tigers and lions are all the same species, they’re cats!”

Not even close. Kinda like saying a tree and a weed are in the same species. Family? Yes. Species? No.

The Science dictionary defines it as “In biology, the classification lower than an order and higher than a genus. Lions, tigers, cheetahs, and house cats belong to the same biological family. Human beings belong to the biological family of hominids. (See Linnean classification.)”

Linnean classification catalogues it thusly: “A way of organizing living things. In biology, plants and animals have traditionally been classified by the structure of their bodies, in a descending hierarchy of categories: kingdom, phylum, class, order, family, genus, and species. For example, human beings are classified as belonging to the animal kingdom, the phylum of chordates, the class of mammals, the order of primates, the genus Homo, and the species sapiens.

The scheme is based on a system developed by the Swedish scientist Carolus Linnaeus in the eighteenth century.”

Note the phrase: descending hierarchy – the list ascends, top to bottom, species being the bottom rung of the ladder.

That out of the way, let’s looks at the wholphin, that mix of Flipper and a fake Shamu.

“A wolphin or wholphin is a rare hybrid, formed from a cross between a bottlenose dolphin Tursiops truncatus (mother), and a false killer whale Pseudorca crassidens (father). Although they have been reported to exist in the wild, there are currently only two in captivity, both at the Sea Life Park in Hawaii.”The next portion, while it illustrates natural selection perfectly, regrettably, shows why they aren’t all that prolific:

“The wolphin proved fertile when she gave birth at a very young age. The calf died after a few days. However, in 1991, Kekaimalu gave birth once again, to daughter Pohaikealoha in 1991. For 2 years she cared for the calf, but did not nurse it (it was hand-reared by trainers). Pohaikealoha died at age 9. On December 23 2004, Kekaimalu had her third calf, daughter Kawili Kai. This calf did nurse and was very playful. Only months after birth, it was the size of a 1-year-old bottlenose dolphin.”

What about the liger, you ask?

“The liger is a cross (a hybrid) between a male lion and a female tiger. It has also been known as a lion-tiger mule. A liger looks like a giant lion with diffused stripes. Some male ligers grow sparse manes. Like tigers, but unlike lions, ligers enjoy swimming. Unlike other hybrids, female ligers can reproduce.

A cross between a male tiger and a female lion is called a tigon. [1] This would have referred to the Gir Forest in India where the ranges of Asiatic Lions and Bengal Tigers overlap. Under exceptional circumstances it has been known for a tiger to be forced into ranges inhabited by the Asian lion, Panthera leo persica, which is the same genus as the tiger. Reports have been made of tigresses mating with lions in the wild and producing offspring known as ligers.”

And before you cry ‘Mule!’, witness:

”Male ligers are sterile, but female ligers are fertile and can breed with tigers (resulting in ti-ligers) or to lions (resulting in li-ligers).
Ti-ligers are more tiger-like, having a greater percentage of tiger genes. Li-ligers are more lion-like, having a greater percentage of lion genes. The fertility of hybrid big cat females is well-documented across a number of different hybrids.
This is in accordance with Haldane's rule: in hybrids of animals whose gender is determined by sex chromosomes, if one gender is absent, rare or sterile, it is the heterogametic sex (the one with two different sex chromosomes e.g. X and Y).”

In most cases, it’s almost always the female that’s fertile, the male sterile.

And, for a taste of East meets West, there’s the yakalo:

“The bison (American "buffalo") has also been bred with the domestic Tibetan yak to create the yakalo. In Nepal, yak/cattle hybrids are bred using yak bulls with domestic cows or, less often, domestic bulls with yak cows. The yak/cow females are fertile, the males are sterile and the meat is generally considered superior to beef among gourmets. In Nepalese, the hybrid is called a khainag or dzo (male)/dzomo (female). A dzomo crossed with either a domestic bull or yak bull results in an ortoom (three-quarter-bred) and an ortoom crossed with a domestic bull or yak bull results in a usanguzee (one-eighth bred). As a result, many supposedly pure yak and pure cattle probably carry a dash of each other's genetic material.”

There’s actually a very, very long list of creatures that range from the Jaglion to the Lepjag, to Camas and the beefalo.

Not to be confused with chimeras, such as Lydia Fairchild, or the tortoishell cat.

And here, is the pivotal crux: if Ligers or Tiglons become extinct, then they can be brought back into existence, easily.

So carry this around in your backpocket: and the next time some creationist doof starts yapping about 'no new species', enjoy the resulting confusion when you spring this little ditty on their blinkered viewpoints.

Till the next post, then.

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20 comments:

karen said...

When the female hybrids are able to reproduce, are their offspring also infertile?


As for tortiseshells, I have 2 calicos and 1 tortoiseshell cat. I guess the calicos are also considered torties. They are all females. My males are both tabbys.

***OT***
Saw on the news tonight a story about cloned meat and milk soon to hit the grocery stores. Survey said 60% of people would have problems with consuming meat of cloned animals. I don't see why there would be any negative effects from it. I'd buy it.

karen said...

Shoot. I meant to say, are their MALE offspring infertile. Oops.

Mesoforte said...

Cool post KA, I'll have to remember it when I'm stuck arguing with creationists.

Krystalline Apostate said...

karen:
When the female hybrids are able to reproduce, are their offspring also infertile?
Only the males. I'm not sure about the interbreeding among the hybrids themselves, as they're few & far between.
Saw on the news tonight a story about cloned meat and milk soon to hit the grocery stores.
Hmmm...wonder if it'll taste substantially different?

Mesoforte said...

Hmmm...wonder if it'll taste substantially different?

I can see this on a Monty Python sketch

P1: "Hey, does this milk taste too similiar to regular milk to you?"

P2: "I say, I think this milk is from a clone."

P1: "Well, I can't say I'm impressed. Perhaps the milk from the genetically modified cows will taste better."

Then, the punch line police would have to come in because of the lack of a punch line.

Beowulf said...

“Species” is a modern, taxonomical term. Listing several compatible species capable of creating an ‘identity crisis’ will hardly create the “confusion” effect your looking for. Moreover, how exactly are hybrids incompatible with creation? Your premises seem to be predicated on the false assumption that creation was just as we see things today and any variation is incompatible. Yet, the phenomenon is hardly proof for evolution, however interesting it may be.

On a related note, here is something to think about:

“Darwin's theory of evolution by natural selection in particular is hopelessly metaphysical, according to the rules of etiquette laid down in the Logic of Scientific Inquiry and widely believed in by practicing scientists who bother to think about the problem. The first rule for any scientific hypothesis ought to be that it is at least possible to conceive of an observation that would contradict the theory. For what good is a theory that is guaranteed by its internal logical structure to agree with all conceivable observations, irrespective of the real structure of the world? If scientists are going to use logically unbeatable theories about the world, they might as well give up natural science and take up religion. Yet is that not exactly the situation with regard to Darwinism? The theory of evolution by natural selection states that changes in the inherited characters of species occur, giving rise to differentiation in space and time, because different genetical types leave different numbers of offspring in different environments... Such a theory can never be falsified, for it asserts that some environmental difference created the conditions for natural selection of a new character. It is existentially quantified so that the failure to find the environmental factor proves nothing, except that one has not looked hard enough. Can one really imagine observations about nature that would disprove natural selection as a cause of the difference in bill size? The theory of natural selection is then revealed as metaphysical rather than scientific. Natural selection explains nothing because it explains everything.”

http://bevets.com/equotesl3.htm


Basically yours,

~ creationist doof

Mesoforte said...

The first rule for any scientific hypothesis ought to be that it is at least possible to conceive of an observation that would contradict the theory... The theory of evolution by natural selection states that changes in the inherited characters of species occur, giving rise to differentiation in space and time, because different genetical types leave different numbers of offspring in different environments... Such a theory can never be falsified, for it asserts that some environmental difference created the conditions for natural selection of a new character.”

Wrong, natural selection is falsfiable. One observed example of special creation or spontaneous generation of a species would be negative evidence against the theory.

Krystalline Apostate said...

BF:
Species” is a modern, taxonomical term. Listing several compatible species capable of creating an ‘identity crisis’ will hardly create the “confusion” effect your looking for. Moreover, how exactly are hybrids incompatible with creation? Your premises seem to be predicated on the false assumption that creation was just as we see things today and any variation is incompatible. Yet, the phenomenon is hardly proof for evolution, however interesting it may be.
& I quote: “We’ve all heard the tired old refrain – “Show me where new species have come into existence!” Top of the post, case you missed it.

I think mesoforte just popped your entire balloon there. Natural selection is indeed falsifiable.

That quote of yours is...laughable. 'Oh, gee whiz, it fits anywhere! Therefore, if it works w/everything, it must be metaphysical!'
Philosophical sophistry.

Mesoforte said...

BF-

The same guy that wrote that quote wrote this-

Creationists have capitalized on scientific disputes among biologists on the details of the evolutionary process by pretending that serious students of the subject are themselves in doubt about evolution. Evolutionary study is a living science; as such it is rich with controversy about particular issues off detail and mechanism. Creationists have extracted published statements in those controversies and used them dishonestly to suggest that biologists are in doubt about the fact of organic evolution. Local school boards and students must clearly be impressed that scientists in universities seem themselves to be denying evolution. Bioscience September 1981 p.559

I find that strange.

Beowulf said...

MF

“Wrong, natural selection is falsfiable. One observed example of special creation or spontaneous generation of a species would be negative evidence against the theory.”

Special creation and/or spontaneous generation would not falsify natural section. For natural selection is a process of selection; not origin.

I don’t see why the observation is so strange. Richard Lewontin is an evolutionary biologist and geneticist and believes evolution to be a fact. However, he is also honest about his observations. His position is with evolution, but not withstanding his criticisms.

Krystalline Apostate said...

BF:
Waitaminnit:
Listing several compatible species capable of creating an ‘identity crisis’ will hardly create the “confusion” effect your looking for.
A lion & a tiger are 2 distinct species.
Here, let me repeat this part of the post, since your reading comprehension's not quite working well:
Lions, tigers, cheetahs, and house cats belong to the same biological family
Go back & reread the whole post this time. Please.

Beowulf said...

KA

& I quote: “We’ve all heard the tired old refrain – “Show me where new species have come into existence!” Top of the post, case you missed it..

I saw the statement, but you also followed up with “Of course, the response will be: “Hey, the horse is an entire species!” or “Hey, tigers and lions are all the same species, they’re cats!” Which is misleading because it’s not to claim they are the “same species”, but of the same “kind” (which is an exegetical question not a scientific one). Which brings back my original point; “species” is a modern, taxonomical term. Hence, “creating new species” does not help your case unless you just want play semantic tricks in taxonomy and define your way onto evolution.

That quote of yours is...laughable. 'Oh, gee whiz, it fits anywhere! Therefore, if it works w/everything, it must be metaphysical!' Philosophical sophistry.

Wrong, Lewontin was on conveying the tendency to substitute ideology for cognition. He happens to be a well respected evolutionist himself.

I would like to continue the discussion, but will likely be unable to respond. Thanks to both of you for your input.

Beowulf said...

“A lion & a tiger are 2 distinct species.”

Yes I know and apparently their “compatible.”

Here, let me repeat this part of the post, since your reading comprehension's not quite working well:
Lions, tigers, cheetahs, and house cats belong to the same biological family
Go back & reread the whole post this time. Please.


So they belong to the same biological family; what’s your point? I don’t see a problem with what I said and your statement. Challenging my reading comprehension just traffics more pronouncement than persuasion.

Krystalline Apostate said...

BF:
Yes I know and apparently their “compatible.”
Well, that's NOT what you said prior.
So they belong to the same biological family; what’s your point? I don’t see a problem with what I said and your statement. Challenging my reading comprehension just traffics more pronouncement than persuasion.
Creationists have a distinct tendency to demand to see a new species: here's proof.
Let's look at this, however:
Your premises seem to be predicated on the false assumption that creation was just as we see things today and any variation is incompatible.
I kinda went cross-eyed on that 1. WTF? Where'd you get that from? I don't do that: folks on YOUR side of the fence do that. I've not said any such thing, nor inferred it.
Which is misleading because it’s not to claim they are the “same species”, but of the same “kind” (which is an exegetical question not a scientific one). Which brings back my original point; “species” is a modern, taxonomical term. Hence, “creating new species” does not help your case unless you just want play semantic tricks in taxonomy and define your way onto evolution.
I think you're the 1 playing semantical tricks here, mein freund. I'm operating well w/in the parameters stipulated.
There's a fallacy in there somewhere, but I can't pinpoint it exactly.
Unless you'd like to dispense w/the whole Linnean classification method?
I know, it's terribly inconvenient at the moment.

Krystalline Apostate said...

BF:
Oh, hey:
Special creation and/or spontaneous generation would not falsify natural section. For natural selection is a process of selection; not origin.
You're actually right about that.
Despite Lewontin's impressive credentials, I don't agree w/this 1 bit:
The first rule for any scientific hypothesis ought to be that it is at least possible to conceive of an observation that would contradict the theory. For what good is a theory that is guaranteed by its internal logical structure to agree with all conceivable observations, irrespective of the real structure of the world? If scientists are going to use logically unbeatable theories about the world, they might as well give up natural science and take up religion.
I'm sorry, but that just sounds...stupid. 'logically unbeatable theories'? 'Conceive of an observation that would contradict the theory'?
He's of the Gould school, who don't like Darwinism.
I did like this, from answers.com: "Lewontin argued that while traditional Darwinism has portrayed the organism as passive receiver of environmental influences, a correct understanding should emphasize the organism as an active constructer of its environment. Niches are not pre-formed, empty receptacles into which organisms are inserted, but are defined and created by organisms."
THAT'S a statement that I can agree w/.
So thanks. Learn somethin' new everyday.

Mesoforte said...

Special creation and/or spontaneous generation would not falsify natural section. For natural selection is a process of selection; not origin.

I don’t see why the observation is so strange. Richard Lewontin is an evolutionary biologist and geneticist and believes evolution to be a fact. However, he is also honest about his observations. His position is with evolution, but not withstanding his criticisms.


You missed my point. I'm not talking about life spontaneously generating, but an entire species. As in, you have one of the precursors to humans and then suddenly, with no link to that precursor, the modern human species appears. That's what I mean by spontaneous generation.

Also, scientists have taken a less "hard-balled" approach to falsifiability for a while now. Nor is falsifiability the only determinate in what is science and non-science. I'm also very certain that if you could prove that species were created independantly of each other, that would throw a huge hole in macro-evolution.

Mesoforte said...

You missed my point. I'm not talking about life spontaneously generating, but an entire species. As in, you have one of the precursors to humans and then suddenly, with no link to that precursor, the modern human species appears. That's what I mean by spontaneous generation.

Adding on to this, its like suddenly getting a supremely complex structure from a singular cellular organism without any intermediate steps.

a guy said...

Hey,

I know this is an old post, but you seem to be missing some details on the subject. I'm actually a biology major, so I may be able to help a bit.

Evolutionary biology has about 25 ways to define species...pretty ridiculous, but makes sense when you understand the egos, careers, and grants at state: and commitment to one ideology or another.

But the most basic, general, posited definition is that a species is a group of organisms able to produce fertile offspring which are themselves fertile. In this case the hybrids' fertility depends upon sex, possibly attributable to various causes of why the males are not fertile. Yet the females are, so that lions and tigers are indeed a species...and female ligers and tyons are able to produce offpsring when bred to another lion or tiger; if you breed a lion with a tygon you get a li-tygon, and if you breed a tiger with a tyong you get a ti-tygon, and that pattern holds.

And by the way, a creationist's view would be more along the lines that you have to produce something new, not just a hybrid, or even two populations of incompatible individuals: the whole "information thing".

Hope this helps.

a guy said...

P.s. that is "grants at staKe" not "grants at state".

But one theory or variety of evolution will rely on this or that detail or consideration or opinion or definition...so depending on the information and interests involved so and so will assert this and so and so will asser that.

Krystalline Apostate said...

Hey, 'guy'?
I'm aware that there's some division among kladists (traditional vs. transformational).
Problem is, most creationists view things in terms of absolutes: "Tell me EXACTLY what a species consitutes?" & if your answer isn't written in stone, hollers of 'ah-HA!' rebound from the walls.
(Rarely is anything absolute, but go figure. A little fluidity is perceived as 'wishy-washy').
And by the way, a creationist's view would be more along the lines that you have to produce something new, not just a hybrid, or even two populations of incompatible individuals: the whole "information thing".
Yeah, there's no getting around the stilted idea of conjuring a new species outta thin air. They're a bit stuck on that.
Non sequitur that it is.