Monday, October 2, 2017

Definition of biological species

Jim : "Jaguars can mate with panthers. Therefore, jaguars are panthers? No."

CB:
Horses mating with donkeys produce mules; mules are infertile, sterile  , though viable. Therefore , horses and donkeys are not the same species .

Jim : "Yes, but not all hybrid animals are infertile. Hyenas, Wolves, Coyotes and Dogs can all inter-breed, and produce fertile hybrid offspring. Are hyenas and wolves therefore the same species?

Granted, if you define "species" as the ability to produce fertile offspring then your statement is correct, but that is not really the definition of species - which, as noted above, is fairly nebulous.  Some modern humans have Denovesan DNA, too. Not all homo erectus are homo sapien. "


CB: If they are not infertile, then they are not "hybrids" in the sense of different species.

Jim : "https://en.wikipedia.org/wiki/Coywolf"

What if they are selectively fertile, like how Ligers can mate with lion but not tiger?  According to your logic, a LIger is therefore a lion - not a hybrid? I'm not sure what your purpose in stating "neanderthals ARE homo sapiens" is ..?

Taken at face value, it's simple a false statement - i understand you may have some larger point, but I don't see it.

CB: "Taken at face value, it's simple a false statement - i understand you may have some larger point, but I don't see it.

https://en.m.wikipedia.org/wiki/Species

John : "You see that section, 'attempts at definition'? It's definitely a hairy question."

CB: Not hairy at all; very clear cut.

John : "Did you see the thing on 'ring species'? The whole first paragraph is basically giving a bunch of important exceptions which throw the whole rule into doubt."

CB : Just read what I said above. It's very logically tight .  Doesn't matter how they've been classified before the mating..
No they don't throw the definition in doubt . Just means the prior classification was wrong .


Jim : Homo sapiens and neatherthals belong to the same GENUS  - not species: "genus is higher than species"

https://en.wikipedia.org/wiki/Genus

CB : No Homo sapiens and Neanderthal belong to the same species, because they mated and produced fertile offspring ; because there are Homo sapiens living today with Neanderthal genes .
Homo sapiens Neandertalis

Mike : "Charles Brown , consider ligers. two species, mated, of the same genus, and produced a NEW species.
Neanderthal and homo-sapien are NOT the same species, they are both hominids, some of which may produce intermated offspring, of a NEW species, which may in some cases intermate within either original species.

When we consider Ligers, we note that a liger may be capable of mating with either parent species under the correct conditions, sex of the liger being a large determinant.

It's all well documented, how the mating within a genus might produce offspring, and the p
ossible and practical limits of interbreeding between offspring or parent species.



It seems likely that the offspring of neanderthal and sapien, produced offspring that was unlikely to successfully mate with neanderthal, and yet was highly capable of mating with sapien.

That along with local adaptations to conditions, eventually produced a single species, humans, with differences we see today.

CB: Ligers are not fertile; sterile, like mules .
If any are , just means the two that mated are the same species.


Mike : "Other Hybrid Big Cats

Because female ligers and tigons have proven to be fertile in some cases, handlers have bred them with lions and tigers. These pairings have also happened accidentally when a ligeress or tigoness was housed with a lion or tiger. For instance, a tigoness that mates with a tiger produces titiger cubs. These cubs, with 75 percent tiger parentage, mostly resemble tigers with few lion-like attributes. Lions and tigers have also been bred with other big cat species, such as jaguars and leopards. Leopards and lions have been bred together to create leopons and lipards. A tiger-leopard pairing is called a tigard."

You are seriously misinformed on the subject.

CB : Could have been anagenesis all the way back from homo Habilis or homo erectus , Mike Anderson. There's no such thing as hybridization in the sense of different species producing fertile offspring , because of the definition of species.

Ligers and mules are viable but not fertile. I use them as an example of a close case to explain the definition of species in my anthro classes.



Could have been anagenesis all the way back from homo Habilis or homo erectus , Mike Anderson. There's no such thing as hybridization in the sense of different species producing fertile offspring , because of the definition of species.

Ligers and mules are viable but not fertile. I use them as an example of a close case to explain the definition of species in my anthro classes.

No I'm seriously an expert on the subject. I'm an anthropology professor . What I say above is logically correct. If you don't get it , you are not thinking logically about it.



Mike: "You may teach, but are seriously misinformed, and may be teaching incorrect information.
You may wish that it is factually true that two distinct species within a genus CANNOT produce fertile offspring. And the reason you wish that to be true, is to support your flawed definition of species.

Too bad, your wish is of no concern to reality.

CB. : no I'm correctly informed. I understand it , and you don't. You are confused.


Mike: "Sir, to put a rather blunt point on it. Your position is absurd."

Harry : "If you are a professor you are aware of peer reviewed studies, not sure where Wikipedia fits in"


CB : I have many text books which corroborate Wikipedia . Textbooks are super-peer reviewed. Harry Green. On technical issues like this, Wikipedia is very good . There's no motive for anyone to

post bogusly.

No my position is strictly logical the opposite of absurd .

Harry : "Quote the textbook then" I have access to the library at college who, in turn, have access to many reputable libraries and textbooks

CB :
I don't care if _you_ believe me.  I'm casting pearls before swine with you. Your loss . You are stuck in ignorance and confusion.

Harry : "
perhaps i am confused here.
Are you saying then, that the tiger species, and the lion species are the same species?

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