Cross breeding, need help.

[aSnakeLovinBabe]

They are jut far too diverse, not just looks though, even in their actions! Especially the pickeringii. When I look at my pugets, then look at my easterns... then over at the cali red sideds.... well, you get the idea.

[ConcinusMan]

I guess a line has to drawn somewhere. Approximately 98% of our DNA is present in chimps' DNA. In other words, genetically speaking, we are 98% chimp. It's the other 2% that makes us human; a separate species. Recently extinct (in geologic time, around 30,000 yrs ago) species of our genus HOMO such as Homo erectus are actually in many circles considered a subspecies of Homo sapiens called H. sapiens neandertalensis. Others consider us to be a separate species. There is even some evidence that neanderthals contributed some genes to modern humans prior to leaving africa and evidence that cross breeding did occur at some time and locations.

My point is even if it happened far in the past; cross breeding erectus with sapiens; even though they are considered separated only by subspecies; it's fairly apparent that it would still be considered cross breeding. We now have the fortune of being the only species OR subspecies of Homo left on earth. So, the various human "races" we see on earth amount to nothing but a "form" of the same species as Stefan-A mentioned when speaking of grey wolves compared to modern dogs.

All that said, DNA or RNA mapping of all the so-called sub-species of Thamnophis sirtalis has not been done completely(as far as I know) and for now, I consider the various sub-species of sirtalis to be far enough separated to be treated as seperate species; far enough apart as we are apart from neanderthals even though successful breeding and healthy offspring can be produced by crossing the two.

Don't even get me started on plants. Broccoli and cauliflower and brussel sprouts are considered the same species. All modern lettuce varieties are the same species as inedible wild lettuce and often the two cross breed. All of this just reaffirms my belief that evolution does happen, even if life was created rather than spontaneously generated.

[Stefan-A]

I guess a line has to drawn somewhere.

But does it, really? Under some circumstances, I can see the advantage of working with a simple snapshot of the current situation, but it's not helpful when time needs to be taken into consideration. What I mean by this, is that there's no place to draw the line between generations, in order to separate one species from the previous, or the next. The result of such an attempt is that the two species get separated based on an almost arbitrary difference. And in my opinion, a valid system wouldn't have that problem.

Approximately 98% of our DNA is present in chimps' DNA. In other words, genetically speaking, we are 98% chimp. It's the other 2% that makes us human; a separate species.

Here's the problem: Our ancestors diverged a few million years ago. Assuming that we could point at a generation and declare that that's where the two lines separated, what percentage actually set the two lines apart? It would have to be so minimal, that we couldn't even distinguish it.

Considering that subspecies are diverging, you might as well treat them as full species. Isolated populations, too. If they don't become extinct, or once again connected to the parent population, they will continue to diverge. They are already on that road and that's why I don't make a distinction between creating hybrids between species, and creating hybrids between subspecies.

So, the various human "races" we see on earth amount to nothing but a "form" of the same species as Stefan-A mentioned when speaking of grey wolves compared to modern dogs.

I'm inclined to agree, but I'd say that even the term "form" would be too strong to describe the human "races". Our most recent common ancestor was a mere 5000 years ago and we have essentially no reproductive isolation. Like a popular science magazine stated in a recent issue, there are fewer genetic differences between any two humans in the world, than between two gorillas from the same forest.

[aSnakeLovinBabe]

Considering that subspecies are diverging, you might as well treat them as full species. Isolated populations, too. If they don't become extinct, or once again connected to the parent population, they will continue to diverge. They are already on that road and that's why I don't make a distinction between creating hybrids between species, and creating hybrids between subspecies.

I have never felt there should be a distinction for this exact reason! well said

[mustang]

just out of curiosoty if we (like the grizzly/polar bear incedents) as in a sick twistede individual was to mate with a chimp would an old / new species be formed/reformed?

[Stefan-A]

just out of curiosoty if we (like the grizzly/polar bear incedents) as in a sick twistede individual was to mate with a chimp would an old / new species be formed/reformed?

The Soviets tried it, doesn't work.

Humanzee - Wikipedia, the free encyclopedia

[ConcinusMan]

OK, so it doesn't work. My conclusion then is that there is definitely a distinction and we are indeed separate species. But it does work (crossing subspecies) for sirtalis, so...

I guess the question still remains. Are the various subs of T. sirtalis different enough from one another that they should be considered separate species or not?

Hmm... intriguing.

[Stefan-A]

I guess the question still remains. Are the various subs of T. sirtalis different enough from one another that they should be considered separate species or not?

Depends on the definition.

[mustang]

left part of my brain: ME NO LIKE BIOLOGY....TOOO MANY BIG WORDS TO MEMORIZE!!!!!!!!!!

[mustang]

right part of my brain: i passed with an 86 overall so lefty get over yourself