Chap wrote: That depends how 'close' would be close enough for you. We cannot interbreed with chimpanzees, although even on recent reduced estimates we still share 95% of our DNA with them:
It isn't what is close enough for me. It is what is just one step away from interbreeding. So theoretically speaking, could there be human populations on earth at present which could not interbreed?
There are certainly individuals who cannot interbreed. I don't think it's really accurate to say that all couples experiencing fertility problems do so because something is "wrong" with them. It could just be a case, for some of them, of genetic changes resulting in a reduction in their viability with each other. There are probably couples who conceive only with difficulty, where the woman might well conceive easily with a different man, or a man might more easily sire offspring with a different woman.
Are there whole population groups today that would have trouble breeding with other population groups? I don't know. It wouldn't surprise me, however, if there were fertility problems between humans of today and humans of, say, 80,000 years ago, even if we're both still "human". Again, keep in mind that it's not a simple yes/no, fertile/infertile answer. Viability for reproduction can be affected by degrees.
Mormonism ceased being a compelling topic for me when I finally came to terms with its transformation from a personality cult into a combination of a real estate company, a SuperPac, and Westboro Baptist Church. - Kishkumen
Sethbag wrote:There are certainly individuals who cannot interbreed. I don't think it's really accurate to say that all couples experiencing fertility problems do so because something is "wrong" with them. It could just be a case, for some of them, of genetic changes resulting in a reduction in their viability with each other. There are probably couples who conceive only with difficulty, where the woman might well conceive easily with a different man, or a man might more easily sire offspring with a different woman.
I wasn't talking about couples who are genetically capable of reproducing, but may not be able to because of physical problems (scarred fallopian tubes, low sperm count, etc.)
Sethbag wrote:Are there whole population groups today that would have trouble breeding with other population groups? I don't know. It wouldn't surprise me, however, if there were fertility problems between humans of today and humans of, say, 80,000 years ago, even if we're both still "human". Again, keep in mind that it's not a simple yes/no, fertile/infertile answer. Viability for reproduction can be affected by degrees.
Charity, I'm going to make up some numbers for the sake of argument. It's the idea I'm trying to convey, not the specific numbers, but the numbers help convey the message, so here goes.
Let's say that Jack marries Jill. Jack's sperm have to be mobile enough to make up through Jill's cervix, into her uterus, up into the fallopian tubes, and then the coatings on the cell walls of the sperm and the coatings on the egg have to be such that some of these sperm might be capable of getting through the egg wall and fertilizing that egg. None of this is a given - Jack and Jill's very DNA must code for these things in such a way that they are compatibile. Let's say that, given a sufficient quantity of sperm, and a viable egg, a sperm of Jack's might be capable of fertilizing Jill's egg 70% of the time.
Would it surprise you overly much if there was a guy named Dan out there whose sperm might fertilize Jill's egg 80% of the time?
Would it surprise you if there was a woman named Ingrid out there whose eggs Jack's sperm might be able to fertilize 90% of the time?
What if Jack and Jill only have a 70% chance of fertilization, and Dan and Ingrid had a 60% chance of fertilization, but Jack and Ingrid had a 90% chance, and Dan and Jill had an 80% chance? Would that surprise you?
This is what I'm talking about. Sperm aren't exactly the same from man to man. Eggs aren't exactly the same from woman to woman. The specific properties of a given sperm and a given egg are derived (excluding the environment for the sake of this discussion) by the specific genes carried by the man and the woman. Because Jack, Jill, Dan, and Ingrid are all humans, their genes will generally encode for germ cells which are viable with each other. But that doesn't mean that the viability will be exactly the same across all members of the species. Their germ cells are still slightly different due to their DNA being slightly different. But they are still similar enough to be viable.
Now, let's say you separated Jack and Dan into different population groups which couldn't mix for tens of thousands of years. Let's say that Jack and Dan each have traits which cause their genes to be selected more than others in their local gene pools. So Jack's genes get propagated, and even changed further. Dan's genese get propagated in his local gene pool, and changed further. Think champion cows. Cows that give more milk than other cows will generally be bred specifically for that trait, so that ultimately you end up with cows givings significantly more milk than the original cows did. Think dogs who are bred for their running speed, or their powerful sense of smell, or whatever. Eventually you end up with dogs who run much faster than the original dogs did, or whose noses are much more sensitive than the original dogs did.
Would it surprise you too much if someday a descendant of Jack got together with a descendant of Jill, and it turned out now they only had a 40% chance of fertilization?
What if these populations separated long enough that many generations later their descendants could only fertilize each other's germ cells 20% of the time?
Can you really expect a "point" in time where all of a sudden each member of a given species suddenly cannot viably mate with each other member of a closely related species? Or should you, rather, expect there to be a more gradual reduction in their compatibility, resulting ultimately in complete, or nearly complete non-viability?
But remember Jack, Jill, Dan, and Ingrid. They're all humans, but they are not all equally viable. They are still genetic individuals, and their germ cells are still slightly different from each other because of this. And it's these genetic differences which grow larger and larger between gene pools that are not able to keep sharing changes through sexual reproduction, which eventually result in gene pools that differ enough that they are considered different species by humans.
Mormonism ceased being a compelling topic for me when I finally came to terms with its transformation from a personality cult into a combination of a real estate company, a SuperPac, and Westboro Baptist Church. - Kishkumen
Sethbag wrote:Charity, I'm going to make up some numbers for the sake of argument. It's the idea I'm trying to convey, not the specific numbers, but the numbers help convey the message, so here goes.
Let's say that Jack marries Jill. Jack's sperm have to be mobile enough to make up through Jill's cervix, into her uterus, up into the fallopian tubes, and then the coatings on the cell walls of the sperm and the coatings on the egg have to be such that some of these sperm might be capable of getting through the egg wall and fertilizing that egg. None of this is a given - Jack and Jill's very DNA must code for these things in such a way that they are compatibile. Let's say that, given a sufficient quantity of sperm, and a viable egg, a sperm of Jack's might be capable of fertilizing Jill's egg 70% of the time.
Would it surprise you overly much if there was a guy named Dan out there whose sperm might fertilize Jill's egg 80% of the time?
Would it surprise you if there was a woman named Ingrid out there whose eggs Jack's sperm might be able to fertilize 90% of the time?
What if Jack and Jill only have a 70% chance of fertilization, and Dan and Ingrid had a 60% chance of fertilization, but Jack and Ingrid had a 90% chance, and Dan and Jill had an 80% chance? Would that surprise you?
This is what I'm talking about. Sperm aren't exactly the same from man to man. Eggs aren't exactly the same from woman to woman. The specific properties of a given sperm and a given egg are derived (excluding the environment for the sake of this discussion) by the specific genes carried by the man and the woman. Because Jack, Jill, Dan, and Ingrid are all humans, their genes will generally encode for germ cells which are viable with each other. But that doesn't mean that the viability will be exactly the same across all members of the species. Their germ cells are still slightly different due to their DNA being slightly different. But they are still similar enough to be viable.
Now, let's say you separated Jack and Dan into different population groups which couldn't mix for tens of thousands of years. Let's say that Jack and Dan each have traits which cause their genes to be selected more than others in their local gene pools. So Jack's genes get propagated, and even changed further. Dan's genese get propagated in his local gene pool, and changed further. Think champion cows. Cows that give more milk than other cows will generally be bred specifically for that trait, so that ultimately you end up with cows givings significantly more milk than the original cows did. Think dogs who are bred for their running speed, or their powerful sense of smell, or whatever. Eventually you end up with dogs who run much faster than the original dogs did, or whose noses are much more sensitive than the original dogs did.
Would it surprise you too much if someday a descendant of Jack got together with a descendant of Jill, and it turned out now they only had a 40% chance of fertilization?
What if these populations separated long enough that many generations later their descendants could only fertilize each other's germ cells 20% of the time?
Can you really expect a "point" in time where all of a sudden each member of a given species suddenly cannot viably mate with each other member of a closely related species? Or should you, rather, expect there to be a more gradual reduction in their compatibility, resulting ultimately in complete, or nearly complete non-viability?
But remember Jack, Jill, Dan, and Ingrid. They're all humans, but they are not all equally viable. They are still genetic individuals, and their germ cells are still slightly different from each other because of this. And it's these genetic differences which grow larger and larger between gene pools that are not able to keep sharing changes through sexual reproduction, which eventually result in gene pools that differ enough that they are considered different species by humans.
Thanks. "I see now." Matthew Broderick as Phillippe in 'Ladyhawke.'
Seriously. Is that what is causing the rise in infertility? I thought a lot of it was scaring from PID's.
I don't know what all contributes to infertility in all cases. It's a whole host of things. I don't know to what extent incompatibility at the genetic level contributes, but I doubt it's all that much. I've read articles discussing hormones in our food and environment as being a problem, I know some women have scar damage on their tubes (that's my wife's problem, why we've only got one kid), some guys' fertility is lower because of the clothes they wear affecting their sperm, etc. There are all kinds of things.
Keep in mind that even if my hypothetical numbers were real, and one given couple only conceived 70% of the time and another couple conceived 90% of the time, both couples would still get pregnant fairly quickly given enough sex on days when the wife is fertile. It might happen on the first such instance with one couple, and take another couple two or three tries, but they'll still get it. True infertility would require much lower chances.
Mormonism ceased being a compelling topic for me when I finally came to terms with its transformation from a personality cult into a combination of a real estate company, a SuperPac, and Westboro Baptist Church. - Kishkumen
This goes back to the original post, but I've heard that in many ancient religions an individual born of a virgin was considered special and superior. Saying someone was born of virigin birth was just a way to say, "Wow, he's really special."
It's kind of disappointing but these explanations are starting to make a lot more sense than ideas you'd read in a New Testament religion class such as, Jesus was part mortal and part immortal. Than they say He was married to emphasize the importance of marriage, but where would that leave His offspring, 1/4 immortal?
And when the confederates saw Jackson standing fearless as a stone wall the army of Northern Virginia took courage and drove the federal army off their land.
ajax18 wrote:This goes back to the original post, but I've heard that in many ancient religions an individual born of a virgin was considered special and superior. Saying someone was born of virigin birth was just a way to say, "Wow, he's really special."
It's kind of disappointing but these explanations are starting to make a lot more sense than ideas you'd read in a New Testament religion class such as, Jesus was part mortal and part immortal. Than they say He was married to emphasize the importance of marriage, but where would that leave His offspring, 1/4 immortal?
Actually, the ancient religions are repeating their versions of the original truth preached to Adam and Eve. And remembered.
I understand the explanation on similarities between pagan faiths and Christianity. I lifted a quote from LDS.org so I think this doctrine is current.
The Savior's dual nature—man and God—enabled him to make an infinite atonement. First, he was able to assume the burdens and effects of the sins of all mankind and, in doing so, to engage suffering and anguish beyond what a mere mortal could endure. Second, he was able to submit to physical death, to willingly lay down his life and then take up his body again in the Resurrection.
So my question is, "What immortal characteristics did Jesus possess?" Would He have passed any of those characteristics on to His offspring if He had them? Is there an LDS answer to this question or is just unknown?
And when the confederates saw Jackson standing fearless as a stone wall the army of Northern Virginia took courage and drove the federal army off their land.
This goes back to the original post, but I've heard that in many ancient religions an individual born of a virgin was considered special and superior. Saying someone was born of virigin birth was just a way to say, "Wow, he's really special."
It's kind of disappointing but these explanations are starting to make a lot more sense than ideas you'd read in a New Testament religion class such as, Jesus was part mortal and part immortal. Than they say He was married to emphasize the importance of marriage, but where would that leave His offspring, 1/4 immortal?
Just a little FYI, I know of no mythologist, historian, or expert who even remotely would suggest that the myths and stories devolved from an original story as Nibley & Co. asserted.
Contrariwise, like language, myths and stories evolve and develop.
:-)
~dancer~
"The search for reality is the most dangerous of all undertakings for it destroys the world in which you live." Nisargadatta Maharaj