I don't think the HIV status of the father matters. The child contracts the virus mostly through the mother's blood as the virus passes through the placenta. The only way the father can pass on the virus to the baby is if he infects the mother, and the mother infects the baby. In other words, sperm does not carry the virus. I'm talking sperm cells here, not semen. Semen does. Be safe.

As for statistics, it is not 100%. According to this study:
Vertical transmission rates for HIV in the British Isles: estimates based on surveillance data. British Medical Journal Nov 6, 1999, v319 i7219, p1227

The rate is 20% with normal birth for pregnant ladies not on Anti-Retrovirals. Cesarean is higher at 32%. With Anti-Retrovirals, the rate drops to 2% and 4% respectively. Of course, there are also some who contract the virus within 6 months of birth from breast-feeding.

Be mindful these statistics are from one particular population, so might not be representative of all humans.


As far as I'm concerned, anti-HIV antibodies are ineffective against the virus. So even if it was passed on from the mother, I doubt the baby will have immunity.

Hope that helped.

EDIT: sucky grammar.

This post has been edited by thesupertramp: Jan 5 2010, 10:04 PM

Did you read the question that was asked? I was answering a question, not discussing incest. If you have a problem with that, you should have asked why was that question asked in this thread.

I suppose the article has explained it?

Anyway, essentially, there is no such thing as a "perfect race". (Contrary to those who believe God created humans). A species's survival is based on variability, ie, mutations. Inbreeding would create one and the same. If conditions on earth were to remain the same forever and ever, this would not be a problem. But as we know, "the only thing that never changes is everything changes." Hence, the variation is important in creating individuals that can survive in this "new" condition. Of course, this also creates individuals that are less suitable than before to this new condition. That is where natural selection comes in. The weak will parish even before they pass on their genes, and the fit survive, and reproduce.

A hypothetical example would be, if one day Oxygen level were to drop too low that our current lungs cannot absorb this gas, then without variability, ie, if everyone's lungs are identical, it would be Goodbye Homo sapiens. However, if mutations occurred and there are individuals with lungs capable of absorbing low levels oxygen, they will survive, and reproduce. Homo sapiens survive.


As for inbreeding at the initial stages of humanity, no, that is a misunderstanding of evolution. Evolution is gradual. There is never a clear jump from one species to another in the evolutionary process. Only in retrospect would we have seen the difference, as we can compare the two fossils that date millions of years apart. Hence, the "first few humans" on earth were most likely not very different from their parents. So, unless their population was wiped out until a few of them remained, I don't see how inbreeding was necessary. I hope you get what I mean.

Why we don't mate with apes? It is because the variability of that would be too high, resulting in too low a survival rate for the newborns. To me, high variability may be good, but it is not necessary since the Earth's condition does not change rapidly, but gradually. (except for a few times in the last 3 billion years, which as we know, resulted in many species disappearing). Therefore, no reason for that compromise.

This post has been edited by thesupertramp: Jan 7 2010, 06:50 PM

Bestiality aka zoophilia is illegal in most countries. I don't know the exact reasoning but I would hazard a guess that it is because of health and safety reasons. Infectious diseases could be spread that way. Like AIDS (possibly, not saying it is). It is also mistreatment of animals, because I doubt they want to "get it on" with you. Most anyway.

I disagree.

Modern medicine has increased human life expectancy by leaps and bounds. That, surely, must mean an increase in survivability? Living longer will allow a longer period for reproduction as well as nurturing the young. How can that not increase survivability?

Furthermore, many diseases can affect almost every human given the chance, regardless of how strong the individual is. And a car can hit anyone, even Arnold Schwarzenegger will need a orthopod when a bus hits him (or a funeral parlour).

I still disagree. Humans have used medicine to treat themselves for thousands of years, possibly millions. Other animals have shown similar traits as well (dogs eating grass). Now, although Lamarckism is distinct from Natural Selection, it does play a significant role in a species's survival.

It is true that genetically our genes might not be "better" due to medicine, but the use of modern medicine can be equated to similar traits demonstrated by other primates, such as calling out when they see danger so that their entire group can flee. Thus, both forms can be said to provide evolutionary advantage to a species, but Darwin's evidence seem to suggest team work is more important. In The Descent of Man, he noted that tribes that demonstrated better team work usually triumph over those that do not.

My point isn't about the differences between the effects of natural and modern medicine. The point is that humans have the unique ability to use tools. Modern medicine can be seen as one of humankind's greatest tools. Arguing medicine is counter productive to evolution would be similar (perhaps the same) as arguing the invention of guns have made the weak able to hunt for food, when in fact they should be left to die. Or the use of clothes have ensured the survival of those with less adipose tissues.

The use of tools is part of our evolutionary history and since we still exist, it can be said that it has served us well so far.

I was not referring to Lamarckism in its traditional sense. Genes cannot be altered, I know that. I was referring to the passing on of knowledge. We do not pass on knowledge of medicine genetically, but we do so in the form of books, lectures and teachings. In a sense, this is not Lamarckism, but it is close. We acquire that knowledge throughout life and pass it on. This ability to pass on knowledge is immensely significant in many species's survival.

Perhaps this is more akin to the Meme theory. If it is, then that further supports my point as modern medicine has grown and flourished.

Not necessarily. Evolution did not end when humans started using tools. Because of our use of tools, more importance have been placed on intelligence. And as such, our brain size have increased. The tools only hinder our evolution if you do not consider all the "tools" we invented as part of our lives. Artificial or not, it is now part of humanity. Taking away houses from humans is similar to taking away trees from monkeys. We have evolved such that the essential tools we have created are part of humanity, part of our species. Of course, not all tools are essential, like iPhones. Natural or not, we have thrived with it, just like monkeys have thrived on trees.

A catastrophe can wipe out human knowledge which would set back humanity. True. But the same can happen if a catastrophe wiped out all the trees. Monkeys would then have to evolve to adapt to life on land (non-tree land. What's the word? Terrestrial?), or face extinction. That is what humans would have to do should that happen, regardless of whether we live in houses or in caves.

http://en.wikipedia.org/wiki/Lamarckism#La...societal_change
Knowledge can be considered part of our culture. Your example presupposes that all knowledge is passively transferred. Knowledge is more often actively transferred than passively transferred (that is until they invent that Dexter-learning-French-in-his-sleep device). Cultures are very often passed down from one generation to another.

Catastrophe, refer above. Also, with the increase in intelligence, I would presuppose that humans will return to where they were before in a shorter time than it took them the first time. Though I admit, that does not mean it will not take millions of years, just shorter. Hopefully some books survive.

EDIT: Grammar.

This post has been edited by thesupertramp: Jan 14 2010, 10:55 PM