Snakes, rats, cockroaches and spiders are very difficult to kill off. If we could, we would wipe them off, but even with modern technology, we can't get rid of them, back in the past it would not have been possible.

The reference to interbreeding with neanderthals is a single DNA study, and it does not say what you think it says. It says that non-african humans share a more DNA with neanderthals than africans. The shared DNA could have come from the exit point from Africa or some other location where everyone leaving Africa passed through (like the horn of Africa). The neanderthal breeding theory is not credible at all, because the strongest overlap between neanderthals and modern humans on a DNA basis comes from the far east, where there is no skeletal history of neanderthals existing.

You can read more about this here: http://en.wikipedia.org/wiki/Talk:Neanderthal_admixture_theo...

killing off spiders would be a god terrible idea. then who would kill your bugs?

We would, of course. Then we would manually polinate flowers and break down plant waste with chemicals.

Might as well kill all the flowers and plants too and just make food directly from organic chemicals in processes powered by solar panels and cut living organisms out of the equation completely.

Patience.

Is there actually a demand for killing off snakes, rats and cockroaches entirely?

I'm sure if we really thought long and hard...

Perhaps not, but there is a demand for killing off mosquitoes entirely, and in fact we've tried many times now...

We came close to succeeding with DDT, until emotions got the better of us.

Not quite -- we simply drew down the population of Anopheles enough that malaria was unable to spread. DDT is a very effective insecticide, but resistance has been described and can spread if it is overused; in fact it is estimated that agricultural use of DDT causes more deaths from malaria by contributing to DDT resistance in Anopheles and thereby affecting vector control operations.

See: http://www.nature.com/nature/journal/v293/n5829/abs/293181a0... -- http://localhostr.com/file/itFWMaa/zzz.pdf

"it can be estimated that at current rates each kilo of insecticide added to the environment will generate 105 new cases of malaria"

In short, it just ain't that easy.

Has anyone else got a crawling sensation on their skin?

This is a very recent discovery - the findings come from sequencing the Neanderthal genome by the Max Planck Institute.

http://news.bbc.co.uk/1/hi/sci/tech/8660940.stm

Whoa, I had no idea we had done that. Have we sequenced genomes from any human species?

edit: wikipedia and google searches haven't revealed any positives. Thanks for that link though, very interesting.

All of those other species you mentioned can hide from us easily, can reproduce relatively quickly, and/or can live in environments that humans can't survive in. Not so with humanoids.