Have we halted our own Evolution?

Not biologically possible. The only way to 'halt' evolution would be to make time stand still. That said, our own culture, science and technology have become important selective forces in our own evolutiona, so yes, we are influencing our own evolutionary trajectory, in many ways inadvertantly. This is true. The consequence is an increase in what geneticists would term the 'genetic load' of deleterious genes in our population. Half true. We *intend* to make our immediate environment more amenable to our comfort and security, but these are short-term efforts with long-term costs that will eventually backfire on us. E.g. we burn fossil fuels to have warmth in winter, but we are accelerating global warming that will eventually have far more deleterious effects on us than the localized seasonal discomfort of cold winter weather. Absolutely not. We may need to evolve resistance to a thousand different environmental pollutants to have a chance at survival even 100 years from now. That's anyone's guess, but as you recognize, we are now important determinants of our own ecological fate, evolutionarily or otherwise. At the rate we are going, we may be lucky to avoid extinction as a species 200 years from now. The only chances for an ultimately positive outcome are (1) stabilizing the human population at ecologically sustainable levels, estimated at around 2 billion people (fat chance of that) and (2) reversing our imminent descent into environmental degradation and contamination for sake of immediate comfort and material wealth (not much chance of that either). Sorry, it's pretty bleak. We won't have a chance to evolve much further physically in the scant few generations it will take for us to completely destroy this planet - unless you believe we will somehow develop technology for a self-sustainable existence on other planets. Good luck.

Thankfully for humanity, 'addiction to work' is still a reality for some of us.

You are making the rather tenuous assumption that mate selection (for purposes of actual reproduction) will be based soley on overt physical features, rather that intelligence, or sufficient education to de-frock surgically created 'beauty'. Michael Jackson comes to mind. Besides, nowadays we can just screw the heck out of stupid pretty sex partners using condoms and hold out to marry a passibly attractive intelligent one.

I can see your angle, but I think sexual selection (active mate choice) is still a very powerful force in human evolution. As RazD has pointed out below and in another thread on this subject, creativity and other important correlates of intelligence have become criteria for mate selection in humans and likely led to 'runaway' selection for particular traits, intellect being first and foremost. This process continues in modern human populations. Physical traits might be attractive sexually, but remember we have effectively divorced 'recreational sexual actitivy' from 'reproductive sexual activity'. We might sleep with someone of lower IQ, but we are unlikely to marry and have children with them. And intelligence does have a high degree of heritability, believe it or not.This message has been edited by EZscience, 04-11-2006 08:56 AM

Quite true, but it doesn't have to be 100% in order for sexual selection to be a powerful force. There are always going to be unplanned pregancies with partners who would not be considered marriage-worthy, but the majority of human births are planned and occur specifically with a mate of one's own choosing. That's all it takes for mate choice criteria to have a big effect on the direction of human evolution, particularly assortative mating scenarios where the same trait is a criterium for choice in both sexes. Most biologists would say that the effects of genetics and environment on phenotype development are multiplicative rather than additive - if either is zero, the product is zero. But don't assume that a role for environmental influences will diminish in any way the power of selection to change a trait. There need only be 'some component' of heritability to the trait for selection to be effective. The trait doesn't have to be discretely heritable.

consolidation of the pair bond?
diversion of otherwise aggressive male tendencies?
gratification of the basic male desire to inseminate?I wonder how many cases of spousal murder are associated with wives withholding sex from their husbands ?(ABE) ...and it wouldn't be because they were wanting another baby.This message has been edited by EZscience, 04-11-2006 02:37 PM