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"All the research into the past is fascinating but I'd really like to see where scientists think that human evolution is occuring most today. Is it in areas with large numbers of births and deaths? It seems like advanced countries have lower birth rates, which goes counter to evolution."

I have an idea that I've been working on for a while, here it is:

Evolution is occuring every minute, every hour and every day of every year all over the world. Let's take humans.
Women have something called 'spontaneaous abortion' where the union of an egg and sperm is made and immediately aborted, many times even without the knowledge of the woman because of an anamoly.

Now, let's say that anamoly is drugs or pollution. Any pregnacy that makes it to term has made it through the 'spontaneous abortion' barrier because it was a union strong enough to withstand the drug or pollution (or a hundred other factors) present at the time of conception.
I believe this is a continuous 'weeding' process and only the 'strongest' unions survive. I also believe that some retardation at birth is due to causes similar to the one mentioned and the retatded person born was at the bottom limit of the survivability level.
I expect that many of us are 'immune' to many things we would be suprised to learn.

This is a continuous process and if environmental conditions change dramatically , only a small handful of us would survive to pass on those genes.

Women have something called 'spontaneaous abortion' where the union of an egg and sperm is made and immediately aborted, many times even without the knowledge of the woman because of an anamoly.

The total miscarriage risk, starting from fertilization, is extremely high at around 60-80%. By the time you see a heartbeat on an ultrasound at 6 weeks LMP, the risk drops to 5-10%. I think this can be considered "maintenance" more than evolution as it involves the filtering of gross genetic errors.

I guess I go back to the line in "Jurassic Park" where the mathematician says "life finds a way". For example, in advanced countries with declining birth rates, it turns out that the very technology that allows for declining birth rates also allows for directed evolution. Science is unravelling/understanding the genetic code while simultaneously providing a way to control reproduction (eg. IVF with PGD). It's only a matter of time before the two are combined. This was explored in the movie Gattaca and other sci-fi works. In another 50 years, this technology will be available to millions of people and many will find it irresistable when starting a family (imagine almost guaranteeing that your child won't have a chronic disease).

I guess it comes down to a battle between natural evolution and human-directed evolution. Which will win?

Evolution is occuring every minute, every hour and every day of every year all over the world. Let's take humans. Women have something called 'spontaneaous abortion' where the union of an egg and sperm is made and immediately aborted, many times even without the knowledge of the woman because of an anamoly.

Don't forget that the odds against a sperm cell are a hundred million to one in the swim competition. Overall, the chances of any particular individual surviving to reproduce are about a billion to one.

Just in case anyone tries to make that case that most mutations are detrimental.