Monthly Archives: December 2008

A manly march out of Africa

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I like to imagine what life might have been like for our ancestors.  You can do this with any time period — going back to your great-grandparents, or a few centuries before that, or way back in evolutionary time.  In today’s case, how about 60,000 years ago?

That’s the era when Homo Sapiens were migrating from the Africa to the Middle East, and spreading from there to populate Asia, Europe, Australia and the Americas.  These people were anatomically the same as us.  And it’s surprising how much anthropologists have been able to deduce about them:  They were hunter-gatherers, and probably their lives were similar to hunter-gatherer communities that persisted into the 20th century.

And now there’s evidence that the bands of migrating humans, who probably worked their away across what we now call Egypt and the Sinai, included more men than women.  Alon Keinan of Harvard Medical School, and colleagues, used genetic markers to detect a surprising anomaly in human DNA that must have been triggered about 60,000 years ago.

They compared the genomes of modern people of West African descent with people of European and Asian descent.  The non-Africans show a series of random changes in their X chromosomes, known as “genetic drift,” which only seems to make sense if non-Africans all descended from a group where men outnumbered women.

(I’m skipping over the scientific methods for making these calculations, but it’s worth noting that this type of analysis is possible only using the tools developed for the Human Genome Project.)

We may never be able to say with confidence why those bands of people left.  A writer at New Scientist speculates that warfare might have played a role — that the migrants might have been similar to marauding Vikings.  Or, at the least, they may have been like more recent examples where male explorers and settlers went first (and women were in short supply).

This doesn’t imply that gender relationships back then were structured in any specific way.  But, it’s fair to imagine a charismatic leader, a visionary, whose name we’ll never know, who led early exploring parties up the Nile River, and out of Africa — 60,000 or more years ago.  The first “age of exploration”?

The study was published this month in Nature Genetics.

Malaria and the Holy Grail

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Ah, the dilemma of Hope vs. Hype. I reported earlier this week that medical researchers and global health activists (including many at PATH in Seattle) are feeling a bit of success in the latest test of a malaria vaccine. It appears, so far, to be the best hope for protecting people living in malaria-infested areas. Malaria kills about a million people every year, mostly children in sub-Saharan Africa.

What I only mentioned, but didn’t have time in my radio report to explore, was the fact that the vaccine is still barely more than 50% effective. There’s no telling whether it will be better or worse than 50% once it gets into a less controlled context, in a final field trial that starts next year.  It likely will leave roughly half the population unprotected.

There are other potential malaria vaccines in the pipeline.  If any of them proves practical and at least partially effective, then you might combine two vaccines, and maybe make a big difference.  This would be like creating the “cocktail” of drugs that are helping AIDS patients survive.

Other researchers say we need a vaccine that’s at least 90% effective, ore else we’re going to allow malaria to remain the scourge of Africa.  But, there are vast challenges (scientific, technical) in creating a vaccine that good.  One candidate comes from Stefan Kappe’s lab at Seattle Biomedical Research Institute.  You can listen to my profile of him from last year, or read a recent profile by Luke Timmerman at Xconomy.com.

And, there are entire websites devoted to debunking all this as hype.

I think it’s great for science and possibly for human welfare that the Gates Foundation and others are funding this research into malaria.  But, for the next decade at least, it looks like old-fashioned remedies will have to do.

Flunk that report card

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Do Washington state residents have some of the worst access to emergency medical care in all of America? That’s what a reputable organization would have you believe. The American College of Emergency Physicians issued what they call a “report card” on the 50 states. They rank Washington at the very bottom when it comes to availability of hospital beds and psychiatric beds, and near the bottom in the availability of registered nurses.

But, the state Department of Health has no evidence of such a severe shortage. Spokesman Donn Moyer asked the various data-crunchers within the agency, and they concluded, “This isn’t how we would quantify access to care.” He says they can’t understand why the Emergency Physicians would measure hospital beds “per capita,” because that’s not a method that’s typically used in the world of public health.

What does this mean?

(a) there’s a hidden crisis brewing in Washington, unseen by our officials, with people getting turned away in growing numbers as they seek hospital care

(b) having fewer hospital beds in your state does not automatically translate into lack of access to care by people who live in that state

(c) an interest group has created a report that – surprise – serves the interest of its members (by advocating for more spending on hospitals and medical staff)

I would go with both (b) and (c). To believe (a), you’d have to think everyone at hospitals and in the emergency medical system is keeping quiet about a major problem, which is worse here than the rest of the country. And, they only decide to speak up when ACEP releases its bi-annual report.

Do “diversions” happen, when an Emergency Room is full, and a patient is sent to an E.R. that’s not necessarily the closest? Yes, but that also might be a sign that we’re using the medical system efficiently. What do you think?