W.D. Hamilton, malaria, and why evolution cannot be ignored

For my first X Vials post, I thought it fitting to blog about one of my favorite evolutionary biologists, W.D. Hamilton. I was reminded of him recently while browsing for something to read during a layover in the Atlanta airport. Inundated with the usual morass of pop culture mags (okay, I admit I bought one of those too-- to gawk at celebrities and feel out-of-touch for not knowing who any of them are these days), my eyes happened upon a National Geographic. On the cover of the July 2007 edition (Malaria: Stopping a Global Killer) is a stunning picture of the mosquito, Anopheles stephensi, carrier of the malaria parasite, a single-celled organism called a plasmodium. I immediately thought of Hamilton, who prematurely left this world on March 7, 2000 six weeks after contracting malaria in the Congo. After being rushed back to England for treatment, Hamilton at first seemed to recover, but then fell into a coma and died of cerebral hemorrhage.

Hamilton was described by his colleagues as a brilliant, deep, yet humble scientist (a refreshing combination amongst the egos in academia). He burned brightly, "shine[ing] like a violet ground beetle under a stone"-- the quote from Hamilton's essay, My Intended Burial and Why, in which he described his wish to be buried in the forests of Brazil upon his death. In the end, his body was placed in Wytham Woods, England where, instead of "escaping death" through the violet ground beetle, his essence has perhaps made its way into the many badgers that live there.

Hamilton is best known in evolutionary biology for deriving Hamilton's Rule, a simple and elegant mathematical statement predicting when individuals (usually closely related ones, as measured by their coefficient of relatedness, R) should cooperate with one another. In a nutshell, if the indirect fitness benefits (R*B) are greater than the direct fitness costs (C) of cooperation, then kin-based sociality can evolve. It is the basis for understanding kin selection, parental care, and the evolution of complex animal societies (think honey bees, naked-mole rats, etc.).

Hamilton also made significant contributions to the study of sex ratios and the evolution of sex (why do we need males anyway?). Near the end of his life, Hamilton was tackling the origins of the HIV virus in humans, collecting primate scats in the Congo when he contracted malaria. Incidentally, the rise of HIV in Africa in the early 1990s caused an associated increase in malaria due to weakened human resistance.

Today, the malaria epidemic is huge, affecting half of the world's population--about a million die each year, primarily children in poor areas of Africa and India. There is no vaccine for the disease, and global warming is expected to extend malaria's range back into the paler regions of the world. In January of 2000, just months before Hamilton's demise, the Gates Foundation pledged 6 billion dollars to developing cures for tropical diseases, with malaria as the front-runner (the Bush Administration has since offered up 1.2 billion). This was driven by a lack of interest on the part of private pharmaceuticals to invest in malaria R&D. Hmm, I wonder why the pharms aren't stepping up to the plate? Perhaps when babies with wealthy parents start contracting malaria...

Beyond geographic and economic concerns, the parasite is evolving resistance to the pesticides and medications commonly used to keep it at bay. This is a glaring reminder of why it is so important to understand how evolution works-- parasite populations, having much shorter generation times, can evolve much faster than human populations. We need to be several steps ahead in the coevolutionary game. Religiously-fueled arguments over evolution's legitimacy, whether it should be taught in schools, yada yada, are merely slowing down progress. While we bicker, the parasites are getting better at infecting us. The bottom line is, future generations need to understand evolution better than we do... perhaps even better than both Darwin and Hamilton did.

A-hem, I think I will humbly step off my soap-box for now. For the next X Vials, something a little less preachy... my PLoS pick of the week.

But before I sign off, a big kudos to my sis (the Artista!) for designing the X Vials web banner! It looks perfecto....


For more information on malaria check out:

• The World Health Organization: http://www.who.int/malaria/index.html
• Centers for Disease Control and Prevention: http://www.cdc.gov/malaria/cdcactivities/research.htm
• National Geographic Article: http://www7.nationalgeographic.com/ngm/0707/feature1/