MicroScoop

I recently finished reading Carl Zimmer’s Parasite Rex. It was a fantastic and easy read. It gave me a newfound appreciation for parasites.

One of the more fascinating concepts Zimmer discusses is how parasitism affects human evolution. When a parasite infects a host, it imposes pressures on the host to evolve in order to survive. He uses Plasmodium falciparum, the parasite that causes malaria, as an example. Plasmodium species has been around for ages. The first use of cinchona (which contains chemicals related to quinine) to treat malaria was recorded in 1640, but the native Indians of Peru and Ecuador have been using it even before that. (Fun fact: tonic water contains quinine, which was used by the British army to prevent malaria in India. Tonic water is particularly bitter so in order to make it more palatable, the soldiers mixed tonic water with gin - and that is how the cocktail was invented!) Plasmodium species ends its life cycle in the red blood cells. Invasion of a red blood cell occurs in three stages: contact, attachment, and endocytosis (red blood cell takes in the parasite).

Malaria is endemic to tropical countries. Scientists studying malaria noticed that in these regions, the incidence of a particular disease - sickle cell anemia - is particularly high. Individuals with sickle cell anemia contain mutations in their hemoglobin genes, causing a deformation in their red blood cells (making them look like sickles). Complications include obstruction of capillaries and restriction of blood flow to various organs.

This is where it becomes really cool. Individuals with sickle cell trait only have one copy of the mutated gene. In individuals with sickle cell trait (carrier of one gene) and sickle cell anemia, Plasmodium falciparum is unable to attach to the red blood cell and induce endocytosis. Therefore, it is advantageous to have sickle cell trait and sickle cell anemia in places where malaria is endemic. And just like that, a genetic mutation in the hemoglobin gene is preserved in a population.

Think about it: something that is about 1/100th the size of the finest grain of sand can have such an incredible impact on human evolution. Crazy cool!

Soon after I moved to Sydney, I came across this commencement speech delivered by Robert Krulwich, a science writer for NPR and co-host of WNYC’s Radio Lab, to the Caltech graduating class of 2008. His speech was absolutely inspiring. (I cried - I might have been feeling particularly emotional that day) The first time I heard it, I thought to myself, “He’s damn right!” Science should not be about technical jargon; it should be about a powerful curiosity as to why or how things work. It should be about, as Robert Krulwich put it, “the power to excite, to enthrall, to remind people there’s a deep beauty, a many-leveled beauty in the world.”

I recently revisited his speech and I was inspired to finally write in this blog. On this blog, I will share fascinating bite-sized morsels of science (which will most likely be heavy on the biology). I hope you find these stories palatable and slightly interesting, possibly even exciting and enthralling.

(Please pardon the layout/font/lack of personal information while I get used to this whole blogging thing.)

Once I get more time in my hands, this site will eventually be the home of my thoughts on anything I find interesting.  Check back in a few weeks for an updated look - and maybe even a post!