Endless mysteries lurk in the depths of space. To pare the list down to eight—now, there’s a challenge

Tissue graveyard:  When epithelial cells (common in body tissues) die, how are they disposed of?  A kind of burial at sea takes place automatically as neighboring cells squeeze out the bad cell, Current Biology said (Current Biology, Volume 22, Issue 11, R453-R455, 5 June 2012, 10.1016/j.cub.2012.04.036).  It’s called “crowding-induced live cell extrusion.”  This is important because “To maintain a functional and harmonious epithelial society, the number and quality of cells need to be tightly controlled,” Katoh and Fujita emphasized.

Immigration policy:  “We are not alone,” Michael Balter wrote, but he was not discussing SETI or aliens, he was introducing a special feature in Science last week about the “microbiome,” the set of microbes that travel with us everywhere we go.  “Our bodies, inside and out, are teeming with trillions of microbes. Most of them are our friends, helping us to digest food, strengthen our immune systems, and keep dangerous enemy pathogens from invading our tissues and organs.”  Needless to say, if our own cells did not keep tight regulation of these alien cells, we would be in constant danger.  In his introductory article (Science 8 June 2012), Balter wrote, “Evidence is building that this resident community of microbes, called the microbiome, plays a major role in health and disease.”

• Immigration policy:  “We are not alone,” Michael Balter wrote, but he was not discussing SETI or aliens, he was introducing a special feature in Science last week about the “microbiome,” the set of microbes that travel with us everywhere we go.  “Our bodies, inside and out, are teeming with trillions of microbes. Most of them are our friends, helping us to digest food, strengthen our immune systems, and keep dangerous enemy pathogens from invading our tissues and organs.”  Needless to say, if our own cells did not keep tight regulation of these alien cells, we would be in constant danger.  In his introductory article (Science 8 June 2012), Balter wrote, “Evidence is building that this resident community of microbes, called the microbiome, plays a major role in health and disease.”

We look out our eyeballs like a captain looks out the window of a cruise ship, thinking we are in control of this large vessel we inhabit.  But actually, just like the captain of the ship, we are clueless as to what is really going on in the hull.  In a large cruise ship with hundreds of employees and thousands of guests, little emergencies happen all the time: a fire in the kitchen, a suspicious character in the wrong place, anomalies in the engine room.  If the captain had to know every incident, he would be distracted from steering, for one thing, and wouldn’t know what to do about most problems anyway. 

• We look out our eyeballs like a captain looks out the window of a cruise ship, thinking we are in control of this large vessel we inhabit.  But actually, just like the captain of the ship, we are clueless as to what is really going on in the hull.  In a large cruise ship with hundreds of employees and thousands of guests, little emergencies happen all the time: a fire in the kitchen, a suspicious character in the wrong place, anomalies in the engine room.  If the captain had to know every incident, he would be distracted from steering, for one thing, and wouldn’t know what to do about most problems anyway. 

Fortunately, each department on the ship has policies and procedures for handling just about every contingency.  The captain smiles, hands on the wheel, confident the ship is under control.  In our bodies, things are far more precarious.  We are beset daily by broken DNA strands hit by cosmic rays or ionizing radiation, unhealthy food materials, improperly folded proteins, and a host of bacteria and viruses that vastly outnumber our own cells.  As with the cruise ship, there are built-in policies and procedures for handling most of these situations that operate without our conscious knowledge or control.

• Fortunately, each department on the ship has policies and procedures for handling just about every contingency.  The captain smiles, hands on the wheel, confident the ship is under control.  In our bodies, things are far more precarious.  We are beset daily by broken DNA strands hit by cosmic rays or ionizing radiation, unhealthy food materials, improperly folded proteins, and a host of bacteria and viruses that vastly outnumber our own cells.  As with the cruise ship, there are built-in policies and procedures for handling most of these situations that operate without our conscious knowledge or control.

One biology professor was fond of remarking, “The amazing thing is not that we get sick.  The amazing thing is that we are ever well.”  Are you having a nice day today?  Are you basically healthy?  Count your blessings.  You have so many trillion helpers inside of you, you could not possibly know what they do or why.  Not even our leading scientists have a grasp on all the relationships, signals and pathways involved.  We know a little about white blood cells that patrol our internal highways.  We know a little about DNA damage repair. 

• One biology professor was fond of remarking, “The amazing thing is not that we get sick.  The amazing thing is that we are ever well.”  Are you having a nice day today?  Are you basically healthy?  Count your blessings.  You have so many trillion helpers inside of you, you could not possibly know what they do or why.  Not even our leading scientists have a grasp on all the relationships, signals and pathways involved.  We know a little about white blood cells that patrol our internal highways.  We know a little about DNA damage repair.