The answer is (A) stabilizing selection. Stabilizing selection favors the average in a population. In this case, babies that are born at a normal body weight, or an average between the two extremes of underweight and large, tend to have more favorable outcomes.
Well... I get the felling I know what question you are trying to ask. Atrial Fibrillation is a type of arrhythmia that interferes with the pumping of blood through the Atrium of the heart. A bundle branch block is an interference of the electrical system through the heart. Non of these are particularly that dangerousso don't worry about dying... Though have someone close by in case you go into Cardiac Arrest.
If your worried about getting a heart attack, that is a blood flow problem which can result from CAD. Don't worry though cause the two other condition do not particularly influence the other.
CAD is circulatory, A fib and branch block are electrical.
The origin of life on Earth is a set of paradoxes. In order for life to have gotten started, there must have been a genetic molecule something like DNA or RNA capable of passing along blueprints for making proteins, the workhorse molecules of life. But modern cells can’t copy DNA and RNA without the help of proteins themselves. To make matters more vexing, none of these molecules can do their jobs without fatty lipids, which provide the membranes that cells need to hold their contents inside. And in yet another chicken-and-egg complication, protein based enzymes, encoded by genetic molecules, are needed to synthesize lipids.
