House and Senate intelligence committees will ask that question of FBI officials during closed hearings Tuesday about the Boston Marathon bombing. They will want to know if any red flags popped up when Tamerlan Tsarnaev traveled to Russia in 2011-12.
Martin Richard, the 8-year-old boy killed in the Boston Marathon bomb attack, once held a sign that said 'peace' and 'no more hurting people.' Research finds a pattern of lessening violence as human history moves forward.
Once thought to be extinct, the coelacanth (through its DNA) is aiding scientists in their growing understanding of evolution. When inserted into mice, the fish's DNA causes the mammals to grow limbs. In the fish the same DNA codes for fins, not limbs.