Genes count no big deal

Answer: It's not really how many genes but how they're regulated or expressed during development, says Hopi Hoekstra of the University of California-San Diego. In fact, we have scarcely more genes than worms and fleas and far fewer than salamanders. Secondly, "junk DNA" is something of a misnomer; there is clear evidence that these regions not coding for proteins are full of gene-regulatory elements. "In other words, some non-coding DNA regions have function, even if termed 'junk,' and these control gene expression. Finally, there's simply no correlation between genome size and organismal complexity."

As to our being "lords of the realm," adds Stanford geneticist Matthew P. Scott, while it's true our brain's cortex sets us apart in language and thinking, in other regards many species can outdo us — birds flying, bats navigating by sonar, bears smelling food miles away. These abilities arise often from changes in "control elements" rather than sheer numbers of genes. Plus, "I think that insects and some microbes might view our lordly status as temporary at best . . . at least it seems that way when I try to keep flies and ants out of my kitchen."

Question: So many wonderful ways to look at a kicking, crying, arm-waving newborn baby. For instance, how much cosmic energy does the little darling represent?

Answer: E = mc^2 — that's Einstein's most famous equation. The E stands for the energy bound up in ordinary amounts of mass, the c represents the speed of light, or 186,000 miles (300,000 kms) per second! Squaring the speed of light, you get a sense of how even a little mass — like the "stuff" in a newborn — is worth a lot of energy, says Nigel Calder in "Magic Universe."

Say the babe weighs 3 kilograms: A hurricane would have to rage for an hour or a large power station run for a year to match the cosmic energy in that bouncy body. "If the parents had to pay for the energy, it would cost them a billion dollars."

Question: Empathy — being able to feel for another person — is akin to sympathy or compassion. Can this subtle capacity be detected by an MRI?

Answer: In an fMRI brain scan, empathy resembles a sort of minor constellation, with clusters of encephalic stars glowing in the cosmos of an otherwise dark brain, says Lydialyle Gibson in "University of Chicago Magazine." This signature network of cells lights up not only when a subject witnesses someone else in pain but also when the subject experiences pain firsthand, though the constellations are somewhat distinct. "The brain knows the difference, and that is important."