n yourpersonal ancestry. Consider t t for 3.8 billion years, a period of time older tains and rivers and oceans, every one of your forebears on bottractive enougo find a mate, o reproduce, and sufficiently blessed by fateand circumstances to live long enougo do so. Not one of your pertinent ancestors randed, stuck fast, untimely ed from its lifes quest of delivering a tiny cic material to tpartner at t moment in order to perpetuate tarycombinations t could result-eventually, astoundingly, and all too briefly-in you.

    t  icular  from tall to ttle of t someturned into us, and alsosome of s a great deal to cover, of course,  isnt really. Itcouldnt be. But ime  is.

    My oarting point, for s rated science book t I ext ered, unloved, grimly y-but near t it ration t justcaptivated me: a cuta  intot ing about a quarter ofits bulk.

    Its o believe t time ionbefore, but evidently I  for I clearly remember being transfixed. I suspect, in y,my initial interest e image of streams of unsuspecting eastboundmotorists in tates plunging over tral America and t gradually my attention did turnin a more sco tific import of tion t ted of discrete layers, ending in ter  as to tion, and I remembert;?quot;I didnt doubt tness of tion for an instant-I still tend to trust ts of scientists in trust tion-but I couldnt for t  no eye rate, could look like and be made of. to me t  amiracle. t ion h science ever since.

    Excited, I took t nig before dinner-an action t I expectprompted my