Igure s.22, page 25 1 is sphern also possible that life originated in hot springs similar t those found in yellowstone national park 1.5 billion years ago, that dramatically transfo our planet. fossil evidence for the existence of t scopic bact stromatolites, composed of slimy material se ie eme back smal as eria includes distinctively layenedd mats, called earth's first life: prokaryotes regardless of where or how life originated, it is clear that what the journey from "then' to now involved change (figure from the stuly of modern stromatolites like those four canisms, along with trapped sediments (figure 2221 wn abont these an cient fossils comes mainly 22 20. the first known organisms were simple single-cell l shak bas anstrai ure 221a) to s stromatolites ear the figu lke stubby pillins bi eye on earth 22.2 enal ing t he rocks shown here are cambrian-age stromatolites of the hoyt limestone, exposed at lester park, near saratoga springs, new york lant that 22.2 se question 1 using figure 22.3, determine approximately how many years ago these rocks were deposited question 2 what is the name of the group of organisms that likely produced these limestone deposits? question 3 what was the environment like in this part of new york when these rocks were deposited? leng in p