英语翻译NASA’smethodicalapproachtotheexplorationofMarshasnotyetansweredthequestionsofwhetherbiologicallifeformseveremergedonMarsandwhether,[presumingsuchlifeformsleftfossiltracestobeginwith],thosetracesstille

Question

英语翻译
NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars and whether,[presuming such life forms left fossil traces to begin with],those traces still exist in some moist recesses of the cold and arid planet.
主要是begin with的意思不太明白?难道是“假设这种生命形态留下了化石线索以供人们探索”?

Answer 1

NASA（美国航空航天局）探测火星的系统方法尚未解决如下问题,一是火星上曾经有没有（过）生命形式,二是（首先假设这些生命形式曾留下化石之类的蛛丝马迹）,这些遗迹在这个阴冷干燥、贫瘠荒芜的星球上某些潮湿之处如今是否依然存在.
to begin with,不定式置于句尾,亦作插入语,译为：首先
供参