它标志着中国人，至少是中国知识分子特别是青年学生意识的觉醒，是1840年以来中国青年知识分子群体第一次全身心地投入，由此揭开了中国历史的新篇章，即中国的政治已不再发、限于职业政治家范围，而扩大到了知识分子阶层特别是青年学生层面，“它”是（  ）        

    Rainforests, it turns out, are not created equal. Take the Amazon rainforest, an area that covers about 7 million square kilometers. But within that huge expanse are all kinds of ecological zones, and some of these zones, says Greg Asner, are a lot more crowded than others.

    “Some forests have many species of trees,” he said, “others have few. Many forests are unique from others in terms of their overall species composition…” And all of these different small areas of forest exist within the giant space that is the Amazon Rainforest.

    So Asner, using the signature technique called airborne laser-guided imaging spectroscopy, began to map these different zones from the air. “By mapping the traits of tropical forests from above,” he explains, “we are, for the first time, able to understand how forest composition varies geographically.”

    The results show up in multicolored maps, with each color representing different kinds of species, different kinds of trees, the different kinds of chemical they are producing and using, and even the amount of biodiversity, the animal and plant species that live within each zone.

    Armed with this information, Asner says decision-makers now have “a first-time way to decide whether any given forest geography is protected well enough or not. If not, then new protections can be put in place to save a given forest from destruction.”

    Asner says the information is a great way for decision-makers to develop a “cost-benefit ratio type analysis.”  Conservation efforts can be expensive, so armed with this information, government leaders can ensure they are making the most of their conservation dollars by focusing on areas that are the most biologically diverse or unique.

    The next step, Asner says, is to take his project global, and to put his eyes even higher in the sky, on orbital satellites. “The technique we developed and applied to map Peru is ready to go global.” Asner said. “We want to put the required instrumentation on an Earth-orbiting satellite, to map the planet every month, which will give the best possible view of how the world's biodiversity is changing, and where to put much needed protections.

青蛙、家燕、小麦个体发育的起点都是受精卵。