给这篇文章写个250字左右的summaryFree energy is a universal requirement for life It drives mechanical motion and chemical reactions —which in biology can change a cell or an organism Over the course of Earth hist

The evolution of life on Earth has been shaped by the expansion of free-energy sources available to living organisms. From geochemical energy to sunlight and fire, the harnessing of free energy has had a dramatic impact on the planetary environment over the course of Earth's history. The earliest life forms were autotrophs that harnessed geochemical energy, and the ability to use sunlight evolved later. The advent of oxygenic photosynthesis increased the productivity of early ecosystems, and the emergence of animals triggered a radical shift that transformed the Earth. As Earth is the only life-planet system we currently know of, it is impossible to know how representative it is of life-planet systems in general. However, the framework presented suggests a way to anticipate the paths that such systems might take. While the expansion of free-energy sources has allowed for the diversification of life and the transformation of the planet, it has also led to rising levels of carbon dioxide and other greenhouse gases, increasing pollution, and massive shifts in biogeochemical cycles, the full geological effects of which are still unknown.