How can the practice of tillage be harmful to the overall environment? a. it can impact waterways through sedimentation and pollution. b. it is harmful to the soil that is tilled. c. tillage decreases overall crop productivity. d. all of the above

A. review what is evolution? b. apply concepts what ideas were changing in the scientific community at the time of darwin's travels? how might those new ideas have influenced darwin? 7. a. review what three kinds of variations among organisms did darwin observe during the voyage of the beagle? b. infer darwin found fossils of many organisms that did not resemble any living species. how might this finding have affected his understanding of life's diversity? apply the big idea: interdependence in nature 8. you have learned that both biotic and abiotic factors affect ecosystems. give some examples of each, and explain how biotic and abiotic factors could have affected the tortoises that darwin observed on the galápagos islands.