Humans have a ''disproportionately huge effect'' on the other species of vertebrates that share Earth's surface with us, causing more than 25 percent of the deaths among an array of species all over the globe, according to a recently published study.A team of scientists from the SUNY College of Environmental Science and Forestry (ESF) in Syracuse, New York, and the U.S. Department of Agriculture analyzed the deaths of 42,755 animals that were reported in 1,114 published studies. They found that 28 percent of the animals' deaths were directly caused by humans.