Cristina Diaz describes her work as a taxonomist. She dives in Indonesia to study her favorite animal—the sponge. Conducting an experiment to see how fast a sponge filters, she injects a colored dye into the water. The results amaze her. She takes a sample to the lab to observe the cells under a microscope.
As an evolutionary biologist, Mitchell Sogin searched the genetic codes of many organisms to discover which gave rise to all the others. He investigated the genes of the sponge starting with gene sequencing to find the genetic blueprint of the sponge so he could compare it to those of other organisms. Sogin built a family tree based on comparing DNA sequences of various genes and confirmed what had been theorized: sponges are the first animal.