Mitchell Sogin, Evolutionary Biologist: Proof of the First Animal

As an evolutionary biologist, 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.