An ISU professor has lent his expertise to help scientists discover what makes humans different from chimpanzees, human beings’ closest living evolutionary relatives.

Xiaoqiu Huang, associate professor in computer science, provided scientists at Washington University’s School of Medicine’s Genome Sequencing Center in St. Louis, Mo., the Broad Institute of MIT and Harvard in Cambridge, Mass., with computer software to help reveal the key differences between the human and chimpanzee genomes. Huang spent eight months during 2003 working on a program to assemble the chimpanzee genome sequence so scientists can easily compare it with the human sequence.

“Scientists have always known the genes were similar, but chimps are not so advanced,” Huang said. “The goal of the project is see the extent of the difference in brain development.”

By assembling the sequence, scientists discovered that 98 percent of chimpanzee gene sequence is similar to that of the human gene sequence, but there are obvious differences between the species’ brain development.

Huang said his work will help identify what genes are involved in human brain development that make humans more genetically advanced.

Comparing genomes will help identify the molecular basis for specific human traits, such as enlarged brains and complex languages. Comparison may also reveal the origin of many human diseases, said Shiaw-Pyng Yang, research assistant professor of genetics at Washington University’s Genome Sequencing Center.

“This study focuses on the differences at the molecular level that could give insight on why humans suffer from some diseases that chimpanzees do not,” he said. “If we see how the genes differ, that could lead to biomedical breakthroughs.”

According to the draft assembly based on Huang’s software, published Sept. 1 in Nature International Weekly Journal of Science, scientists used the software to generate a catalogue of genetic differences that have accumulated since humans and chimpanzees evolved from a common ancestor.

“This program will help us know the difference at a molecular level,” he said. “With the DNA sequences, scientists are able to make further advancements.”