LU alum Arnosti discusses new progress in genetics

Chris Chan

On Monday, May 14, Professor David Arnosti delivered a Science Hall Colloquium lecture entitled “The Human Genome Project: Lewis and Clark, or the Closing of a Frontier?” to a packed auditorium.Arnosti is a Lawrence graduate (‘82) who teaches in the biochemistry department at Michigan State University. He also directs a focus group on gene experiments and disease. In his lecture, Arnosti described the recent scientific achievement wherein the human genome was successfully mapped, and the implications that this has for the future of humanity.

Why are Lewis and Clark mentioned in a lecture about the human genome? When Lewis and Clark explored the western United States, they mapped new terrain and amassed a vast and eclectic quantity of information. The journey of Lewis and Clark is a metaphor for the odyssey of research and experimentation performed by biochemists that seek to understand the mysteries of genetics.

At the beginning of the lecture, Arnosti asked four questions about the nature of the human genome project. These questions asked how the genome was mapped, what exactly was found, where scientists will go from here, and what this newfound information means for humans.

Before answering these questions, Arnosti explained what a gene is. One definition, from a geneticist’s perspective, states that “a gene is something that a person inherits that produces a noticeable trait.” A genome is composed of all of an organism’s genes and the rest of the DNA sequence.

Mapping the human genome took decades of research and a great deal of money, explained Arnosti. The human genome project was a very publicly funded effort, demanding a great deal of tax money throughout the world.

Arnosti went on to explain how technology has improved as well. For instance, DNA patterns, once simply black bands on plastic, have become color-coded, making them easier to read. Arnosti explained how scientists worked up to mapping the human genome, analyzing first the bacterial genome, then the genome of a fruit fly, then a plant, and then the human genome.

After the genome was mapped, explained Arnosti, it was discovered that DNA sequences between human individuals are surprisingly similar. Human genomes only differ about one part per 13,000. The human genome differs from the chimpanzee by only one part per hundred. Humans have 35,000 genes, compared with 4,000 genes for the E. coli bacteria, 6,000 genes for yeast, and a whopping 50,000 genes for rice. Arnosti hastened to add, “the complexity of an organism is often NOT related to the overall size of the genome.”

Despite this progress, Arnosti says there is still much work to be done. Scientists Andrew Murray and Debora Marks declared that “genome sequencing revealed surprisingly little about the cell cycle.” Arnosti states that there is still a great deal of experimentation and research to perform in the field of genetics. Only 90% of the human genome has been mapped, and there are nearly 100,000 gaps in the record. Even now, there is still a great deal of guesswork about the structure of most human genes.

Arnosti mentioned that a great number of philosophical questions have been raised over the genome project. Thinker Alex Mauron once asked, “Is the genome the secular equivalent of the soul?” In addition, the answers provided by the mapping of the human genome do not answer all the questions about the role of humans in the universe. Arnosti concluded his lecture by holding up a T-shirt emblazoned with the words, “DNA is life—the rest is just details.”