Renowned scientist and writer Stephen J. Gould last night condemned human arrogance about evolution before a packed audience in Cook Auditorium.
A zoology and geology professor at Harvard University, Gould has received numerous honorary degrees as well as literary and academic medals and awards for his books, which number more than 15.
Gould spoke about the public's bias toward a linear view of evolution -- one whose changes favor more complex beings. He also argued all biological ages have been part of "the age of bacteria."
Gould began his lecture, titled "The Improbability of Human Evolution in the Age of Bacteria," by condemning what he called the "human-centric" view of nature and evolution.
"We are storytelling creatures," Gould said. "We like to tell a story of evolution and history in terms of us and advancing towards us."
He demonstrated the public's bias by describing two icons of evolution that are widely seen in the public -- the pop culture icon and the high culture icon.
As an example of the pop culture icon, Gould displayed several slides of posters and advertisements, which used the traditional monkey to erect man evolution motif.
Gould said there was a "universality and ubiquity to the evolution parody" that people see across the globe.
As examples of high culture icons, Gould showed slides of artists' impressions of evolution.
He showed how at each level of evolution, only the most complex organism was depicted in the artist's painting. Early slides showed invertebrates only while later slides depicted dinosaurs in water without invertebrates or fish present.
He said these artists illustrated the view that once life evolved to a more complex level, humans ignored the less complex.
Nature does not tell a story in a linear fashion and the history of life should not be the history of the most complex organism, Gould said.
Gould said another public bias, which is "as old as philosophical tradition," is the inability to consider variations in species properly.
"Darwin said variation is not only a device, it is the only reality we have," Gould said.
He said it is a mistake to simply trace an average trait of a species in order to analyze its evolutionary history and used baseball as an example of such an error.
Gould analyzed baseball batting averages for the audience to determine why there have been no averages of more than .400 for an individual player since 1930 while the overall batting average remained constant.
The mistake most baseball fans made was in assuming that because the average was lower than .400, there was something wrong with hitting after 1930, Gould said.
The reason no batters hit more than .400 after 1930 was because natural selection among baseball players led to better pitchers and better batters which created a narrower range of hitting averages closer to the overall average, he said.
Gould argued that the same erroneous assumptions exist regarding complexity in species. He said in the history of life, the majority of life forms will be bacterial, and only the statistical extremes will be complex organisms like humans.
He said this era should not be the age of humans, mammals or insects, but rather the age of bacteria. He pointed out that bacteria comprise the largest proportion of life on earth.
Gould demonstrated the randomness of natural selection and evolution by showing the audience slides of various extinct species that looked extremely well adjusted for their environments.
Gould argued that all organisms were merely handed "tickets in the biggest lottery ever played. If you rewound the tape and redistributed tickets it would be a different world without sentient beings."
He was invited to speak as part of the Class of 1930 Fellowship, a program established by the Rockefeller Center for the Social Sciences to bring distinguished men and women to Dartmouth for brief visits.
