A year to celebrate the achievements of Galileo and Darwin

This is a year of celebrations for the world’s scientists. Biologists remember Charles Darwin, whose 200th birthday falls within this month. November marks the 150th anniversary of his seminal book “On the Origin of Species.” Astronomers honor Galileo, who made the first telescopic observations of celestial objects 400 years ago this autumn.

But while scientists whoop it up for their historic heroes, they want fellow citizens of the world to join the festivities. The aim, they say, is to share the wonder and insights of their science with all humanity.

Astronomers kicked off the International Year of Astronomy last month with a symposium in Paris. The “year” includes events organized around the world, such as well-illustrated presentations and lots of eyeball-to-telescope public viewing and Internet-accessible cosmic images. The logo branding these events proclaims “The Universe: Yours to Discover.” If you want to join the fun and download that logo explore the website at astronomy2009.org.

There will likewise be many ways to celebrate Darwin’s bicentennial. The high point will be a five-day festival of science in July at the University of Cambridge in England. When a similar three-day science festival was held there at Darwin’s centenary in 1909, you had to be there to enjoy it. But thanks to the Internet, much of this year’s festival can be shared globally. Check out the website at www.darwin2009.cam.ac.uk.

All this outreach is aimed at helping to increase public understanding of science. The American Association for the Advancement of Science, which supports the Cambridge festival, emphasized that point in its journal Science saying: “In today’s society where science is broadly integrated in enhancing human welfare such a broad public understanding is required of not just new discoveries, but of their deep and enduring roots.”

Darwin’s theory of evolution envisions useful new traits arising naturally within a species giving the individuals so favored an edge for survival. This theory of natural selection or survival of the fittest remains a guiding principle in biology. But Darwin thought the changes arose only within a given species. He envisioned life’s evolution as a tree starting from a single common ancestor and branching again and again as changes arising within existing species gave rise to more and more new species.

Modern DNA studies indicate that species can acquire new traits by sharing genes with each other. This makes life’s evolution look more like a web of interacting strands than an ever branching tree. The question of what metaphor to use for life’s evolution is at the cutting edge of biological research today. Darwin’s key idea of natural selection remains useful but has itself evolved.

Scientists are keen to share their understanding of the thought processes by which yesterday’s science leads to a better understanding of nature today. In an editorial in the journal Science, cosmologist Martin Rees at Britain’s Cambridge University put it this way: “Science is the one truly global culture, and it is surely a cultural deprivation to be unaware of the chain of events ... whereby, on at least one planet, Darwinian selection led to the emergence of creatures able to ponder their origins.”