Charles Darwin, one of the first evolutionary biologists, was born 202 years ago. Students and faculty chewed to his success and birthday with celebratory cake Wednesday, three days before his actual birthday.

The "Tree of Life" has been a biological metaphor and useful tool in evolution and genealogy for scientists as far back as Darwin. Courtesy Photo.

The celebration was a precursor to a timely discussion called “The Tree of Life: A Genealogy of Earth’s Organisms,” where students and faculty explored the metaphor of a branching tree in genealogy, a description of life found in Darwin’s research.

The talk was part of Science Café, a series of discussions hosted in the Robert E. Kennedy Library on art and science topics between different disciplines and facilitated by an expert, this time by Kirsten Fisher, assistant professor of biological sciences at California State University, Los Angeles. She spoke about the significance of the tree of life, how to interpret it, common misconceptions and how the tree is used.

The tree of life metaphor became popular to display concepts like ancestry and genealogy because of the way figurative “parent” and “offspring” relationships are pictorially drawn. By visually representing these relationships with lines, the results become reminiscent of a tree. They’re very useful in showing recency and common ancestry, Fisher said.

She began the lecture by explaining the tree’s origin, which dates back thousands of years.

“It was a common motif in ancient mythology to describe the knowledge and interface between divinity and man,” Fisher said.

Now, the tree of life is increasingly important for the sciences, Fisher said. Scientists rely on it for an evolutionary framework, and it displays our understanding of biological diversity. It’s also used in more applied sciences, in areas such as forensics, conservation, agriculture, medicine and pharmacology.

But trees are more complex than most people think, Fisher said.

“We assume they’re easy to interpret, but they’re not intuitive at all; they’re not free of biases,” Fisher said.

This difficulty is in part due to the way trees are drawn or constructed; they can be confusing and reinforce common misconceptions about evolution.

One misconception is that evolution is working toward a goal indicated by the increasing complexity of the tree (lots of branches, busy at the top). This implies evolution is progressing toward perfection.

Another falsity is organisms are living at the same time as their ancestors, which Fisher said is impossible if they have been evolving for the same amount of time and come from a common ancestor.

A prime example of this is humans have evolved from monkeys. This can’t be true because they have evolved from the same common ancestor and for the same amount of time, and it would be impossible to be coexist, Fisher said.

She proposed solutions to avoid these misconceptions: not giving humans their own spot on the tree of life and avoid presenting the tips of the tree in the order people expect to see them.

“It would be more accurate to have them at the same level since we all coexist today,” Fisher said.

Fisher was invited to speak by Cynthia Perrine, the Science Café coordinator and former colleague of Fisher’s, to discuss the tree of life.

Attendance at the café varies from event to event, ranging from 15 to 100, depending on the topic and peoples’ schedules, but the informality of the talks allows people to come even after they start or leave before they finish, said Eileen Akin, programs specialist for the library.

“It’s really not a lecture,” Akin said. “It’s a conversation. It’s a give and take; questions and comments can happen throughout.”

Perrine wants the Science Café discussions to encourage the application of science in every day life.

“We’re promoting science literacy and using scientific principles to communicate and be able to converse — as well as reading and writing coherently — and make good decisions accordingly,” Perrine said.

The café is part of an international movement called Café Scientifique that originally started in Europe, Akin said.

“It’s for people interested in a casual, informal way to talk about science related topics, led by an expert or two, but open to the public,” she said.

The next Science Café talk, “Underwater Exploration: Discovering ancient shipwrecks and cargoes” with featured lecturer, Timothy Gambin, will be Feb. 16 at 3:30 p.m.

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