Please Explain (The Leonard Lopate Show)

DNA testing has been in the news lately, thanks to the raid on the FLDS compound in Eldorado, Texas where authorities don’t know which children belong to which parents. We find out what DNA is, how it defines us, and how DNA testing works. Dr. Timothy Bestor is Professor of Genetics and Development at the College of Physicians and Surgeons at Columbia University Medical Center. Dr. Brian McCabe is Assistant Professor of Physiology and Cellular Biophysics at the College of Physicians and Surgeons at Columbia.

It’s virtually impossible to get through the day without using plastic, but it’s only been widely available to consumers for about 100 years. We find out what plastic is, why it’s so useful, and whether we should be concerned about its widespread use. Dr. Mark Michalovic is Educational Consultant with the Chemical Heritage Foundation. Robert Malloy of UMass Lowell is a researcher in the areas of plastics product design, polymer processing, recycling of thermoplastics.

Find out about the different types of foreclosures, the legal process by which a property can be seized, how the real estate collapse has is affecting New Yorkers, and the industry that is thriving on America’s housing woes. Michael MacKenzie is US Markets Correspondent for the Financial Times. Josh Zinner is the co-director of the Neighborhood Economic Development Advocacy Project; he previously served as long-time Director of the Foreclosure Prevention Project at South Brooklyn Legal Services.

Get out your tissues - Please Explain is all about crying. What are tears made of? How did crying evolve? Is it a uniquely human phenomenon? Does it have health benefits? Vassar psychology professor Randy Cornelius has been developing an evolutionary theory of weeping that focuses on tears. Tom Lutz, director of the MFA in Creative Writing and Writing for Performance program at UC-Riverside Palm Desert, is the author of Crying: The Natural and Cultural History of Tears.

We look into how children play games of make believe, and whether kids’ imaginations have changed along with trends in technology and education. Dr. Susan Linn is Associate Director of the Media Center of the Judge Baker Children's Center, Instructor in Psychiatry at Harvard Medical School, and the author of most recently The Case For Make-Believe: Saving Play in Our Commercialized World. Dr. Elizabeth Goodenough teaches at the University of Michigan Residence College and is the author of most recently Under Fire: Childhood in the Shadow of War.

Weigh in: What games of make believe do your children play? Are they different from what you remember playing when you were a kid?

NPR says that its mission is to present "fair, accurate and comprehensive information and selected cultural expressions for the benefit of, and at the service of our democracy." That's easier said than done.

Find out how NPR shapes its news and political coverage, who makes judgment calls on a daily basis, and what happens when problems arise. Alicia Shepard is NPR Ombudsman.

Weigh in: What are your comments and/or complaints about NPR's coverage of news and politics? What would you like to hear more or less of?

Find out about two senses we often take for granted - balance and proprioception (the sense that indicates body movement and placement).

Parkways are a kind of road common in the New York City area, but more rare in the rest of the USA. Find out what parkways are, and how they fit in to the American transportation system. Dr. Timothy Davis is Lead Historian for Park Historic Structures & Cultural Landscapes Program at the U.S. National Park Service.

"Carbon footprint" has become a catchphrase in the last year or two. We find out just what a carbon footprint is, how it’s calculated, and how much it matters. Mark Z. Jacobson is Professor in the Department of Civil and Environmental Engineering at Stanford University and Catherine S. Norman is Assistant Professor in the Department of Geography and Environmental Engineering at Johns Hopkins University.

Weigh in: Do you have any idea what your carbon footprint is? Would knowing your carbon footprint make you change your daily habits?

We look into the fascinating lives of ants. For example: some ant species can form floating rafts in order to survive floods. Another species, weaver ants, build nests in trees by sewing leaves together.

Brian L. Fisher is the Chairman of Entomology at the California Academy of Sciences and creator of antweb.org. He specializes in the large-scale discovery, description, and naming of African and Malagasy ants. Dr. John T. Longino of Evergreen State College specializes in neotropical myrmecology.