Searching for Life in the Solar System

Lecture Series: Life In The Universe

Timothy D. Swindle, Professor and Head, Planetary Sciences/Lunar and Planetary Laboratory
When Renaissance scholars figured out that the planets are, like Earth, orbiting the Sun, an immediate assumption was that they are inhabited worlds. In the last 50 years, spacecraft have determined that life on the surfaces of planets and moons in the Solar System is rare – if it exists at all. However, there are places where a search for life in the Solar System may still be fruitful. Although the current surface of Mars is a hostile environment, early Mars may have been much more clement to life. Jupiter's moon Europa is almost certainly barren on the surface, but has an 'ocean' of liquid water underneath a crust of ice, where some terrestrial organisms might be able to thrive. Finally, Saturn's moon Titan would not be suitable for life from Earth, but has rain and seas of liquid hydrocarbons, raising questions about whether life needs liquid water, or just needs some abundant liquid.

Amazing Discoveries: A Billion Earth-like Worlds

Lecture Series: Life In The Universe

Laird M. Close, Professor, Astronomy/Steward Observatory

One of the most fascinating developments in the last two decades is humankind's discovery of alien worlds orbiting stars near our Sun. Since the first such discovery in 1995 there has been a truly exponential growth in the detection of these new planets. Scientists have been puzzled and surprised by the diversity and extravagance of these new extra-solar systems. For example, we now know the most common type of planet is actually missing from our own Solar System. Recently, the space-based NASA Kepler Mission has discovered thousands of new worlds and suggests that one in five Sun-like stars may harbor an Earth-like planet. We will take a grand tour of some of these amazing new worlds, specifically noting where life might already exist, beyond our Solar System. The latest developments and difficulties of direct imaging for life on an exoplanet will be discussed.

Intelligent Life Beyond Earth

Lecture Series: Life In The Universe

Christopher D. Impey, University Distinguished Professor, Astronomy

One question rises above all others when it comes to our place in a vast and ancient Universe, 'Are we alone?' With a billion habitable locations in the Milky Way galaxy, and more than ten billion years for biological experiments to play out, a search for intelligent life beyond Earth is well-motivated. Unfortunately, the single example of life on Earth gives no clear indication of whether intelligence is an inevitable or an extremely rare consequence of biological evolution. The search for extraterrestrial intelligence, or SETI, is more appropriately called the search for extraterrestrial technology. So far, the search for intelligent aliens by their electromagnetic communication has met with half a century of stony silence. It's challenging to define life, and even more difficult to make general definitions of intelligence and technology. We'll look at the premises and assumptions involved in the search, the strategies used, and the profound consequences of making contact.

Time Traveling: What Our Brains Share with Beetle Brains

Lecture Series: The Evolving Brain

Nicholas J. Strausfeld, PhD, Director, Center for Insect Science and Regents’ Professor of Neuroscience

Emerging evidence suggests that distantly related animals such as mice and flies manifest similar behaviors because they have genealogically corresponding brain centers. The view is that a common ancestor had already evolved circuits for behavioral actions, memory of such actions, and their consequences more than half billion years ago. Evidence that those circuits have been inherited through geological time challenges how we as a species relate to animals that we view as wholly different from ourselves. 

A Window into the Brain: Viewed through the Evolution of MRI Technology

Lecture Series: The Evolving Brain

Diego R. Martin, MD, PhD, Chair, Department of Medical Imaging and Professor of Medicine, UA College of Medicine
The evolution of MRI technology and its use to study brain structure and function has revealed much of what we know today about the evolving brain and has revolutionized clinical care. Rich visual content will be used to illustrate the technical elements that have been pieced together over time to form the modern MRI scanner. Each element of MRI technology will be introduced from the historical timeline as the scanner system is built piece-by-piece for the audience. Milestones and personalities will be introduced to add meaning and significance showing the innovative spirit and creativity of this technology’s development.

The Evolution of Modern Neurosurgery: A History of Trial and Error, Success and Failure

Lecture Series: The Evolving Brain

G. Michael Lemole, Jr., MD, Chief, Division of Neurosurgery and Professor of Surgery, UA College of Medicine

The science and art of neurosurgery has advanced dramatically in the past few decades, and yet its history is firmly grounded in a paradigm of surgical trial and error.  Collaborations with allied specialties have made these “trials” safer, but much of what we know of functional brain anatomy comes from disease or iatrogenic perturbations.  This lecture will explore the keen observations and dogged persistence that led to our current state of the art.  We will explore how this surgical knowledge of the brain makes our current practice safer and how future technologies will advance our understanding with less invasive but more meaningful impact.

The Literate Brain

Lecture Series: The Evolving Brain

Pélagie M. Beeson, PhD, Professor and Head of Speech, Language and Hearing Science

Written language represents a relatively recent cultural invention, and unlike the development of spoken language, literacy requires explicit and prolonged instruction. How is this accomplished? Do unique regions of the brain develop in support of reading and spelling, or are these skills dependent upon brain regions involved in other perceptual and cognitive processes? By studying disorders that arise following brain damage in previously literate adults, and by using brain imaging techniques to examine neural activity as healthy individuals engage in reading and spelling, a new understanding of the brain is being revealed. Further clarification comes from rehabilitation research that promotes the return of written language skills and provides a view of the brain’s plasticity.

The Ancestors in Our Brains

Lecture Series: The Evolving Brain

Katalin M. Gothard, MD, PhD, Associate Professor of Physiology, Neurobiology, and the Evelyn F. McKnight Brain Institute

The human brain retains ancestral neural circuits that support behaviors geared toward satisfying basic biological needs. Superimposed on these core circuits are newly evolved structures that specialize in complex computations. These specializations convey flexibility to the brain and the ability to distill information into abstract thought. The ancient molecules and core circuits that make us social and emotional beings interface harmoniously with the newly evolved structures that make us thinkers and inventors of technology. 

More Perfect Than We Think

Lecture Series: The Evolving Brain

William Bialek, PhD, John Archibald Wheeler/Battelle Professor in Physics, Princeton University

From its ability to appreciate beauty, to the reassembly of distant childhood memories, to our almost unthinking ability to respond to the unexpected, is our brain really "doing a good job" at solving the problems we confront as we move through the world? Has evolution granted us a rich inheritance of tools, or saddled us with artifacts of a distant past, limiting our ability to solve new problems? Many other animals, from insects to our fellow primates, do many equally remarkable things, but several examples will be presented allowing us to see how the human brain solves problems in an essentially perfect way — no machine operating under the same physical constraints could do better. Examining what is common among the problems that the brain is good at solving begins to suggest a more general principle that may be at work.

Are Genes the Software of Life?

Lecture Series: Genomics Now

Fernando D. Martinez, MD, Director, BIO5 Institute; Director, Arizona Respiratory Center; Swift-McNear Professor of Pediatrics and Regents' Professor, The University of Arizona

The last 20 years have been marked by an astonishing growth in our knowledge about the molecules that make up living things. And among those molecules, none has attracted more attention than DNA. The DNA code of hundreds of life forms has been sequenced, and this code contains not only information needed to assemble all proteins; a myriad of bit and pieces of DNA are also involved in controlling when proteins are built and destroyed. It is thus not surprising that DNA has been called the software of life, but the metaphor breaks down when we look more closely. Contrary to any reputable software, small, random "errors" are introduced in the code each time DNA is copied in order to be transmitted to the next generation. Most often, these changes have no effect whatsoever. Almost all the remaining changes are deleterious and are most likely the cause of the many diseases that affect many human beings at some point in their lives. But a small portion of these random "errors" allow those who carry them to better adapt to the environment in which they live. And the fast and slow accumulation of those favorable "errors" is what ultimately gave rise to the immensely successful history of life in the planet. Two indispensable conclusions arise: first, disease is often caused by the same mechanism, random mutation, that allowed us to become conscious beings and, therefore, those of us who are healthy and can pursue happiness have a basic biological and ethical debt towards those who are not; second, the massive changes that we are introducing into the environment are making many of us sick simply because our ancestors never saw them and thus, never "adopted the right genes" for them. Contrary to all other species that ever existed, therefore, we are increasingly putting our future as a species in our own hands.