This video-based course probes the question “Are we alone?” Unlike SETI scientists, Mars rovers and planet-hunting astronomers, we take a biological approach and ask: “How did WE get here?” Like salmon swimming upriver to the pond where they were born, we are led upstream from whence we came. We take a pilgrimage into the past to the origin of life 4 billion years ago. During this evolutionary odyssey with astrobiologist Charley Lineweaver, we ask: Who is “we”? Why did our brains get so big? How did life get started? Are viruses alive? What is life? Answers to these questions may help us get from How DID life start? to How DOES life start?

Are we alone? seems like a simple question. But, who is “we”? What does it mean to be alone? Alone where?… in our stellar neighbourhood? the galaxy? the entire universe? Is “Are we alone?” an important question? Have humans always asked this question? How have our ideas about extraterrestrials changed with time? The range of “expert” answers to these questions is enormous.

We lost our tails about 20 million years ago. We lost our small brains a few million years ago. Humans are unique, just like every other species. The idea that chimps are our cousins NOT our ancestors is emphasized again and again – maybe someday someone will understand this.

A lot happened to us over the past 0.5 billion years. We became deuterostomes with heads, backbones, legs, hair and nipples. This post-Cambrian period contains only about 10% of our evolution but is the focus of ~90% of all biologists. Astrobiological and microbiological perspectives are needed to cure this vertebrate-centrism.

This week focuses on endosymbiosis, the origin of the eukaryotic cell, the origin of multicellularity and the tragic separation of somatic cells from the germline. Are sex and death so fundamentally linked that we should expect them to evolve on other planets?

Phylogenetic trees help identify the most fundamental features of the last universal common ancestor of all cellular life on Earth. How many domains of life are there? Maybe a viral phylogeny can be grafted as a root onto the tree of cellular life? Did viruses, viroids or ribozymes play a role in the origin of life? Was the RNA world a viral world? The controversial claim is made that there is no minimal amount of information or minimal size to “life”.

When and where did life originate? What is life? Can evolutionary convergence help us figure out what life beyond Earth is like? 20 experts shine some light onto these dark mysteries.

Most physicists think it is better to be smart than stupid. If they are correct, we should expect aliens with technological intelligence. But if so, where is everybody? Most biologists are not convinced that human-like intelligence is a convergent feature of evolution. Paleontology supports the biologists.

Different sciences take different approaches to try to answer the question: Are We Alone? Here we present short and long versions of interviews with some of the world’s leading experts in geology, planet formation and planetary atmospheres — from planet-hunting astronomers to universe-quantifying cosmologists.

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Are we alone in the universe?

About Charley Lineweaver

Charles H. Lineweaver is an honorary associate professor at the Research School of Astronomy and Astrophysics and Research School of Earth Science at the Australian National University. His research areas include exoplanetology (the statistical analysis of exoplanets and their habitability), astrobiology (using our new knowledge of cosmology to constrain life in the Universe) and cancer (a new atavistic model). Charley earned a BA in history from the State University of New York at Binghamton, an MA in English from Brown University, a BSc in physics from Ludwig Maximillian’s University in Munich, and a PhD in physics at the University of California, Berkeley in 1994. He is the son of a high school biology teacher and has lived in or travelled through 82 countries, has spoken four languages semi-fluently at one time or another, and was a semi-professional soccer player in Germany.