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2014 Oct 15

Origins Forum - Earth Meets Universe (Caleb Scharf - Columbia University)

4:00pm

Location: 

Haller Hall (Room 102), Geological Museum, 24 Oxford Street

Abstract - 

Finding just one example of a biosphere beyond the solar system would
not only place real constraints on life's cosmic abundance and
origins, but also allow us to place the Earth in proper context. To do
this we need to search for astronomically visible, surface dominant,
living systems. One step towards this is the process of evaluating the
physical and biological environments of a diversity of rocky worlds to
understand their climatological states. Along the way we need to
better constrain the orbital behavior of observed exoplanetary
...

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2014 Sep 17

Origins Forum - Geological Perspectives on the Early Evolution of Eukaryotes (Andrew Knoll- Harvard)

4:00pm

Location: 

Change in location* Haller Hall (Room 100), Geological Museum, 24 Oxford Street

Two of life’s three domains, the Bacteria and Archaea, diversified on the early Archean Earth. The third domain – the Eukarya, or eukaryotes – evolved later, however, at least in part via symbiosis between members of the other great clades.  Eukaryotic organisms radiated in Proterozoic oceans characterized by oxygenated surface waters, but, commonly, anoxia at depth.  Exceptionally preserved fossils of red algae favor crown group emergence more than 1200 million years ago, but older (up to 1600-1800 million years) microfossils record a moderate diversity of stem- or early crown-...

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2014 May 21

Origins Forum - “Climate Dynamics of Condensible-rich Atmospheres” (Raymond T. Pierrehumbert - University of Chicago)

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

Raymond Pierrehumbert
Dept. of the Geophysical Sciences
University of Chicago

In Earth's present climate, the condensible component (water vapor) makes up only a small part of the mass of the atmosphere, so energy transport by condensate is small and the effect of condensation on surface pressure is slight. We refer to this as the dilute condensable case. Climate dynamics for the nondilute case engages a number of entirely novel phenomena, which cannot be treated within conventional terrestrial-type general circulation models.  Nondilute climate dynamics is...

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2014 Apr 23

Origins Forum - "On the Origin of Biomolecular Function: Exploring TNA as a Genetic Polymer in the Chemical Path to Early Life" (John Chaput - Arizona State University)

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

John Chaput
The Biodesign Institute at Arizona State University

Life presumably arose through a series of discrete steps in which chemical systems gave rise to unicellular organisms with DNA genomes and protein enzymes. As we study the path from chemistry to biology, several interesting scientific questions arise that are worthy of experimental investigation...

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2014 Mar 12

Origins Forum - "Hot on the Trail of Warm Planets Orbiting Cool Stars" (John Johnson - Harvard)

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

John Johnson
Department of Astronomy
Harvard University

Just three years ago the prospect of finding temperate, rocky worlds around other stars was still the subject of science fiction: none had been found and reasonable estimates put us years or decades away from such a momentous discovery. All of that has changed very recently on the heels of the extraordinarily successful NASA Kepler mission. By searching for the tiny diminutions of starlight indicative of an eclipsing planet, Kepler has produced thousands of new planet candidates orbiting distant stars. Careful...

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2013 Dec 18

Origins Forum - "Peering into the lives of microbes: Lessons on the limits of life from deep sea microbes”

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

Peter Girguis
Dept. of Organismic & Evolutionary Biology
Harvard University

Microbes are, unquestionably, the most critical members of our biosphere. They exist in every habitat, playing a role in mediating atmospheric and ocean composition and governing elemental cycles in soils and sediments. The last two decades have been a watershed for  microbiology, with major advances in genomic sequencing and other technologies that have fundamentally changed our view of microbial diversity and evolution. However, our understanding of what microbes are ...

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2013 Nov 20

Origins Forum - "The meaning of stromatolites"

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

Tanja Bosak
Dept. of Earth, Atmospheric & Planetary Sciences
Massachusetts Institute of Technology

Mineral precipitation, sedimentation and microbial activity have shaped landscapes in coastal environments for nearly 3.5 billion years, forming stromatolites and other sedimentary structures.  The shapes and textures of these structures may record  evolutionary and chemical changes during the first  80% of Earth's sedimentary history. However, as complex products of physical processes, microbial ...

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2013 Oct 16

Origins Forum - "RNA-Mediated Epigenetics and Extreme Genome Architectures in the Ciliate Oxytricha"

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

Laura Landweber  
Dept. of Ecology & Evolutionary Biology
Princeton University

The unicellular eukaryote Oxytricha trifallax has an extremely dynamic pair of genomes, with massive DNA rearrangements producing a highly fragmented, somatic genome from a germline genome roughly twenty times its sequence complexity. During development, Oxytricha eliminates nearly all its noncoding DNA, including all its transposons, and rearranges the ~225,000 remaining DNA pieces to produce functional genes. In the precursor, germline genome, the scattered segments of different genes...

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2013 Sep 18

Combinatorial Chemistry in the Prebiotic Environment

4:00pm to 5:00pm

Location: 

Geological Museum, Haller Hall (Room 102), 24 Oxford Street

David Deamer
Department of Biomolecular Engineering
University of California, Santa Cruz

The pathway leading to the origin of life presumably included a process by which polymers were synthesized abiotically from simpler compounds on the early Earth, then encapsulated to form protocells. Previous studies have reported that mineral surfaces can concentrate and organize activated mononucleotides, thereby promoting their polymerization into RNA-like molecules. However, a plausible prebiotic activation mechanism has not been established, and minerals cannot form cellular...

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