A spark from a lightning bolt, interstellar dust, or a subsea volcano could have triggered the very first life on Earth.
But what happened next? Life can exist without oxygen, but without plentiful nitrogen to build genes – essential to viruses, bacteria and all other organisms – life on the early Earth would have been scarce. (more…)
New study up-ends conventional wisdom
Phytoplankton—tiny, photosynthetic organisms—are essential to life on Earth, supplying us with roughly half the oxygen we breathe. Like all other life forms, phytoplankton require the element phosphorus to carry out critical cellular activity, but in some parts of the world’s ocean, P is in limited supply. How do phytoplankton survive when phosphorus is difficult to find? (more…)
Stanford, CA — Photosynthesis provides fixed carbon and energy for nearly all life on Earth, yet many aspects of this fascinating process remain mysterious. For example, little is known about how it is regulated in response to changes in light intensity. More fundamentally, we do not know the full list of the parts of the molecular machines that perform photosynthesis in any organism.
A type of single-cell green algae called Chlamydomonas reinhardtii is a leading subject for photosynthesis research. Despite its importance in the research world, few tools are available for characterizing the functions of its genes. (more…)
The idea of everyone in a community pitching in is so universal that even bacteria have a system to prevent the layabouts of their kind from enjoying the fruit of others’ hard work, Princeton University researchers have discovered.
Groups of the bacteria Vibrio cholerae deny loafers their unjust desserts by keeping the food generated by the community’s productive members away from V. cholerae that attempt to live on others’ leftover nutrients, the researchers report in the journal Current Biology. The researchers found that individual bacteria produce a thick coating around themselves to prevent nutrients from drifting over to the undeserving. Alternatively, the natural flow of fluids over the surface of bacterial communities can wash away excess food before the freeloaders can indulge. (more…)
Pollination, essential to much of life on earth, requires the explosive death of the male pollen tube in the female ovule. In new research, Brown University scientists describe the genetic and regulatory factors that compel the male’s role in the process. Finding a way to tweak that performance could expand crop cross-breeding possibilities.
PROVIDENCE, R.I. [Brown University] — Millions of times on a spring day there is a dramatic biomolecular tango where the flower, rather than adorning a dancer’s teeth, is the performer. In this dance, the female pistil leads, the male pollen tubes follow, and at the finish, the tubes explode and die. A new paper in Current Biology describes the genetically prescribed dance steps of the pollen tube and how their expression destines the tube for self-sacrifice, allowing flowering plants to reproduce. (more…)
The widespread disappearance of stromatolites, the earliest visible manifestation of life on Earth, may have been driven by single-celled organisms called foraminifera.
The findings, by scientists at Woods Hole Oceanographic Institution (WHOI); Massachusetts Institute of Technology; the University of Connecticut; Harvard Medical School; and Beth Israel Deaconess Medical Center, Boston, were published online the week of May 27 in the Proceedings of the National Academy of Sciences. (more…)
Complex organic compounds, including many important to life on Earth, were readily produced under conditions that likely prevailed in the primordial solar system. Scientists at the University of Chicago and NASA Ames Research Center came to this conclusion after linking computer simulations to laboratory experiments.
Fred Ciesla, assistant professor in geophysical sciences at UChicago, simulated the dynamics of the solar nebula, the cloud of gas and dust from which the sun and the planets formed. Although every dust particle within the nebula behaved differently, they all experienced the conditions needed for organics to form over a simulated million-year period. (more…)
In the wake of a mass extinction like the one that occurred 445 million years ago, a common assumption is that surviving species tend to proliferate quickly into new forms, having outlived many of their competitors.
But new research shows that tiny marine organisms called graptoloids did not begin to rapidly develop new physical traits until about 2 million years after competing species became extinct. (more…)
