There is so much that we don’t know about the phenomenon of life. As someone who likes to imagine what might be out there in the stars, it’s easy for me to get wrapped up in dreams of alien life or other inspiring sci-fi ideas. More than a couple of my blogs in the past have included stories that sparked hope for finding alien life (read "Lake on Mars and Ancient Worms," "Exciting Advances in Biology, and Thoughts on Futurism," and "NASA's Latest Mars Discoveries and Technology's Role in the Lives of Children"). All this dreaming sometimes makes me overlook just how strange and alien life right here on our own planet can be. In the last couple of weeks, I have come across some stories in the world of science that have really piqued my interest about what we still don’t know about life right here on our own blue marble. Both of these discoveries challenge our understanding of life mysteries, whether those mysteries be hidden deep below our feet or right in our own bones.
One discovery that I caught word of this last week was announced by the Deep Carbon Observatory (DCO), an international group of over 1000 scientists who study the carbon cycle within the Earth’s crust. At the most recent annual meeting of the American Geophysical Union, the DCO revealed the results of a 10-year-long study combining world-wide efforts to sample and study the earth deep below our feet and the seafloor. What they found has been called the “Galapagos of the deep.” By sampling up to 2.5km (1.5-miles) below the seafloor and up to 5km (3.1-miles) deep in continental mines, the DCO revealed what they are coining the “deep biosphere.” This rich, unvisited environment is huge and is estimated to contain up to 70% of all the bacteria and archaea on the planet. It has a volume of approximately 2.3 billion cubic km, or almost twice the size of all the world’s oceans, and it contains 2 to 6x1029 cells, or 245 to 385 times more carbon mass than all human life combined.
I was completely stunned to learn that such a large environment went undiscovered by us for such a long time. These lifeforms are much different than their counterparts on the Earth’s surface because they live in an environment that has extremely high pressure and temperature as well as extremely low access to energy and nutrients. Scientists on the team believe that these bacteria live their lives subsisting off very few nutrients – sometimes only surviving off what they can leech from rocks. This study expands our understanding of what conditions life can survive under here on earth. We have yet to define these limits, but getting closer to defining them broadens our range of what to look for when hunting for life on celestial bodies besides earth.
They also are thought to live on “near-geologic” timescales. The finding of ancient bacteria here pushes our boundaries of how long we believe life can live. This is not the only recent story involving the study of investigations into the limits of lifespan. If you remember our blog from last year about reanimated frozen worms from Siberia, other studies are changing our conception of lifespan limits alongside this one. There is even a planned 500-year long study that has vacuum-sealed cells of Chroococcidiopsis and Bacillus subtilis into vials to test the limits of their abilities to reanimate after long periods in a dried and nutrient-starved state. Studies like these never cease to amaze me because they serve as reminders that there is way more to life than just the human perspective.
The discovery of the deep biosphere is a huge, untapped well of questions. We’re not sure yet how life got into the deep earth, whether it started there and moved up towards the surface or if it happened the other way around. We don’t know how this ecosystem moves around or effects the carbon on the surface. We also are not yet sure of which source of energy is most important to the ecosystem. All these mysteries are what make this discovery so exciting. We have found an entirely new ecosystem for science to investigate, and discoveries made from investigating it will likely continue to revolutionize our understanding of life, on earth and in general, going forward.
New Blood Vessels Discovered:
The other discovery that caught my eye for the blog this week was that of finding a new network of previously unknown-of blood vessels in the walls of our bones. These new blood vessels, coined “trans-cortical vessels” (TCVs), were found when scientists used chemicals to turn a mouse bone transparent. When they looked at a piece of human thigh-bone using the same method, they found the vessels there as well. Previously, scientist only knew of vessels entering bones from their ends or halfway down their shafts. They now believe that these vessels are the primary routes for most blood entering and leaving long bones. These TCVs also likely play large roles in bone diseases, such as osteoporosis, as well as in the transport of immune cells that are created in bone marrow.
Check out this article from New Scientist that includes a 3-D rendering of a bone with these vessels included.
After reading about this study, I couldn’t stop thinking about how crazy it is that we are STILL finding new parts of the human anatomy. We have had advanced microscopes, x-rays, and other imaging techniques for so long that I am surprised that we’ve missed entire parts of the circulatory system until now. And this isn’t the only discovery shaking up human anatomy this year: back in march, scientists published a paper outlining the discovery of a possible new organ that consists of a network of fluid-filled channels between various tissues all throughout the body. Who knows, maybe there are even more pieces of our anatomy left to discover.
It is yet to be seen how the discovery of these new anatomical structures will effect the understanding of our bodies going forward, but every step towards a better understanding helps when developing new medical procedures. Hopefully, as we learn more about our bodies, we will be able to advance medicine further and help more sick people than we were ever able to before.
I think there is nothing more exiting in science than finding something entirely new. When science gives us a new piece of information, it opens up doorways to other critical discoveries. It’s not often that scientists find completely new anatomical structures or brand-new ecosystems beneath our feet that are larger than all our oceans. Every time I hear about discoveries like these, I always imagine one step ahead. Could these discoveries be the keys to finding out even more important information about our universe? Only time will tell, but, for now, we know that life as a whole is still a phenomenon that probably has many surprises still in store for our scientists to discover.
One more quick thing before I go: The day after publishing our last blog post, one of its subjects of discussion, He Jiankui, the Chinese scientist who shocked the world last November when he told the world of his efforts to produce genetically-edited human babies, was fired from his position at the Southern University of Science and Technology in Shenzhen, China. News also broke of several prominent geneticists knowing of He and his secret work before its release in November, including an American Nobel laureate, Craig Mello, and CRISPR pioneer Jennifer Doudna, among a few others. Though neither scientist has any direct ties to He's research, foreknowledge of the experiment has caused even more concern among scientists. As I promised in the last blog, this story continues to develop as the worlds of science and ethics scramble to figure out how to cope with He’s unsolicited and risky work.