Welcome to brain Stuff production of I Heart Radio. Hey, brain Stuff, Lauren Volga bomb here. Three billion years ago, things on Earth were different. For one thing, there wasn't all this oxygen all over the place. The first cyanobacteria had to figure out a way to live on volcanic carbon dioxide, water, and sunlight alone. These old timey organisms lived anaerobically, that is, without oxygen. Strangely enough, what we're breathing today is the type of atmosphere that they made
possible for us. Because the byproduct that they excreted oxygen, eventually overtook Earth's atmosphere. Any remaining anaerobic organisms were forced into the oxygen less nooks and crannies of the planet and kept simple and single celled. However, when there's a rule, there's usually an exception, and a group of scientists have discovered a small parasitic niderian that is a tip of
a jellyfish that apparently doesn't use oxygen to breathe. They publish their findings in the February issue of the Proceedings of the National Academy of Sciences. This animal, taxonomical name Hanagaya salmon acola, is a tiny parasite with a long tail that feeds on the muscle tissue of salmon and other fish. It's a eukaryote, which just means that it's a member of a broad group of organisms that includes most of the living things that you can see with
your naked eye animals, plants, fungi, et cetera. The cells of eukaryotes contain all sorts of fancy organelles that they are more primitive counterparts the prokaryotes don't have. One of those organelles is the mitochondrian, a structure that has a tiny genome all of its own, separate from the rest of the organism, and which eukaryotic cells use to produce energy with the help of oxygen. But within the larger groups that we call eukaryotes, there are a few single
celled non animal species that are anaerobic. They don't have mitochondria, but rather something that scientists call mitochondrian related organelles. Annagaya salmnicola is the first animal to have this feature. It's all very strange, so how did they get this way? For the article this episode is based on how Stuff Works. Spoke with study co author Stephen Atkinson a research professor in the Department of Microbiology at Oregon State University. He said,
the ancestors of Hanna Guia almost certainly had mitochondria. All its closest relatives have mitochondria, so the evolution to an anaerobic lifestyle and the loss of functional mitochondria appears to be a recent adaptation of that species alone, at least that we know of so far. In the cells of typical animals, the mitochondria use oxygen in a multi step process to create chemical energy. The research team found that this parasite has just had to adapt to an environment
with very little available oxygen. Without the need for mitochondria, it lost the genetic instructions for at least several parts of the processes that use oxygen. So by losing that mitochondrial genome, the parasite saves energy by not having to copy genes for things that no longer needs. But how can it survive without oxygen in the first place, Atkinson said, we presume that it must instead absorb molecules related to energy production from the host cells, which have already done
part of the processing. Stealing something from the host is fundamental to parasitism. Like many important discoveries. This finding was totally unexpected. The researchers were hoping to compare the genomes of two small parasites, but each time they tried to run that of the Hanagaya salmonicola, something was obviously very weird. Looking into it further, they found itsels contained a little empty bag where a mitochondria and might once have been.
Atkinson said, this discovery has expanded our understanding of what it means to be an animal by showing that even complex life can evolve in a way to succeed in environments without oxygen. Knowing that anaerobic animals can exist alerts us to the fact that we must be on the lookout for this and other species and maybe look in anaerobic environments for animals where we never would have looked before.
Specifically from mixing zoan parasite research. It means we will look for unusual or missing mitochondria in other species from now on to try and discover the connections between hosts, tissue and environment that lead to loss of mitochondrial function to take advantage of anaerobic metabolism. The discovery of anaerobic mechanisms in these parasites could also open a new avenue for treatment, as specific drugs have been used to target
other anaerobic parasites. Today's episode is based on the article can you live without oxygen? This animal can on how stuffworks dot Com. Written by Jesslan Shields. Brain Stuff is a production of Our Heart Radio in partnership with how stuff works dot Com, and it's produced by Tyler Clain. Four more podcasts my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.