Ever wonder how we're going to create humans who can breathe underwater? Of course you do. Now a study published this week about how algae insinuate themselves into salamander embryos (and DNA) could provide the beginnings of an answer.
We know that viruses can invade an organism, and eventually wind up integrating into that organism's DNA permanently. Human DNA is packed with all the virus DNA we've absorbed over the past few hundred thousand years. But could other microbes do the same thing? A group of biologists decided to find out, by studying the relationship between algae and salamanders. They knew that algae often snuck inside salamander embryos, but the question that nagged was what happened next. Now it seems likely that some salamanders are literally part algae. And this odd situation could be the foundation for biological tweaks that might help future posthumans live underwater.
Basically, it appears that algae sneak into developing salamander eggs, and become part of the salamander fetus as it grows. And the algae doesn't leave, either - some adult salamanders have algae DNA, which they are likely passing on to the next generation. That's right: Salamanders are part-plant.
According to a release from PNAS:
The researchers report that algae, which may come into contact with developing salamanders when the eggs are laid in pools of water, enter the embryos before the development of the salamander's adaptive immune system. Previous studies have proposed that the adaptive immune system prevents intracellular symbiosis between algae and vertebrate animals. Fewer algal cells were detected in later stage salamander larvae; however, tests revealed algal DNA in the reproductive tracts of some adults, which suggested to the researchers that algae may also directly transfer to salamander offspring from one generation to the next.
Here's where things get interesting for those of us who look forward to the Homo sapiens aquatic bio-expansion pack. The likely reason why this half-plant, half-animal symbiotic relationship evolved was because the algae snacked on nitrogen in the embryo's waste, while the embryo benefited from the oxygen in the algae's waste. OK, yes, they were both eating each other's poop, if you want to think of it that way. But more importantly, what it means is that algae could be built-in source of oxygen for organisms it decides to pair with symbiotically.
According to the authors of this study, we are now certain that algae can live within vertebrate tissues, which means - hey, why not in humans? We're vertebrates. Next time you're coming up with your mad scientist plan to design aquatic humans, consider algae implants. Sure you'd need to do a lot of bioengineering first, but algae could prove to be the foundation of a redesigned human who needs help pulling oxygen from the water.