BOSTON, June 3 (UPI) — Until now, synthetic biological systems have focused exclusively on either analog or digital computation. Researchers at MIT have devised a technique for creating cellular gene circuits capable of complex computation.

Analog computation, also called continuous computation, is the type of processing happening as the human eye adjusts to changing light conditions. Digital computation involves binary decision making, on or off processes.

The new synthetic cellular circuitry designed by MIT scientists performs like a comparator, receiving analog input signals and converting them into digital output signals.

[Image: An animal that looks like a plant. From simple.wikipedia.org/wiki/Stick_insect#/media/File:LeafInsect.jpg.]

Future genetic engineering may create animals that can photosynthesize like plants. These animals would require less food because they will make some of it from sunlight. In principle, even humans could be modified this way!

There are already some natural cases of animal-plant integration. Some marine flatworms have algae living in their translucent bodies,between their cells. Increasing the degree of plant-animal integration further, the method used by coral and various other marine animals is to have symbiotic algae living, not between their cells (like the flatworms), but actually inside some of their cells. The algae are typically of the genus Symbiodinium, and live in “symbiosomes,” blobs inside the animal cells that hold the algae separate from the rest of the cell. Each symbiosome is a kind of really, really tiny terrarium (a “nanoterrarium”) maintained by the finely engineered nanotechnology device of nature we call the cell. The cells supply the algae, in its symbiosome home, with basic chemicals and exposure to light. In return the algae produce nutrients that the animals extract from the symbiosome and use. In coral, when these algae die the coral loses color and, if not reversed, itself dies in the phenomenon called “coral bleaching.”

Taking the algae-animal combination another step, there are species of sea sponges, a primitive type of animal, that host algae in leaf-like structures that they grow to better capture underwater sunlight. That’s right: animals with leaves.

The degree of integration can be tighter still. Observe that algae (like their descendants, the plants) do photosynthesis using chloroplasts. These are small green organelles, organelles being the tiny nanomachines that serve as “organs” of cells. Chloroplasts thus give plants their green color. The chloroplasts are thought to have once been independent organisms that, eons ago, took up residence inside cells of other organisms, where they have lived ever since. What about animals whose cells can contain chloroplasts directly, eliminating the inefficiency of using algae as the middleman? There is no reason why this could be created by genetic engineering. Nor is there any reason why something like this could not exist on some other planet already.

[This passage is slightly modified from my book The Human Race to the Future, published by the Lifeboat Foundation.]

The oldest space dust yet found on Earth suggests that the ancient atmosphere of Earth had significantly more oxygen than previously thought, a new study finds.

Although oxygen gas currently makes up about one-fifth of Earth’s air, there was at least 100,000 times less oxygen in the primordial atmosphere, researchers say. Oxygen easily reacts with other molecules, which means it readily gets bound to other elements and pulled from the atmosphere.

Previous research suggests that significant levels of oxygen gas started permanently building up in the atmosphere with the Great Oxidation Event, which occurred about 2.4 billion years ago. This event was most likely caused by cyanobacteria — microbes that, like plants, photosynthesize and release oxygen. [Infographic: Earth’s Atmosphere Top to Bottom].

According to established scientific knowledge, complex cells (called eukaryotic cells) can’t survive without mitochondria — tiny organelles that control respiration and power movement and growth. You can think of them as tiny batteries converting energy so that cells can go about their business, but they perform other key jobs, too. They are, as the common adage goes, the powerhouse of the cell.

Now, scientists working in Canada and the Czech Republic have made a surprising discovery: a eukaryotic cell without these mitochondrial batteries. It’s an unprecedented find that’s likely to change our thinking about how some types of cells can exist and grow. In other words, life is more flexible than we thought.

“[Mitochondria] were considered to be absolutely indispensable components of the eukaryotic cell and the hallmark of the eukaryotic cell,” team leader, Anna Karnkowska from the University of British Columbia told Nell Greenfieldboyce at NPR.