We're always learning new things about life on Earth, from discovering new species to learning how our cells keep us alive. But what about making life?

Last week, researchers said they had created a tiny synthetic bacterium that could help us understand the fundamental requirements for life. That's because this bacterium had the fewest genes of any known free-living thing. Researcher wanted to create an organism with a minimal genome, to help us figure out which genes are really essential for survival, and eventually to design more complex synthetic organisms.

So the team, led by scientists from the J. Craig Venter Institute, started with something nicknamed Synthia, a bacterium that the same team had created back in 2010, and was considered by some to be the world's first synthetic organism. Back then, they essentially made a copy of a bacterium's genome from scratch and inserted into the empty cell of a related bacterium. And the result, Synthia, fit the basic definition of life. It could make energy to live, grow, and self-replicate. 

But this time around, the team wanted to see how much of that genome Synthia really needed. So they began deleting genes that they thought might be dispensable, based on earlier research. They kept testing different combinations of genes in a trial-and-error sort of way, until they arrived at a living thing that was living, but seemed to have the fewest genes possible. They called the new organism Mycoplasma mycoides JCV-syn3.0. And it has a mere 473 genes. 

By comparison, the smallest free-living bacterium, called Mycoplasma genitaluim, has 525 genes, while humans have 20-to-25,000. And the crazy thing is, even after spending years building this thing, scientists still don't know what 149 of this new organisms genes actually do. That's like 30% of them. All they know is that they are vital for it to stay alive.

So we have this new living thing with a tiny genome, but there's still a lot to learn about the genetic foundations of life. But bacteria aren't the only synthetic things scientists are working on.

In recent years, there's also been at least some research done on electronic cigarettes. Last week, researchers from the University of Partas in Greece published a study, in a journal called Addiction, that compared different types of e-cigs to measure how much nicotine they deliver, and how consistent their nicotine delivery is over time.

They did this because, well, not a lot of research has gone into e-cigarettes. They're so popular, however, that agencies are having to catch up to figure out how to regulate and standardize them. So the scientists set out to compare some originals e-cigs that went on the market a few years ago, to newer ones that are being used now. They also wanted to see how both of those compared to pharmaceutical nicotine inhalers that are sometimes used to help people quit smoking. 

Now, all e-cigarettes have the same basic parts. There's a battery, a container for the so-called e-liquid, which is the nicotine mixture that turns into vapor, and then an atomizer, basically it uses a battery to power a heating element to vaporize the liquid into a gas. But different models of e-cigarettes have at least three different types of atomizers to provide the nicotine fix. 

The older models have a metal mesh or wick attached to the atomizer, which can vaporize the liquid that the user applies to it, one drop at a time. Then there are cartomizers, which are atomizers attached to a cartridge full of the liquid. They're pretty standard in commercial e-cigs these days. And, lastly, there are so-called clearomizers, which have a clear tank full of the e-liquid connected to a replaceable wick-and-coil combo that creates the vapor. This is a slightly newer technology. 

So the team created their own custom e-liquid to load up several brands of e-cigarettes, 3 with cartomizers, and 4 with clearomizers, and then used a pharmaceutical nicotine inhaler and a pack of cigarettes as controls. Then, they programmed a sort of "smoking machine" to puff on the different cigarettes, and after they collected the vapor and studied it, they found that clearomizers, the newer models, delivered nicotine more consistently than the cartomizers, and about the same as the pharmaceutical kind. Many clearomizer also delivered more nicotine with each puff than any other e-cigarette or even tobacco cigarettes.

So in addition to clearing the air, if you will, about what kinds of e-cigs deliver how much of the drug, the researchers say that their study could be used to test e-cigs in the future, so people know what they're getting. 

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