Tuesday, March 29, 2016

Tiny slices of life

My science-centric posts tend toward astronomy and physics, but those aren't my only interests. Today we'll look at some exciting news from biology. Call it a walk on the wild side.

In round numbers, Earth is about 4.5 billion years old. Life has existed on Earth for at least 3.5 billion years. But complex multi-cellular life -- complex as in sponges and jellyfish, not people -- goes back a mere 0.6 billion years or so. Why did complex life finally appear? Perhaps the answer is in this "Startling new finding: 600 million years ago, a biological mishap changed everything." A key quote:

Incredibly, in the world of evolutionary biology, all it took was one tiny tweak, one gene, and complex life as we know it was born.

Most likely that (and many another critical) mutation arose as the result of some stray bit of cosmic radiation. Evolution exploits radiation, but that hardly makes radiation an unmitigated good. In particular, the complex multi-cellular lifeforms known as human beings are very susceptible to damage from radiation. We can usually stay away from serious dosages -- and we all hope things remain that way! -- but incidents like Chernobyl and Fukushima do happen. For when they do, it's good to know of a new cellular therapy to tackle the problem. See "Israeli placental cell therapy could cure radiation sickness." As in:

The Haifa-based company said they have developed a placenta-based cell therapy injection that can fully cure patients with multiple organ failure caused by high radiation exposure.

One type of human cell that tends to get around is ... sperm. But what if they're insufficiently mobile to get around? Hi-tech to the rescue! As in "Steerable, Motorized Cyborg Spermbots Take on Infertility." (Hmm. Now I've got the Beach Boy's tune "Get Around" in my brain. How about you?)

When sperm do get around, that often leads to babies. Outside of SF, no one is -- yet -- producing designer babies, with the many ethical and practical issues that would raise, but biologists are beginning to do genetic research with human embryos. See "Britain gives scientist go-ahead to genetically modify human embryos." While AFAIK legal in the US, such research would not meet current NIH guidelines ("Statement on NIH funding of research using gene-editing technologies in human embryos").

Biologists have sequenced  many genomes, but how well do they understand what genes do? Not as much as we might hope. From a particularly fascinating long-term study, see, "The Mysterious Thing About a Marvelous New Synthetic Cell: Scientists have created a bacterium with a minimal, life-sustaining genome, but they don’t know what a third of its genes do." The project set out to build a synthetic cell(*) from the bottom up, gene by gene, to determine which few genes are absolutely essential to life. That, it turns out is a hard problem! And (as that headline reveals), biologists don't understand a third of those essential genes. A humbling thought ...

(*) It's named Synthia ... how cute is that?

Now I'm leaving my cell (er, lovely writing office) for a break.

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