From that article:
Hayashi and his team cultivated the DNA in the skin to create stem cells, and then stimulated the stem cells to become egg cells. The eggs were then fertilized with mouse sperm in the Petri dish. Fertilized eggs were implanted in mice to mature. About one out of 100 of these completely artificial eggs produced a healthy baby mouse.
Still sexual reproduction. The work on actual ‘cloning’ using the genetic material of just an individual in an unfertilized ovum continues but the process of coaxing an egg to develop into a zygote is more complicated and poorly understood than the popular science press would have you believe.
I wasn’t making a direct comparison between the likelihood of life on any of the water- or hydrocarbon-bearing Galilean and Saturnian moons but rather between those and extant life on the surface of Mars. While a lot of people seem to expect that we’ll find life on Mars, nobody has been able to provide a mechanism by which it would exist and there is no evidence of any active biosphere on Mars, either on the surface or shallow subsurface despite over four decades of intense (albeit sporadic) exploration. If life ever existed on Mars it was probably within the first billion years of its existence and has left only chemifossil traces.
Life could exist on Europa, Ganymede, Titan, or Enceladus, however, and we just haven’t been able to sample the environment sufficiently to even look for waste products or other evidence of life. Most intriguing are suggestions that even Io could harbor some kind of sulfur-based life, although what that biochemistry would look like is anyone’s guess. Titan, however, could have life existing on its surface where it could be readily observed versus having to somehow drill or probe deep into subsurface oceans, so as a target of opportunity it holds more immediate promise, and it also offers insights into the complex environments we might find on extrasolar planets with atmospheres.
Stranger