Ripley in a Dish

If you're a fan of the Alien movies with Sigourney Weaver, she plays the ultimate hero, Ripley. In the fourth movie of the series, there was a "company" effort to clone her and so you saw incubation chambers with floating version of Ripley in various stages of development.

The thing is, Dave, it's not so futuristic. Scientists have gotten pretty far with test tube embryos of mice. In one experiment, while some embryos were left in a mother's womb, others were harvested and grown in the lab. The lab ones grew in a nutrient solution first then were transferred to a gently swirling glass beaker.

Amazingly the embryos' development followed their genetic code whether they were in the uterus or lab. By day eleven, a beating heart appeared along with buds of tissue for limbs, signs of the digestive tract and auditory and visual systems. At this point, the embryos in the lab needed a functioning blood supply to get to full term but that's still a challenge scientists haven't met.

Being able to view closeup how mouse embryos develop can maybe give us a better insight into birth defects and how to intervene to improve human health. As for whether we can be grown in a lab? Our embryos are highly complex and while our information is also stored in genetic code, there's likely to be a lot of cross-talk with the mother's cells and tissues crucial to our growth. Plus, just as in the Alien movie, the many incomplete and defective versions of Ripley is a very real ethical issue.

Still, like it or not, one day it's coming.