Saturday, February 15, 2014
Recapitulates everything?
Tantalizing bit of clever observation in embryology. Researchers at Cambridge made a sort of fake uterus, and persuaded mouse embryos to implant in the fake uterus where they could be observed carefully. Before implantation, the embryo was a formless blastula, resulting from the first few stages of cell division. At the moment of implantation in the fake wall, the blastula reorganized itself into a radial pattern with wedge-shaped cells; then it began re-forming into a bilateral dual-tube thing that looked familiarly vertebratish.
Best pictures are in the 'Extended PDF' file. Available without paywall! Thanks, Cambridge Univ!
Plants are generally radial because they're rooted, but only a few typically sessile animals (coelenterates and echinoderms) are close to radial. Everything else is strongly bilateral.
You can imagine the designer saying: Hmm. Let's give them a chance to try amorphous, radial and bilateral, and let each creature continue with the form that suits it best.
Labels: Grand Blueprint
¶ 10:54 AM
