| This is faulty reasoning. To think that the female reproductive system developed prior to the fetus (in order to pave way for nurturing of the embryo) is implying evolution is a purpose-driven, goal-oriented process - a line of reasoning not too far from "intelligent design". Not to mention the egg-chicken dichotomy is absurd. There was neither a "first chicken" nor a "first egg". Single celled protists first developed sexual reproduction about 2 billion years ago as a means of producing genetically variable offsprings. It may be assumed both the offspring and the reproductive machinery of the parents developed concomitantly as life was making a shift from uni-cellularity toward multi-cellularity. As for mammals (which includes us humans), the placenta, which serves as an important barrier between the mother and the fetus (only letting nutrition pass through), is of viral origin. Placental syncytiotrophoblasts SCT-1, SCT-2 proteins are derived from endogenous retroviruses. Our genome is full of fossils of viral DNA - accumulated over several millions of years. If these viruses had not apt-get install-ed biological chroot jails, we would not have been born at all.. (obviously some other modes of reproduction may have been developed) Carl Zimmer has some interesting write-ups on this topic: http://blogs.discovermagazine.com/loom/2012/02/14/mammals-ma... http://www.nytimes.com/2010/01/12/science/12paleo.html For those interested in evolution of sexual reproduction and "viro-biome", I recommend Carl Zimmer's Planet of Viruses and Matt Ridley's Red Queen. I agree the article is a bit sensationalist. Look at it in this way: had it been a boring, academic, science-journaly piece, many of us wouldn't have waded through the article at all... Obviously the target audience for that article (and the site) are general science-buffs and not only embryologists or molecular biologists. Personally I think some dramatisation (to make the content more appealing to general audience) is acceptable - so long as the subject matter doesn't deviate too much from reality. PS: apologies for my broken english :) PPS: Re: the chicken & egg question - the egg came first because reptilians laid eggs. Chickens, and birds in general, are descendants of dinosaurs. |