Ecology, Evolution and Genetics. Solutions to many of the world's most pressing environmental issues require a basic understanding of nature at the organismal, population and ecosystems level.
Average. On average, women start to show around the fourth month of pregnancy, between weeks 14 and 17. By week 17 the uterus usually has expanded to just an inch and a half below the navel, making the pregnancy more obvious.
Confidence votes 25.5K. Smiling begins at birth; yet it is more out of natural instinct than to show an outward sign of pleasure. It has been found that this generally occurs at around 2 months of age. Babies smile in the womb, probably just to flex the facial muscles. Smiling to indicate pleasure starts generally around 6-8 weeks. Smiling begins at birth; yet it is more out of natural instinct than to show an outward sign of pleasure. It has been found that this generally occurs at around 2 months of age.  Smiling to indicate pleasure starts generally around 6-8 weeks.