But now hormones are being found to have impacts beyond the individual animal that produces them. They reach from one generation to effect the very survival of the next. They also communicate messages about the environmental conditions affecting the parent generation to the offspring which may help the new generation adapt to its environment. Zoologist Hubert Schwabl is studying this phenomenon in canaries and egrets. It is one of several maternal effects that enhance an offspring s survival and fitness.
Parents convey more than genetic information to their offspring.
For example, it is well known that well-fed mothers have bigger, healthier offspring. Maternal effects also include such things as nest site selection, variation in providing nutrients to offspring, the ratio of females to males among offspring, and now, the transmission of specific, powerful hormones that orchestrate behavioral development. These non-genetic contributions can have profound ecological, behavioral, and evolutionary implications. Animal breeders have been aware of non-genetic effects for decades, but viewed them as noise that obscured the genetic variation they were interested in. Schwabl s laboratory investigates the transmission of maternal hormones into bird eggs and the effects of the hormones on the progeny.