The vast land of China holds many secrets and among them may be the fact that we're mistaken in our belief that dinosaurs are extinct. Some scientists believe that fossils found there reveal that a winged dinosaur evolved into the modern bird. Maverick scientist John Ostrom was particularly excited when the all-important missing link in his theory was found in China about three years ago. He explains its significance in Life Before Birds: Dinosaurs In Your Garden (Pearl, 10.45pm). The fossil in question is of an animal lying half way between small predatory dinosaurs and the oldest known ancestor of the bird, archeopteryx, the latter having both feathers and reptilian teeth and jaws. We won't be surprised to see these creatures brought back to life on our screens with the help of sophisticated computer animation. What is more extraordinary is the suggestion that dinosaurs could be recreated for real, by switching off the genes in a bird that make it bird-like. Jurassic Park may not remain a Spielberg fantasy for long. This film on the origins of birds is a build-up to Sir David Attenborough's Life Of Birds coming later this month, as the trailers keep reminding us. ATV, though, has stolen some of TVB's thunder by rerunning Attenborough's brilliant series on animal behaviour, The Trials Of Life (World, 9pm). This series, made in the 1980s, may not be new to Hong Kong, but it has not been seen for some time and it is a new acquisition for ATV. Whether or not you've seen The Trials Of Life before, it is the most extraordinary television, reaffirming Attenborough's status as the world's leading creator of natural history programming. It took more than three years to make and Attenborough travelled almost half a million kilometres in the process. In this episode, Arriving, images of the many amazing ways animals have evolved to create new life provoke wonder whether seen for the first or third time. Attenborough focuses on the most spectacular solutions to creation, such as the one billion lives launched once a year by land crabs into the water off Christmas Island, and the massive annual spasm of the giant clam. Superb photography reveals the incredible beauty of Owl Butterfly eggs which are only the size of a grain of sand. The only problem is we do see and hear an awful lot of Attenborough in Hong Kong and by the end of the month he'll be on both channels on the same night. By then, many viewers may have had enough. A popular RTHK family drama first screened in 1977 has been revived 22 years later. In When We Were Young (Home, 7pm) Ka-kei and Siu-man, two children who featured in the 1970s show, have grown up and are bringing up their own children. The pair are played by the same actors, Jimmy Wong and Queenie Lo. Being an RTHK series When We Were Young has a worthy aim. Unlike many a more commercial television drama, it focuses on good parenting and encourages adults to communicate more affectionately and effectively with their children.