Final answer:
The population of birds contains more lizards with no frills, which is the dominant trait.
Step-by-step explanation:
Population Genetics and Natural Selection
In this scenario, the presence or absence of frills in lizards is determined by a dominant and recessive trait. Not having a frill is the dominant trait, as indicated by the 34 lizards with no frills compared to the 16 lizards with red frills. This means that more lizards in the population express the dominant trait.