Final answer:
The statement about antifreeze proteins arising in fish less than 20 million years ago is false, as genetic evidence suggests that adaptations like these could have been present in fish earlier than that timeframe.
Step-by-step explanation:
The statement that antifreeze proteins arose in fish less than 20 million years ago, coinciding with sea level glaciations is false. Antifreeze proteins have been found in fish that are older than 20 million years. For instance, the homologous genes coding for the carbohydrates that are presented on the surfaces of red blood cells are found in amphibians and mammals but not in fish, dating back to at least 20 million years ago, which implies the ABO gene system's last common ancestor is at least that old. This suggests that antifreeze proteins could have been required by fish prior to that timeframe, as adaptations to cold environments.