(2) (Of, or pertaining to) An organism that expresses the dominant gene (or allele). (ecology) (Of, or pertaining to) An organism or group of organisms having the most considerable influence or control in its ecological community among other organism.
Relevance. Rating Newest Oldest. Best Answer: Geological Period that lasted the longest: The Precambrian Era The Precambrian Era is the longest geological era beginning 4.5 billion years ago and lasting approximately 4 billion years. The Precambrian era is generally separated into two eons the first of which being the Archaean Eon.
View full size image. The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene (K-Pg) extinction event dated at 65.5 million years ago.In the early Cretaceous, the continents were in very different positions than they are today.t lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene (K-Pg) extinction event dated at 65.5 million years ago. In the early Cretaceous, the continents were in very different positions than they are today.