When the organism become bipedal, they walk with 2 legs so there are 2 arms that were unused. Some of them try to use that hand by grabbing stick or stone, leading to tools. They start to think more to develop tools and their brain capacity become increased.
The ability to use stone tools will help in food digestion since it can break the food easier. This reduces the needs for bigger teeth/jaw.
It was at that POINT MUTATION began
Answer:
Near water, change in elevation, or change in latitude.
Explanation:
The complementary pair would be 3' TACCCCGCG 5'
I hope I helped!
