Why do scientists construct recombinant dna molecules?

Aperson travels 35 km in 0.4hrs, followed by 53 km in 0.6 hr. what is the average speed

How was the climate when the ambulocetus was alive

Need an answer asap 45 points and brainlest to the first person to answer why do scientific theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record. must be in sentence form how can scientific theories on evolution and the fossil record change over time? must be in sentence form