A plant hybridizer has been making multiple crosses between varieties of blackberry and raspberry, trying to produce a plant that produces the best fruit on the best and hardiest canes. One particular cross appears to be perfect, with one exception; the fruit is sterile, and produces only sterile seeds.

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .

i believe the answer is snake.