Easiest way to gain XP/levels is by analyzing DNA of animals and plants, you should get this along the way while going for the 'Edit the DNA of 1000 plants/animals' achievements, but if not:
1-Get a bunch of plants/animal families and speed up time to allow them to mutate
2-open edyGene with
3-select a plant/animal
4-click the DNA button to start analyzing (it gets faster as you level up)
5-once complete, repeat steps 3 and 4, you should gain a level for every 3-4 animals/plants analyzed, and the XP requirement per level seems the same, it doesn't get harder, should only take 20 min or less from level 1.