Complex sentence: Survival of the fittest and elimination of the weak is the law of nature but the immense potential or simply the power of science makes the weak and the meek stronger and also gives them a chance to compete with the fittest and the strongest on equal footing.
Split into simpler sentences: Survival of the fittest and elimination of the weak is the law of nature. But science makes the weak and the meek stronger and also gives them a chance to compete with the fittest and the strongest on equal footing.