What is the difference between effective and efficient selection?
You have a word problem here, not really biology.
Efficacy means &quot;power to produce the desired result/effect&quot;
Effective means &quot;producing the desired result&quot;, stressing the ability to produce that result
Efficiency means &quot;degree of being efficient&quot;
Efficient in turn means &quot;ability to produce desired result with little waste&quot;
Efficacy and efficiency are not interchangeable as they have different meanings, albeit a subtle difference. You could on the other hand us efficacy and effective as synonyms, though properly the synonym of efficacy is effectivness.