/sci/ - Science & Math

>>15807263
Are you high? Animals slowly grow and lose limbs all the time. It takes tens of thousands of years for a structure as large and complex as an arm to develop and before it's used as an arm it will be used as a flipper. That flipper will represent an advantage, a disadvantage, or a neutral change and selected for or against accordingly. Look up vestigial organs.

>You think most evolution is change in previous "structures." It's clear you haven't even taken high school biology.
A assume you're talking about genes. When you get older and go to college you will learn about phenotype which is the expression of genes. Structures that are altered reflect a change in phenotype which implies but does not necessitate a change in genotype.