Why does Scythers speed fall upon evolution?

Question

If i had a Scyther, and I trained it up to high levels before evolving it to a Scizor, wouldn't it have more Scyther-like Stats (extra speed for example) because it has leveled up that much with Scyther base stats, and has leveled up relitively few, if any levels with Scizor base stats? Doesn't it gain the stats on level up? or is that just an indication of how your stats have changed? Why would the stats change automatically when the base stats change? i would have thought the Stats would remain, and you would just get different amounts on Level up once you had evolved.

P.S. Does this also mean that if i had a mudkip, and kept it as a mudkip until it was nearly level 100, then allowed it to evolve into marshtomp, then swampert; by lvl100 would it have the same stats as a mudkip which evolved at lvl16 and again at lvl36? or would it have lower stats?

Answer 1

No. It's based on a rigid math equation, so the absolute highest speed he [Scizor] could have without the help of an item or stat raising move is 251.

It falls because Scizor has a different base speed than scyther. HIs IVs, EVs, and nature all remain constant if he evolves, and his level goes up (which would also go up with scyther, so it won't count for this) but that base speed, which is on the numerator, goes down. Since you have a smaller number on the numerator, this will result in a smaller number since it's being divided by the same thing.