Cryptic crossword No 1,505

Across

1. Synchronized knowledge? (11)
2. Pan-fried dog?  (3)
3. Branch of philosophy said to change every alternative system initially before it (7)
4. Charlatan roughly removed by queen's order... (7)
5. ...Poitín maker is nevertheless motionless (5)
6. Sic eh? Characters once or twice make waves on 21a (7)
7. Ancient Peruvian bean location? (5)
8. Limit steamy pot boiling (9)
9. Perhaps naturalists Irwin and Backshall interfered with same snake? (9)
10. Fresh bodies? Ask the French party! (5)
11. Insect width not applicable to feeler (7)
12. Verity is the head girl (5)
13. Recite recital to find sanctuary (7)
14. See 15d
15. Drowned valley turned around by lilting melody (3)
16. Choose tensile screws to build blockades (6,5)

Down

1.  Notions back in Mensa edition (5)
2. Italian baddies made artificial intelligence mess with basements of MAFF, DSS and DLHUC (5)
3. Lazily lingered with last of trainspotters for Marsh Flyers (9)
4. Note: hot amines cause loss of faculty (7)
5. Verbal evidence of involvement in singing group with Yakuza leader prompts investigation (7)
6. North Island ham worried girl (5)
7. Have a go at job that isn't evidence-led (9)
8. Wipe down, using several towels for starters (4)
9. Pays loss leader out of notices (4)
10. Charged particles emerge from imitation scope (4)
11. Involvement of hard female in crime dominance confused president. (9,2,5)
12. Sectarian vandalised local tipi (9)
13. Moves playfully? I neck it (7)
14. Interface within, phase aside (7)
15. Buffoon's instrument sliced by flying cyclist (5)
16. Making love is workers' power (5)
17. Raises masses (5)
18. Picked up better ventilated manor? (4)