Page 28 - The Evolution Impasse 2

26 Left-Handed Amino Acids (Levo-Amino Acids)

L- Left hand ed ami no ac id D- Right-hand ed ami no ac id

The ques tion of how pro teins dis tin guish left-hand ed ami no ac ids, and how no right-
hand ed ami no ac ids ev er be come mixed up in them, are ones that ev o lu tion ists can -
not an swer. They can nev er ac count for such unique and ra tion al se lect iv i ty.

Amino ac ids from ei ther group Assume for a mo ment that life
can eas i ly bind to geth er with one an - did come in to ex is tence by chance,
oth er. However, re search has re - as ev o lu tion ists main tain. If so, there
vealed a most as ton ish ing fact: The should be equal amounts of right-
pro teins in all liv ing things, from the and left-hand ed ami no ac ids in na -
sim plest to the most com plex, are ture, both be ing the re sults of
made up sole ly of left-hand ed ami no chance. Therefore, there should be
ac ids. Even if just one right-hand ed var y ing lev els of right- and left-
ami no ac id is add ed to a pro tein's hand ed ami no ac ids in the bod ies of
struc ture, that pro tein will be come all liv ing things, be cause chem i cal ly
func tion less. ami no ac ids from ei ther group can
In some ex per i ments, bac te ria eas i ly com bine with one an oth er.
have been giv en right-hand ed ami no The fact re mains, how e ver, that
ac ids, but the bac te ria have im me di - the pro teins in liv ing or gan isms con -
ate ly bro ken down these ami no ac - sist sole ly of left-hand ed ami no ac -
ids—and in some cas es, have re con - ids.
struct ed from these frag ments left- How do pro teins se lect on ly left-
hand ed ami no ac ids that they can hand ed ami no ac ids? And why do
use. no right-hand ed ones ev er creep in?

The Evolution Impasse II