Unlike frogs that metamorphose from tadpoles into adults

[750plus]

I see.

Thanks Tim.

[tim]

You're welcome!

[750plus]

nah. the sentence is still fine without "they", for at least 3 different reasons:

1/
in context it's obvious that the researchers "concluded xxxx" and "recommended yyyy".
basically no one would even think of the alternate explanation, unless (s)he were completely ignoring context/meaning and looking purely at mechanics (= always a bad idea).

2/
also, the idea that a lifestyle can "recommend" something is absurd on its face. if someone were hypothetically to read the sentence that way, (s)he would IMMEDIATELY know that this is the wrong interpretation.

3/
it's more natural to associate "recommended" with the other past-tense verb ("concluded") than to associate it with the present-tense "lead".

I just missed replying here.

Mr. Purewal, you are amazing. Such clear and to the point explanations. The only reason that I visit Manhattan Forum is because I know I can get the best possible explanations from you.

A big thanks !

[RonPurewal]

you're welcome.