1

If so, the green algae would have been subjected to environmental pressures that resulted in adaptations that enhanced their potential to give rise to land-dwelling organisms.(From TPO 25 )

would haven

2

it is just a more formal sounding way of saying "had been", had this thing have happened.

If so, the green algae had been subjected to environmental pressures that resulted in adaptations that enhanced their potential to give rise to land-dwelling organisms.(From TPO 25 )

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.