1)They concluded that, alongside diet and climate, non-verbal social communication played an important but overlooked role.
-This one I think is a complex sentence because it has two subjects (They and non-verbal social communication) with their predicates and a subordinating conjunction which is "that"
2)We know that other factors such as diet, respiratory physiology and climate have contributed to the shape of the modern human face, but to interpret its evolution solely in terms of these factors would be an oversimplification.
-This one is similar to the first sentence.
3) Facial shrinking had become especially pronounced since the agricultural revolution, and the switch from being hunter-gatherers to farmers and then to living in cities.
-Two conjunctions, (Since, and).
Thank you!
