The lecture is about Altruism wich the articule define as the behaviour of animals or people to help another or even put in danger themself to help another person or group. The articule state that the person or animal that do this don't get anything in returne, and the profesor doesn't think that. The articule gives two examples in wich this non careless acts take place and the professor refute them by explaining why they are actions with self interest. To begin with, the articule explain that the sentinel's meerkat, put him in danger in orden to let the group search for food while his is guarding for a predator, not be able to hunt his own food. But the professor contradict this saying that the whole squad eat before this and also says, that