In the lecture the professor told that the meerkat group was observed very closely than before. Then some interesting facts came out which oppose the arguments made in the passage.
Firstly, the meerkat who stand as guard eats before its work. So, being in full stomach it has no need of food any more. Therefore, not taking food as stated in the passage is not altruism.
Secondly, when the guard meerkat cries an alarm upon approaching a predator then the sentinel has the greater possibility to escape as it sees the predator first. Moreover, when the meerkat group hears the alarm then they will gather together or scatter. So, they will catch the attention of predator putting themselves in danger. Therefore, actually the group of meerkat are in danger when predator comes. This also opposes the altruistic behavior of the sentinel.
Finally, the group of meerkat not the sentinel go in search of food which also is dangerous for them. Now, it can be told that the sentinel is nowhere altruistic.
There are example of human being also in the lecture. In the passage it has been mentioned that, when a person donates his/her body part selflessly then it can be an instance of altruism. But the professor opposed this point saying that the donor achieves much appreciation and recognition from the acceptor as well as from society. So, the donor is actually getting something which may be non-material, and that's why this cannot be regarded as pure altruism.