The given passage emphasizes on the altruism and gives examples of humans and animals exhibiting the altruistic behaviour. According to passage, Individuals performing altruistic acts do not gain anything for themselves. However the lecturer contradicts this point by giving findings of a study and some examples which casts a doubt in the conclusion made in the passage.
Firstly, according to passage in meerkats group one individual will act as a sentinel and will look out for predator while putting itself in danger as it standing alone. But the lecturer argues that the sentinel meerkat will stand next to it's burrow while standing guard so it will be easy for it to escape. And also the lecturer points out that the alarm cry made by the standing meerkat will scare the predator of from it and will prompt predator towards the group which will be either scattered or sticked together upon hearing the alarm which makes it easier for the predator to hunt.
secondly the claim made in the passage about the standing guard meerkat will starve while the other members of the group are feeding themselves is put down by the lecturer by pointing out that the sentinel meerkat will feed itself stomach full before taking the on-guard duty.
The passage claim about the humans who donate organs to either strangers or family members will gain nothing in return, but the lecturer not completely agree with it he points out that the person who donates the organs to either to strangers or family members will get appreciation in return and will make his self worth increase. And the lecturer points out that many people will do anything to increase their self worth.
In this way, the lecturer casts a doubt in the conclusion made in the reading passage.