00:01
Hello, students.
00:01
So, in this question, they have asked, according to the evolutionary medicine textbook that you observe, what is the accepted hypothesis for loss of skin pigmentation that you observe in the northern europeans? now, if you observe with respect to northern europeans, you will observe that they are the ones that observe less or absorb rather less intense heat or less intense light, right? so, in this case, what basically happens? they are not having that much light in their area, right? so as a result of that, they have less pigmentation, correct? but one more thing that you will observe is that although the intensity is less, they are still exposed to the uv radiation or the uv light, right? so here one thing you will observe with respect to evolutionary medicine textbook is that it states that the adaptations have become in such a way with respect to northern europeans that you will observe that this loss of skin pigmentation is only adaptive such that there is ability to synthesize the vitamin d from uv light itself.
01:21
Right so if we observe the first option here they have given that with less intense light in the northern europe less pigment is necessary for the protection from uv light is this statement correct no no matter how less the intensity of the light is you will observe that protection with respect to uv light is very much necessary coming to the second one adaptive wherein you are to observe that ability to synthesize vitamin d from uv light is going to happen.
01:54
So this is the evolution that you're going to observe with respect to northern europeans wherein they can synthesize vitamin d from the uv light here.
02:04
So this is one of the right options.
02:07
Coming to the third one.
02:08
It is a result of greater sun exposure over the individual's lifetime.
02:13
If there was greater sun exposure, then the melanocytes would have been increased.
02:17
In number...