Peter,
You may be interested to know that BBC's The Blue Planet is now touring the country as a live show.
It might be interesting for your dissertation to show how the shows are so popular that they are now even entering other areas of life...the show is playing at Wembley Arena, Nottingham Arena, Manchester GMEX and the concert halls in Cardiff and Birmingham.
More here
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As a lover of all natural history shows, I think the reason we love them so much is purely because they are the best things on television. So much television these days is taken up with Pop Factor and X Idol or Big Celebrity's Brother Get Me Out Of Here that it's increasingly hard to find a reason to turn the television on.
Life in Cold Blood, The Blue Planet and Planet Earth are programmes which have been the labour of love for those of worked on them for many years (7 in the case of The Blue Planet). It comes across in what we see. Passion, love and dedication make for good television.