[Ggdf]

Can anyone please help me with this question? I don't understand how to answer it!

Please see the image in the link below first:

http://i1088.photobucket.com/albums/...lationship.jpg

The question is:

How many million years ago did D.melanogaster and D.pseudoobscura last share a common ancestor?

The answer in the mark scheme is 26 million years ago. However, I've no idea how you work it out!

If anyone can help me I'd be really appreciative!

[Heyimdec]

Are you sure you have all the question there?

I remember something similar to this question and it showed you a genetic 'tree' almost with links to common ancestry.

Which BIOL2 paper is it?

[KMLeeson]

I agree, it was on the January 2011 paper and it had the lines drawn on the paper. You must of got a bad copy. Good luck for tomorrow.

[Ggdf]

Hey Thanks very much for your replies and good wishes! I thought there had to be something missing; I'm glad you agree too! It was Jan 2011. I was getting worried that this was some kind of new-age chart that I didn't know how to interpret, lol .

Wishing you all the very best of luck with unit 2 tomorrow if you're taking it! Best wishes for all your exams!

[SHepw]

I'm doing the paper by reading it from the aqa website pdf thing and even on there it has no other lines, its just a chart with no data on?