possible tfamily trees from four animals
September 10, 2013 at 6:55 am #17522
I am reading The Blind Watchmaker by Richard Dawkins.
in the chapter entitled The One True Tree of Life, when he is explaining a Cladist’s practice of taxonomy based on bifurcating branching trees, he states:
‘Each of the fifteen possible trees uniting four animals represents a possible family tree. Of all the fifteen conceivable family trees uniting four animals, one and only one must be the correct one. The history of the animals’ ancestors really did happen, in the world. There are fifteen possible histories, if we make the assumption that all branches are two-way branchings.’
I tried a few ways to ‘diagram’ the fifteen possible family trees uniting the four animals but I couldn’t. I came up with 12, 22 and 24 possible trees.
I am WAAAAY not a biologist – I don’t think I even took it in school – and don’t know anything about biology AT ALL except what I’ve learned from this book, but I’m really enjoying the book and I just became very curious about the fifteen trees.
I don’t know how one would show a diagram in a thread like this, but can anyone help me figure out the fifteen trees?
September 10, 2013 at 3:35 pm #114347JackBeanParticipant
how could you end up with three different numbers?
September 10, 2013 at 4:01 pm #114350
Thank you Jack-Bean for your reply.
I was trying different approaches to figure out the fifteen possible trees – with no knowledge of biology, cladism or taxonomy, only what I’ve read in The Blind Watchmaker.
I was looking at them again after I posted this and I think that I came closest with the approach where I got twelve, kind of bascially using the same tree but changing the animals at the end of each branch. If that was even remotely close, I just can’t figure out the last three trees.
September 10, 2013 at 4:41 pm #114351JackBeanParticipant
can you somehow scan it or draw in Paint or something? I can think of only 4 trees with 4 animals.
September 10, 2013 at 7:06 pm #114352
I’ve made a diagram in Word and explained my reasoning as best I can.
except that I tried to upload it as an attachment but it keeps saying that the extension xxx ia not allowed, xxx being one of eight or so types I tried: word, rtf, word 97-2003, mht, html etc.
do you know a format that it will accept to upload? I don’t know of any more I can try. I have a printer here and it may be able to scan, but I’ve never tried it and who knows if it would accept the scanned format, whatever that might be.
I don’t see a HELP button anywhere to see if it specifies allowed file types, but I’ll check around after I submit.
I seem to run in to these sorts of technical issues with some frequency.
September 10, 2013 at 7:14 pm #114353
well, there’s this tab at the top that says ‘Share your work’ – and it specified all of the file types which included a pdf so I uploaded it but to where I have no idea. it said that it was uploaded successfully and would be reviewed but I didn’t make any comments so they’ll probably just file 19 it.
isn’t this fun?
September 10, 2013 at 7:20 pm #114354
then I went to faqs and found this:
Why can’t I add attachments?
Attachment permissions are granted on a per forum, per group, or per user basis. The board administrator may not have allowed attachments to be added for the specific forum you are posting in, or perhaps only certain groups can post attachments. Contact the board administrator if you are unsure about why you are unable to add attachments.
but if it has an upload attachment tab at the bottom of the page, then wouldn’t that indicate that attachments are allowed for the forum?
are you wondering if i have nothing better to do with my time?
September 11, 2013 at 3:34 pm #114357
if you’re still interested, In uploaded the pdf to Dropbox with which I’m not familiar but was suggested to me and I think that you can see it there.
the link to it is:
https://www.dropbox.com/s/wv4ewm1kno0zi … trees.docx
I think you’ll be able to see it there.
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