There have been several theories as to why ursids rub their backs on trees. Some think that it's a means of marking territories. Another, more recent, claim is that bears actually do this as a means of establishing a baseline "scent similarity." This way, if a new bear enters the territory of another bear there will be less of a chance for conflict because the intruder may think something to the effect of, "Hey, I recognize that smell! This must be his territory. I should probably not fight this dude because he has a lot invested in this particular area of land."* Alternatively, there is the scenario as described in the video; I feel particularly inclined to cast my lot with this theory.
As a reminder, we will be meeting at 4:00 pm tomorrow (Wednesday, Jan. 21) at One World Cafe to discuss chapter one of the Origin. In honor of this meeting, I thought I'd post this video of a really cool "accidental experiment" with silver foxes in Russia:
Please go to that site and fill in the boxes for times that you CAN attend, and we'll try to find something that works for everyone. I'm also adding this link to the blog. Our first meeting will be next week (Jan. 19-23, whenever works for the schedule), so please "do the doodle" fast.
Jan. 19 - I. Variation under domestication Jan. 26 - II. Variation under nature Feb. 2 - III. Struggle for existence Feb. 9 - IV. Natural selection Feb. 16 - V. Laws of variation Feb. 23 - VI. Difficulties on theory March 2 - VII. Instinct March 9 - VIII. Hybridism March 16 - Spring Break March 23 - IX. On the imperfection of the geological record March 30 - X. On the geological succession of organic beings April 6 - XI. Geographical distribution April 13 - XII. Geographical distribution continued April 20 - XIII. Mutual affinities of organic beings: morphology: embryology: rudimentary organs April 27 - XIV. Recapitulation and conclusion
I have created this blog as a forum for continuing discussions on Darwin to complement our discussions in class. Please use it! As you will learn, extensive correspondence is one of the hallmarks of Darwin's attitude towards science; this can be the modern version.
You can participate in the following ways:
1. Making posts; you will have to register with blogger.com and get added to the contributor list for this blog (I will do that).
2. Make comments, either signed or anonymous is ok.
3. Follow the blog. You can set things up to get email alerts when there are new things posted, for example.