jump to navigation

Watch where you go: see where you went May 28, 2008

Posted by David Corney in Uncategorized.


Just a quick one… I just read Leo Peichl’s excellent 2005 review of the diversity of mammalian photoreceptors, and it’s a goldmine of fascinating detail, full of examples and interesting speculation. It summarises his and many other people’s findings over the years, covering classes of photoreceptor, their distribution on the retina, possible evolutionary pathways, and so on. One item stood out though. Apparently, most rodents can see ultraviolet (UV) light (as, incidentally, can plenty of non-mammalian species). It’s not clear why though, given that plenty of rodents are nocturnal and plenty are diurnal: why should they see UV? One suggestion is that rodent urine is highly UV-reflective. As Peichl says, “…rodents might profit from seeing their scent marks in addition to smelling them.”

Which is perhaps bizarre, but makes sense. But how did this evolve? Wouldn’t it be easier to develop say, coloured urine, if seeing it really helps? I think some birds can see UV, so it can’t be a camouflage issue. And what about the first rat to see his own pee?

“Look everyone! I can see where I peed yesterday!”

“You been eating that fermented cheese again, Barry?”

Peichl, L. (2005). Diversity of mammalian photoreceptor properties: Adaptations to habitat and lifestyle?. The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology, 287A(1), 1001-1012. DOI: 10.1002/ar.a.20262



1. www.fod.Ac.Cr - January 20, 2013

Have you ever considered about including a little bit more than just your articles?
I mean, what you say is fundamental and all. However think of if you added some
great photos or video clips to give your posts more,
“pop”! Your content is excellent but with
images and clips, this blog could undeniably be one
of the very best in its niche. Amazing blog!

2. http://yahoo.com - February 10, 2013

Thanks for the post for posting “Watch where you go:
see where you went V1”. Imay really be back for
more reading through and writing comments shortly.

With thanks, Franklyn

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s