Showing posts with label evolution. Show all posts
Showing posts with label evolution. Show all posts

Friday, 1 March 2013

Plants and People

One thing I really love about working at Mount Royal is that I get to work with some really interesting people.  My colleague David Bird is teaching "Plants and People".  He's bringing into the class a lot of content that shows how agriculture was established. 

Until we were chatting in his office, I hadn't thought about how much we've worked against natural selection as we created our crop species.  I knew in principle how threshing worked, but hadn't thought it through until Dave showed me this video:

Here's what's so cool:  natural selection says that the seeds should detach easily so that the progeny can be distributed.  That's a successful strategy for a species.  And we consumers should want that as well - we don't want the chaff with our wheat.  But think about doing this on an industrial scale.  You're a farmer, and you've selected for wheat where the seeds come out easily.  But when you go to harvest, all the seeds fall off and get buried in the ground! 

So humans have ended up selecting for wheat that keeps the seeds intact, but force us to devise ways to sort out the food parts from the not-food parts.  Look how much work that was done by our ancestors!

Friday, 24 February 2012

Salps

I've always loved the diversity course I taught.  I was able to get really excited about the strange evolutionary connections between us and other creatures.

One of the most fascinating is the connection between the tunicates and us.  We're clearly vertebrates.  But roll back the evolutionary paths and we converge with a group that retained primitive characteristics.  They look like jellyfish - but are anything but!

Here's a video my friend Lex passed along showing examples of tunicates:

Monday, 12 December 2011

Spider silk

I can't think of a better way to demonstrate evolutionary descent and the importance of genetics on the formation of a protein as well as this presentation from Ted does.  My thanks to Linda for sharing this!


The letters of the amino acids are highlighted and beautifully illustrate what evolution has to work with to generate a huge array of "tools" for the spiders to use!