Sunday, October 21, 2012

We have just come to the end of a two-month drought on our island. We were very worried about the fire risk in the old-growth forest on the mountain. The first picture shows how the so-called Emerald Pool in the forest had shrunk to a puddle. But in our driveway, things were very different, as the second picture shows - our well continued to overflow, apparently being fed by an inexhaustible aquifer. 

So we were able to water our garden liberally throughout the drought, knowing that if we didn't use the water, it would just flow into the ocean.  An interesting contrast. From now on we have to persuade the excess water to flow into our creek, (which never dries up either).


Thursday, September 6, 2012

Correlation and Causation

These are not words most of us use every day (unless we are scientists, that is).

I recently read a fascinating news item telling me that people who had cataract operations were less likely to break their pelvis.

Now, one could spend time trying to find a physiological link between the replacement of cloudy lenses in the eye and increased strength of pelvic bone.

But a little thought will show us that once people can see better, they are less likely to trip and fall.

There is a strong correlation between these two events, but one does not physiologically cause the other.

The world is full of apparent links, some of them true, some not.

We were pretty sure that smoking caused lung disease, but because we could not do controlled experiments on people, it was much more difficult to come up with proof that one caused the other (though it accumulated eventually). Note however, that though people are not allowed to smoke on planes, Governments and private investors still reap huge profits from the sale of tobacco. Addictions are extremely difficult to cure. We don’t seem to know what causes gambling addiction, but it is another one that brings huge amounts of money into Government (and private) coffers. Makes one wonder if a real cure would be welcome, or whether enough research is being done into the causes.

We are now optimistic about ASA (acetyl salicylic acid) [sometimes called by the trade name of Aspirin] and its preventive effects on many important threats to our health – heart attacks, colon cancer and others. But we are not sure of these effects, partly because there are not enough truly scientific double blind studies behind the claims, and partly because people’s lifestyles are so diverse that it is almost impossible to unravel the effects of ASA from many other substances they take on board, or many other of their behaviours. Again, this is because we cannot do truly controlled experiments on people (they have to be the worst possible subjects!) and must wait for the truth to gradually become clear after innumerable studies seem to add up, and meta-analyses finally lead us to a reasonable conclusion.

We should always be cautious about accepting supposed causations that may just be correlations.

Monday, July 16, 2012

We have been compiling the fungi in John Dean Park for years, and have listed hundreds.  But the other day I found a new one - a leaf-curl fungus that attacks Poplar leaves.  The pictures tell the story:
the third is a photomicrograph I took of some of the asci, which cover the surface of the yellow areas of the leaves. Asci contain lots of yellow oil, which explains the colour. This is a very unusual ascomycete, in that it does not make any fruit bodies. Members of the same genus, Taphrina, cause peach leaf curl, a fairly serious disease.





Thursday, June 14, 2012

Geopora cooperi

On a recent mushroom foray in Washington State we found a wonderful fungus that shows evolution in action. We now know that underground truffles started out as cup fungi fruiting on the surface of the soil, then retreated below as the climate dried out. This fungus, Geopora cooperi, shows the process part of the way through. What was once a large cup fungus has folded in on itself and become like a ball of scrunched up newspaper (look at the first picture), with the spore-bearing surfaces on the inside, as the second picture shows.
I had never seen this before and it was an exciting discovery for a mycologist/evolutionist. If you are fascinated by natural history and biodiversity, as I am, this shows that you never run out of new things to see and wonder at.




Tuesday, May 29, 2012

Calypso Orchids

Recently, when walking on the mountain, I found some calypso orchids. These are supposed to be a sign that Spring is here, and morels are up. So I went to my little secret morel patch and found that they had indeed popped, almost overnight (there had been none the previous week). 








The photo shows a cluster of six, exactly as they were when I found them.
So I picked some, left some to propagate themselves, and we had a tasty dinner.
Delicious! This is one of very few mushrooms Laurie has any time for.




Thursday, April 19, 2012

Stormy Weather!

During a recent storm we were awoken at 4 am by a huge bang and a brilliant flash.
It wasn't thunder and lightning (which almost never happen here). No, our multi-trunked 70-foot tall poplar tree had blown down across our stream and into the park next door (picture 1), taking out our hydro pole on the way. Three days and one new pole later we got our power back.


Why did this happen? Looking at the aftermath, I noted that the hole where the roots had been was half full of water (picture 2). When we were able to cut up the main trunk, I saw extensive white rot at the base (right hand side of picture 3). So the fungi were largely to blame...







Tuesday, April 3, 2012

Dolphins!

It is an amazing experience to be lying flat in the water, and then have two dolphins come up from behind you and push with their noses, one on the sole of each foot, until you are projected forward and raised high in the air before they dump you.  This happened recently in Mexico to my twin granddaughters (who weigh about 60 pounds each), and to me (I weigh in at 145 pounds).  Somehow or other, the dolphins were able to communicate to each other exactly how hard each of them had to push to achieve the desired effect.  They did this successfully to eight people of varying heights and weights while we all watched, and never made a mistake.  I have no idea how they can synchronize their efforts so precisely - clever beasts indeed - or how they could be trained to do that.





                                         The picture shows Skylar just after being 'released'

Tuesday, February 7, 2012

Sand Dollars

We tend to think that sandy beaches are more or less sterile, but it isn't true. Life exists everywhere. During our walks along the gorgeous beach at Riviera Nayarit at low tide, we found Keyhole sand dollars. Those we have here on Vancouver Island have complete discs, with no holes, but those in Mexico have 5 slits through the disc. They move about slowly
just below the surface of the sand, and I could watch them sieving the sand through the slits
as they filtered it and the water for food particles. The trails they left were often quite amusing, because they had a little 'owl face' at the end, as you can see in some of the photos.
Or sometimes they looked a bit like an animal footprint. Their name is Mellita (not spelled like the coffee), and there are thousands of them, all along the shoreline.






Thursday, January 26, 2012

January 24, 2012

On the endless beach at Riviera Nayarit in December Laurie and I found clusters of turtle egg shells. We also came across a few wire mesh enclosures in which turtle eggs were clearly being incubated (each 'nest' was marked with a date). Eventually I unearthed the secret and got to participate in the action. These were Ridley’s turtles, which we had never seen before, and volunteers cruise the beach on ATVs every night looking for laying turtles. I got to go along on a bumpy ride with a volunteer by the name of Memo. We found a nesting turtle and stole her almost 100 eggs as she laid them. She, being busy, was quite unaware of this. After she had spent several minutes smoothing over the now empty nest, she headed for the water. We watched until she was back home in the ocean, then took the eggs away and dug a surrogate nest in one of the enclosures. The other end of the story comes at sunset every day, when the turtle people release hundreds of newly hatched babies on the beach, and they head into the surf.  I got two of my own to launch.