Well that seemed like an interesting title for a lecture.  It would provide an evening’s diversion.  I went along.  I think the Department of Zoology turned up in droves.  Different selection of people to those of the Humanities lectures I usually attend.  I wonder if anyone has done a taxonomy of the departments of the University and its residents.  The lecture was a function to present Pr Robert Poulin was a medal for distinguished research.  The general public was welcome.  I was welcome.

Pr Robert Poulin is a French Canadian who has lived in New Zealand for a long time.  His accent is clear and interesting.  Very early on he moved from studying fish to studying parasites on the fish.  They interested him more.  I remember when the Irish comedian Dave Allen interviewed a member who studied fleas.  It made him scratchy.  I noticed the same affect.

Parasites are the uninvited guests at the table.  Despite numbering about half the known species on earth they have been dismissed in the past as a subject for study.  I think this is changing.  Even I have heard of toxoplasma.  Pr Poulin is a leader in the field, or possibly he has managed to infest himself in a number of his colleagues.

Marine parasites are interesting.  They colonise an animal like a snail and convert it into a parasite-cloning factory.  Some of them in the colony act as breeders, others as soldiers to protect the colony from rival parasites.  When they are ready they may migrate to another host that is more likely to be eaten by an ecology’s top predators where their eggs will pass from for another generation.  In an ecology the parasites may number the same biomass equalled only by the top predators.  They are very successful.

Knowing now how successful parasites are for making hosts to be prey for their final hosts I’m now wondering about the food in Lewis Carroll’s Alice in Wonderland.  Eat me!  Drink me!  Any food that advertises itself like that is potentially suspect and parasitic!

The connections that parasites make in an environment’s food-web make it more complex than previously expected.  Up to one quarter to three quarters of the links in an environment’s food-web involve parasites.  They increase the biomass and diversity of an environment and play an important role in stabilizing food-webs.  They provide the connection.  I would have liked if this was explored further and explained with examples as I am unfamiliar with how this happens.

Humans are making an impact on parasites in the environment.  Both climate change increasing the temperature of the environment, even by a small degree, and the concentration of herbicides are increasing parasitic populations.  This is a problem for host species and could lead to the death of species in many environments.

If you have read this far, are you feeling scratchy too?

Parasite Factory!

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