Divorce of a Lizard

The phrase "in sickness and in health" is commonly included in many marriage vows, but may not be the finest evolutionary strategy for many monogamous species. Shingleback skinks (Tiliqua rugosa) are usually quite the adorable monogamous lizard; some pairs have been found to reunite to mate for over 20 years in a row. This puzzled behavioral ecologists, because unlike other monogamous species (like migrating birds and humans), monogamous reptilians don't partake in childrearing. They questioned what the fitness advantage of monogamy could be. A long term study on parasites of the shingleback could be their answer! It found that males were less likely to retain their previous monogamous partner if their tick load was higher.  From a parasitic perspective, having a monogamous pair makes a lot of sense, because pairs with low infection levels are less likely to become infected if they remain with the same partner. Alas, this lizard "marriage" only remains "in health"; when the male gets too many ticks, the fitness advantage is lost, and so his partner!

If you wanna learn more about this study and rad shingleback skinks:   https://link.springer.com/content/pdf/10.1007%2Fs00442-005-0224-z.pdf

Fungus amongus (or at least among ants)

Here's a recent post from NPR on  'Zombie' Ants And The Fungus That Saves Them",  relevant to John's lecture on crazy fungi.

"In the current edition of the journal PLoS ONE, an international research team led by David Hughes of Penn State University reports that they've found the fungus that allows an ant colony to survive infestations by a "zombie-ant fungus, which invades an ant's brain and causes it to march to its death at a mass grave near the ant colony, where the fungus spores erupt out of the ant's head."

"In a case where biology is stranger than fiction, the parasite of the zombie-ant fungus is itself a fungus — a hyperparasitic fungus that specializes in attacking the parasite that turns the ants into zombies," Hughes said."

In Science Daily, too.  The article will be published shortly in Plos One, but in the meantime here is a link to David Hughes website to learn more about what he is researching.

The carpenter ant in the picture on the right (genus Campanotus) has fallen victim to parasitic fungi of the genus Cordyceps, which manipulate the behaviour of their host in order to increase their own chances of reproducing. The spores of the fungus attach themselves to the external surface of the ant, where they germinate. They then enter the ant’s body through the tracheae via holes in the exoskeleton called spiracles. Fine fungal filaments called mycelia then start to grow inside the ant’s body cavity, absorbing the host’s soft tissues but avoiding its vital organs.


When the fungus is ready to sporulate, the mycelia grow into the ant’s brain. The fungus then produces chemicals which act on the host’s brain and alter its perception of pheromones. This causes the ant to climb a plant and, upon reaching the top, to clamp its mandibles around a leaf or leaf stem, thus securing it firmly to what will be its final resting place.


The fungus then devours the ant’s brain, killing the host. The fruiting bodies of the fungus sprout from the ant’s head, through gaps in the joints of the exoskeleton. Once mature, the fruiting bodies burst, releasing clusters of capsules into the air. These in turn explode on their descent, spreading airborne spores over the surrounding area. These spores then infect other ants,completing the life cycle of the fungus. Depending on the type of fungus and the number of infecting spores, death of an infected insect takes between 4-10 days.


Quoted from (click link to learn more): http://neurophilosophy.wordpress.com/2006/11/20/brainwashed-by-a-parasite/