Cleaning Up


Keeping your abode tidy and clean is a continuing chore for most of us. Sharing accommodation with others puts even more pressure on that activity if social harmony and health is to be maintained. The bigger the community is, the bigger the job. This is true for  species other than us.

Many insects have evolved to live in very large communities, which could arguably be referred to as well run. But picture living in one of these. What would you use for cleaning materials? No vacuum cleaners, not even a duster, just your tongue and teeth. Not a very appetizing thought.

So if you have a choice, it would be wise to choose to be a social spider mite (Stigmaeopsis longus). These little beasts use sticky dusters to clean up. The females use freshly spun silk threads to polish the eggs, to dust the nest and clean up the crap. The subject is to be reported by Kanazawa et al in The Proceedings of the Royal society (1) next month.

As I use my sticky roller to pick up cat hair from the couch, or my electrostatic duster to pick up dust from the bookcases, I wonder if we couldn’t persuade some social spider mites to move in and help out. With a robo-vacuum cleaner quietly charging in the corner, I would be all set.


  1. M. Kanazawa, K. Sahara and Y. Saito, Proc. R. Soc. B, 7 June 2011 vol. 278 no. 1712 1653-1660

Drawing the Short Straw


Which box do you check in life’s happiness questionnaire? “Very satisfied,” "very dissatisfied,” or something in between? “It depends on the deal that I got,” you may be saying. Well, yes, it does depend somewhat on the deal that you were handed at birth. About thirty to fifty percent you can blame on your parents, if studies on twins are correct.

For some time now we have had studies indicating that our genetic inheritance of the serotonin transporter gene, solute carrier family 6, member 4 (SLC6A4), or 5-hydroxytryptamine transporter: 5-HTT is the key to about twenty percent. (We can put the rest down to weather and taxes.) Serotonin is the happiness hormone and 5-HTT helps carry it, around distributing its largess to our satisfaction.

 5-HTT comes in long and short variations, and if you’re asking, “Please, sir, can I have some more?” the arrival of a long train would be better than a short one. Of course you get one from each parent, so you can have two long ones, two short or a long and a short. If you are only half as happy as you think you should be, ask which one short-changed you.

The latest metastudy by De Neve, which is reported in today’s Guardian newspaper (1), was of a large group of US citizens. It adds to the body of evidence that the “glass half full” attitude is partly genetic. 

Serotonin also plays a role in cognitive functions such as memory and learning. Ironically it also occurs in some insect venoms and is the cause of the pain when bitten. Maybe just the threat of serotonin injections would make our kids pay attention and learn more in school.



  1. http://www.guardian.co.uk/science/2011/may/06/happiness-gene-long-short-versions

In The Heat Of The Moment


Sitting outside on warm summer evenings is often accompanied by the sound of hands slapping flesh as we respond to the unwelcome embrace of mosquitoes. Mosquitoes dine on nectar for their bodily sustenance, but the females amongst them crave blood to enable them to produce eggs. When they stick their proboscis into your flesh, they inject saliva to prevent clotting. It incidentally has antimicrobial properties to inhibit bacterial growth in their nectar meals.

The body temperature of our active mosquitoes is around 70°F and that gives them a problem. When they chomp down on us, they are getting a hot meal at 98°F. Remember that they are not sipping but gulping, so they have a big spike in body temperature which is liable to mess up their body proteins. Denlinger et al of Ohio State U (1) have reported on how they handle this problem. They express a particular heat shock protein that protects their proteins from the stress caused by the sudden temperature rise in their gut.

Without this protection, their ability to digest their meal is significantly diminished, as is their ability to produce eggs. Should they decide to dine on cold-blooded amphibians, this protective protein isn’t produced. Bed bugs also use this strategy for tackling hot meals.

Being a mosquito is not such an easy life it seems. Sneaking past our defenses to get through our thick hide and get a bellyful is not the end of their problem.


http://researchnews.osu.edu/archive/hotblood.htm

Just Being Social


Sheep are often used as examples of creatures following social information clues without question. Of course, most group-living species benefit from the rapid spread of such information, indeed their survival may depend on it. Social information is the big reason for group-living in most cases. We humans have become much more sophisticated than sheep. We don’t baa at each other, most of the time anyway. These days we Tweet, and re-Tweet, making the spread infectious, and the use of #-tags takes the whole thing viral in no time.

In between Tweets, we put our smartphones to our ears in a vain attempt to warm up our brains with the microwave emissions, and then we revert to the old stand by – do what our neighbors are doing – the safe option. Or is it?

Faria, Krause and Krause have been watching pedestrians cross the road. Why? Probably for the same reason as the chicken. Their paper: “Collective Behavior in Road Crossing Pedestrians: The Role of Social Information” (1) makes interesting reading.

They note that if one person goes, the people next to them can’t hold out and go too. Manifest destiny I guess. We are about twice as likely to go across the big divide as to stay on the safe edge of excitement. In line with their testosterone levels, males are more likely to go for it than females.

There are some people who start, but their courage fails and they return to the safety of the curb. Interestingly, these adventurers tended to be members of a group. They clearly had too much discussion going on, and had to comer back for a board meeting.

There were two important conclusions drawn from this study:
  1. That social information induced some people to make the wrong decision in their timing to make the crossing adventure.
  2. That the small benefit in waiting time was gained at the cost of a higher risk of injury, thus the making the social information of dubious value.


   
  1. Behavioral Ecology (2010) 21(6): 1236-1242 first published online September 9, 2010doi:10.1093/beheco/arq141

Tiring Day


A major problem that we have all experienced at sometime is the avoidance of catching a yawning jag when listening to a lecture after a good lunch or dinner. There are currently three ideas battling it out to explain our plight when someone else yawns first. The first is that it is simply a fixed action pattern that is triggered when we see someone else yawn. The other explanations require us to either feel empathy with the other person or that we can’t help ourselves, but we just have to mimic the action. These last two are indicative of some form of complex social process between the yawner and the yawnee.

Wilkinson et al (1, 2) have just published a study in which they aimed to understand this better. They chose a group of seven subjects whose social interactions were on a fairly basic and phlegmatic level. They were red-footed tortoises that knew how to behave in a proper scientific study. Yawning though, was not something they worked on previously. Alexandra was taught to open her mouth in a yawn-like gape when she was shown a red card. A conditioned reflex shared with most of our professional footballers.

A series of experiments with two girls, Wilhelmina and Moses (Oh dear!); a boy, Aldous; and three who they weren’t sure about called Quinn, Esme and Molly, were performed in which Alexandra was shown the red card in their presence and gaped in disbelief on cue.

Nobody yawned in response, so there was no contagion. Thus the fixed action pattern can be ruled out as a mechanism. Empathy and unconscious mimicry were already eliminated, as the species is not noted for rushing around showing too much empathy or strong social-group  interactions.


http://www.guardian.co.uk/education/2011/may/02/improbable-research-yawning-contagious-tortoise

http://www.actazool.org/site_media/onlinefirst/downloadable_file/2011/04/08/10

Socially Acceptable


In our daily meanderings we interact with people on a wide range of levels. Some of those interactions may be important to our well being – a routine visit to our Doctor’s office, for example – or of no lasting importance at all, such as buying an ice cream on a sunny day at the beach. Which interactions do we remember? We can all quote a few examples of bad and good interactions, but what about the rest?

A new publication by Volstorf et al (1) has attempted to answer this question. They used a game in which two people can decide independently whether to cooperate with each other or to cheat on each other. It is known as the “Prisoner’s Dilemma” and has a format familiar to all of us who watch crime dramas on TV. If they both cooperate, they score high; if they both cheat, they score less well but if one cheats, he/she does very well and the cooperative one loses big time.

 Each player has a large number of interactions, and then they all assemble a week later and play again. They cannot remember each interaction, there were too many in a short time. The question is whom do they remember accurately – those who cooperated or those who cheated? Intuition or prejudice would lead us to hope that the cooperators would be remembered, but we would probably suspect that the cheaters would make the bigger impression. Given the opportunity, the temptation to play “tit-for-tat” is pretty strong even when we know we shouldn’t.

The good news is that our brains are too busy to get cluttered up with all that stuff.  If an individual had similar numbers of cheating or cooperative interactions, there was no selective action against those who had cheated them. The participants, who had very low numbers of interactions where they were cooperated with or were cheated, remembered that well and responded in like manner.

We remember the rare interactions best. The particularly good or the particularly bad service in a restaurant, for example. We take the usual good that we get everyday for granted.  It is departures from the norm that sticks, whether that norm that we have become used to is good or bad.  If we become used to a very high standard of performance, we get very sniffy if it doesn’t come up to snuff on some occasion. But the corollary is also true that we can get used to consistently bad interactions and be wonderfully grateful when we get a mediocre one instead of the plain bad that we have come to accept.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0018945#pone.0018945

What Goes Around, Comes Around


A recent NPR blog by Adam Cole (1) draws our attention to some recent studies on genotyping the leprosy bacteria. Every year in the US, about 150 people are diagnosed with leprosy. Its alternative name, Hansen’s disease doesn’t strike the same emotional chill, and it can now treated successfully by antibiotics. Texas and Louisiana are the states with the highest incidence. An interesting point brought out in the study is that geographically separated strains have recognizably different genotypes and that the people in Texas and Louisiana who have been infected must have been infected locally and not when visiting abroad.

In the 1970s, leprosy jumped from us to the armadillos. Now, about 1 armadillo in seven carry the bacteria. Armadillos are cool creatures. In fact their body temperature is nine degrees cooler and the bacteria like to chill out at the armadillo café. Now the Armadillos are returning the favor.

Tidying up road kill takes on a more exciting prospect. And my cooking experiments will not include those Texas favorites barbecued Armadillo and Armadillo Chili (recipe: http://www.yumyum.com/recipe.htm?ID=12105 ).


http://www.npr.org/blogs/health/2011/04/28/135740951/mysterious-leprosy-cases-linked-to-armadillos