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Parental Favoritism

Oh..... the woes I have to tell from being the middle child. I often joke that I received less love because I wasn't the oldest..and I'm not the baby, playing into my no one loves me syndrome. Well, that may all be in my head...but the fact that it happens in nature is not. I will keep my complaints for Oprah but tell you about a few species in which favoritism does occur.

As we all know, everything must fight for resources. For humans, it is jobs, food, land, etc. It is not much different for animals in natural settings. One such case occurs in the Brown Booby(as well as many others) ..and no I didn't make up the name. Here we see such occurrences that some parents may permit certain offspring to harm their siblings. Siblings fight for food that their parents bring back to the nest; therefore, individuals that become dominant in the brood are at an advantage to remove competition (i.e., siblings). They may do this by bludgeoning rival offspring or by pushing them out of the nest to die (siblicide). So how does this increase the fitness of the parents? Well, that is where this behavior gets really doesn't. Natural selection acts in many ways. So who does this benefit? The surviving offspring. This is clearly an advantage to the dominant sibling and this is a clear case where the fitness interests of the parents clashes with the fitness interests of the offspring. The moral of the story...not everything is as simple as it seems..and if you live in a nice to your siblings.

For more examples on this topic, you may look up The Great Egret and a very interesting article on Hyenas which may rip each other apart as newborns. For all UK may be interested to know that two of our Ecologists: Westneat and Sargent are contributors to this topic!

1. The Evolution of Parental Care by Timothy Clutton-Brock
2. Westneat, D.F and R.C. Sargent 1996. Sex and Parenting: The effects of sexual conflict and parentage on parental strategies. Trends in Ecology and Evolution


posted by Sonya @ 12/18/2006 07:14:00 PM,


At December 18, 2006 at 7:53 PM, Blogger Sakshi said...

Woo hoo.. Go FFF!!!!
You need to cut your sugar intake in half.. Prolific blogging :P
But I did not know about the brown boobies (*sniggers*)
Amazing how natural selection has managed to find a balance between dominant sibling Vs. Parental fitness. Has anybody looked at aggresive behaviour genes in these critters? Or hormone levels?

At December 19, 2006 at 11:28 AM, Anonymous sameera said...

Wow Sonya. Its wonderful how natural selection work.

At November 3, 2010 at 3:31 PM, Anonymous Anonymous said...



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