Animal Life, 10:00 MWF
May 2, 1998
"How Females Choose Their Mates"
By Lee Alan Dugatkin and Jean-Guy J. Godin
People often think of choosing their mate as a task or something that takes a lot of thought. What they dont realize is that a good deal of the decision making may acutually be done without us knowing. This article describes in detail the many ways that animals are attracted to each other and how they choose their mate. Many of the choices made are thought to be and described in this article as genetic. Dugatkin and Godin state that females are the choosier sex when it comes to picking a mate. Their reasons for this are first, males produce many sperm at one time while females on average produce one. Therefore they invest much more in each gamete. Because females are generally limited in their production of eggs and males arent the males tend to compete for female attention.
Charles Darwin was the first to purpose that competition plays a large role in reproductive success. He believed that any traits that were beneficial for attracting a mate, survival of the offspring, or showing dominance were passed on from one generation to the next. The way this was explained is that the most successful male would mate the most therefor his offspring would have the same traits as him and those characteristics would become dominate in that species.
From the article we can conclude that there are two basic ways that female animals choose their mates. First, they may choose their mate because of some specific feature that either stands out or is known to be beneficial. The article tells us about guppies (Poecilia reticulata) and how females are more attracted to the brightly orange colored males. The more subtle orange colored the less likely they are to be chosen over other male guppies. Often bright colors or flashy physical features demonstrate dominance or superiority. This article presents an experiment done with swordtails (Xiphophorus helleri) that shows the effects of "peer pressure" in choosing a mate.It was found that female swordtails prefer males with long "swords" on their hind fins. The researcher took a closely related species (the platyfish), which doesnt have swords at all, and placed artificial swords on them. They found that the female swordtails were immediately attracted to these platyfish. This proves that genetic characteristics are a determining factor. The other way we know that females choose their mates is by copying their peers. An experiment done with black grouse (Tetrao tetrix) demonstrates this. To conduct the experiment they placed stuffed dummies near certain males to represent interested females. The researchers showed that "female grouse mated preferentially with the male that appeared to have other females in his territory" (Dugatkin, Godin, p.5).
We have found that there are some explainations for how we choose our mates but after all is said in done there is still a great deal of unknown information. We cant determine why some species strives while others are falling. There is often no explaination of why we find on thing attracative and the next repulsive. Although there are many unknowns these experiments and articles bring us closer and closer to truth.
Taken from an article written by Lee Alan Dugatkin and Jean-Guy J. Godin in Scienfitic America
The articles address is: http://www.sciam.com/1998/0498issue/0498dugatkin.html