The male of this species can be two to three times the mass of the female, but the females seem to be in control of the genetic destiny. (Credit: Photo by Joseph Mehling '69)
Two scientists from Dartmouth studied the brown anole lizards. Brown anole lizards choose different size males for breeding. They produce more sons with the sperm of larger lizards. For daughters they use the sperm of smaller male lizards. This is believed to be done to ensure that the sons inherit the larger size gene which is a great key in survival.
Two scientists from Dartmouth studied the brown anole lizards. Brown anole lizards choose different size males for breeding. They produce more sons with the sperm of larger lizards. For daughters they use the sperm of smaller male lizards. This is believed to be done to ensure that the sons inherit the larger size gene which is a great key in survival.
Bob Cox the lead author on the paper and a post doctoral researcher at Dartmouth in Hanover, N.H."This species has figured out a clever way to pass on genes with gender-specific effects on fitness, usually, when natural selection pulls genes in different directions for each gender, the species faces an evolutionary dilemma. But these lizards have solved this puzzle, they've figured out how to get the right genes into the right gender."
When the choose of small males is greater than the choose large males females grow more numerous than males. The mother can manipulate the gender of their offspring. Over an eight month period studied showed that males with the genes from the father survived when compared to those with genes from small fathers. For the females this study showed no difference. The larger genes are most important for the survival rate of males. Females prefer to mate with larger males than small males.
The next big question is how does the female lizards control the gender of their offspring. More studies will be conducted to study this and to see what "mechanisms involved in this most fundamental of all evolutionary processes, the struggle to pass on advantages genetic material."
That's preaty interesting. Not only on a base biological level. The very act of 'selecting' a mate, for whatever reason, suggests a kind of intelegence, whether instinctual or cognitive, that we don't esually attribute to lower level species like retiles.
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