Hunks can eliminate their rivals in direct confrontations. But 'shorties' can sneak faster in a woman's world: nature too comes with its example of sex machine dwarfs. At least in the already dwarf world of the beetles.
A team led by University of Kentucky evolutionary biologist Charles Fox wanted to see if little males
might outcompete the buffs in the mating race.
For example, "smaller males are presumably better flyers because it's easier for them to fly," Fox explained.
The team studied seed beetles (Stator limbatus), growing eight lineages of the insects, some large, some small. The males were let loose in a large chamber with females on the other side. The smaller males took off faster and got to the females more quickly than larger rivals, "presumably allowing them to mate more quickly and more often," Fox said.
Other examples of smaller males being in advantage in the sex race are seen in shorebirds, "where the birds compete with acrobatic flights, smaller males are favored as they can turn faster in displays. These findings could help explain why males of most insects are smaller than females," he said.
Moreover, the team discovered that smaller males were greatly advantaged in their race towards the females at cooler temperatures.
"Perhaps smaller beetles warmed up faster because there was less weight for their bodies to heat up, allowing faster take-offs. Or the muscles of larger beetles might have found it harder to move their extra weight in the cold." suggested Fox.
Another recent research made on seed beetles found a weird and extreme sex war: their penises are extremely spiny, helping in anchoring the males inside the females. The females counteract by growing genitals that are even tougher than the spinier male genitals. Some seed beetle species display over 100 spikes on their penises.