When it comes to romance, humans are not as highly evolved as we might think.

When it gets right down to it, human attraction boils down to animal instincts, said Dwayne Meadows, Weber State University zoology assistant professor."When it comes to attracting the opposite sex, there is very little that separates humans from animals. Males are aggressive and compete for a mate, while females are more choosey," he said.

The basic difference is between sperm and eggs. Males produce a great deal of sperm while females produce far fewer eggs. Since more energy goes into making an egg, eggs are a hotter commodity. Females can be more se-lec-tive about whom they choose as mates, Meadows said.

People and animals rely on personal appearances and gift giving to attract mates, scientific research suggests.

Peacocks with the most eyespots on their tail feathers are more likely to win over a peahen. Deer or elk with the biggest horns are more attractive to their potential mates.

"These animal actions and characteristics are similar to a man or woman's attraction to the opposite sex based on the clothes they wear, the car they drive, financial status and physical appearance," Meadows said. "Many times these attributes are what initially spark a relationship between people."

Research also supports the idea that physical symmetry is pleasing to the animal eye.

Gifts help, too, Meadows said. Gifts help gain access to the opposite sex, which can foster courtship.

Take the female Mormon cricket. She selects a mate according to the amount of food offered by interested males.

The Australian male bowerbird builds a nest and surrounds it with flower petals and other natural ornaments.

"The only thing that makes humans different is that we base our mating on formal traditions such as dating, marriages and anniversaries," Meadows said.

Meadows cautions not to carry the comparisons too far. A sense of humor and personality can still influence human relationships.

But biologically speaking, it's still the female's call.