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Middleton talks genetic diversion

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Ingrid Rodriguez
Staff Writer

Kevin Middleton, associate professor of biology at Cal State San Bernardino, presented three research topics to explain the working physiology of animals.

His research looked at lab mice, penguin feathers and bat bones.

Middleton used an example of a bicycle’s construction by saying that the similar materials can be put together to make something different but still function as a bicycle.

“The way a structure works is a form of both of these things…what the material is and how it’s put together,” Middleton said.

The first out of three studies that Middleton presented was a project on mice he began 20 years ago. He studied the skeletal physiology in high activity mice.

Middleton said 600 mice get tested each generation and get bred unless the mice are brothers or sisters.

“Without genetic diversion you won’t get evolution,” Middleton said.

He also said that it varies on the mouse. It is more likely for a mouse to be a high activity runner if both of his parents were runners.

“If you give mice a running wheel, they’ll run,” Middleton said.

One of the experiments that Middleton conducted was measuring how much mice run by counting how many times the wheel goes around.

Both types of mice weigh 1.05 ounces and run each night but the controlled mice run 0.78 miles whereas high activity mice run 9.75 miles.

He analyzes the females separately from the males because he said that female mice run 20 percent more than the males.

Middleton showed a picture of a mutation in high activity mice called the mini-muscle phenotype.

The muscle of a mutated mouse was brighter when compared to that of a controlled mouse. Those affected by the mutation are also much smaller.

“In order to run…we think these mice have altered their posture,” Middleton said.

“(It was interesting) looking at how an animal was able to cope with doing multiple things at once,” assistant professor of biology Heidy Contreras said.

“For example, those rats that run really fast, they’ve changed their anatomy, which means they might have changed their physiology as well.”

Middleton then talked about penguins and feather bending.

He studied Inkayacu Paracasensis, which was known as the “water emperor.” He was a penguin who lived in Peru and was 58.5 inches tall.

“It’s big and it’s old but the other cool thing about it is it has preserved feathers,” Middleton said.

He said that black feathers are more durable but the Inkayacu Paracasensis had reddish brown and gray feathers. This is what Middleton believes was the cause for their larger size.

“Why did Inkayacu Paracasensis have giant feathers versus others,” junior biology major Diego Villalobos said.

Villalobos said that Middleton’s work raises questions and Contreras added that this is how science moves forward.

The last of his research he discussed was about bats and their bones.

The Pteropus Vampyrus has a two-meter wing span and his metacarpals make up half of his wing.

The bones located in its wing bend as it flies. Middleton said that the bats bones are incredibly flexible.

“Obviously they’re not breaking their wings,” Middleton said. “So, it must work.”

To conclude his lecture, Middleton mentioned he will continue to study these three subjects.

“(He researches) life in the past using math and biology leading into future research,” Villalobos said.

Ingrid Rodriguez can be reached at

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