Professor Jonathan Losos explains evolutionary biology using cats
Jonathan Losos, professor and director of the Living Earth Collaborative, spoke on “The Science of Cats and the Future of Nature” in a talk co-hosted by the Washington University Alumni Association and the College of Arts & Sciences on Dec. 11 in Wrighton Hall.
Losos explained modern research on cats, such as the evolution of the meow and purr, the genetic origins of cats, and even research originating here at Washington University. He analyzed all these topics further in his recent book, “The Cat’s Meow: How Cats Evolved from the Savannah to Your Sofa,” and in his evolutionary biology course at WashU, The Science of Cats.
In his talk, Losos explained how cats rarely meow to each other, despite all 33 species of small cats having the capability to. Cats meowing to us, he said, was something they “picked up” during domestication.
“All small species of cats meow,” Losos said. “The domestic cat didn’t invent the meow, it just started using it to communicate with us.”
Losos analyzed research done on cat meows done by Cornell graduate and researcher Nicholas Nicastro.
“The housecat has actually altered its meow to make it more pleasing to us,” Losos said.
Further, while there is unfortunately “no uniform cat language” for humans to decipher, Losos said that cat owners tend to be able to distinguish their cat’s meows for, say, food or pleasure.
“Even though other people couldn’t tell you the context [of the meow], the person who lived with the cat was really quite good at it,” Losos said. “What seems to happen is that cats and the people they live with negotiate a private language.”
Kaitlyn Hersch, an alumnus of the University, was particularly fascinated by the ability of a cat and its human to develop exclusive communication.
“I liked that each human and cat kind of make their own language with each other that no one else could really understand,” Hersch said.
However, meows are not the only sound these critters make — all small species of cats also purr. Losos recounted an experiment by British behaviorist Karen McComb which recorded these purrs. According to Losos and McComb, the purr can be separated into two types: a contented purr and soliciting purr.
“[McComb] played [recordings of] these purrs to people and asked them ‘Which do you like more?’ and far and away they liked the contentment purr more,” Losos explained.
Audio graphs of these purrs revealed that the solicitation purr contained a low frequency peak that happens to be the same frequency as a crying baby.
“[McComb’s] argument was that humans are innately attuned to the sound of a baby crying; that gets our attention very effectively,” Losos said. “So her argument was that cats have evolved to basically exploit our sensory system, to use the sound to get our attention, to purr when they want our attention.”
Class of 2010 graduate Greg Shmulevich said that overall Losos clearly spoke with “passion.” Shmulevich was particularly focused on how cats exploit human’s sensory systems.
“It seems like they’re really smart in how they try to manipulate it and sound like babies,” Shmulevich said. “I would think the theory that the meow and its higher pitch more resembles the baby trying to get attention.”
Another unique facet of domestic cats is that they are the only cat species, besides lions, to raise their tails to communicate friendliness, according to Losos.
“Domestic cats are thought to be aloof loners [like most other species of cats], but that’s not correct,” Losos said. “In some places, unknown outdoor cats occur at very high density. It turns out, in those places, those colonies formed into social groups that are very similar to lion prides.”
Ever the evolutionary biologist, Losos next revealed that, through Oxford graduate Dr. Carlos Driscoll’s traveling, sampling, and DNA analysis, the domestic cat’s origin is clear.
“[The domestic cat is] clearly descended from the North African Wildcat; their DNA is barely different,” Losos said.
While the exact location and time the cat was domesticated is unknown, there are plenty of theories, ranging from a gravesite 9500 years ago in Cyprus, to millions of cat-mummies and other domestic cat depictions made 3500 years ago in Egypt. Losos made sure to emphasize the difference between taming a cat and domesticating them.
“Domesticated [animals] have had genetic changes, they have evolved,” Losos said. “A tame animal is just a wild animal that you have treated nicely, that will hang out with you and not be too bad.”
Through vikings, the silk road, and the Roman Empire, cats have spread throughout the world, with there being close to one billion domestic cats today. With our worldwide love for these creatures, it is no surprise that, as with many animals, we are studying their genome.
“I’m proud to say that this work actually originated right here at Washington University,” Losos said. “The first cat genome to be sequenced was in 2014, and the project was led by researchers at the medical school here.”
This research has since moved to the University of Missouri under Dr. Leslie Lyons, and has had significant success, including uncovering the mutation causing the common Polycystic Kidney Disease, which abated its spread.
While genome sequencing has moved, Losos continues WashU’s feline legacy by studying cat coloration, specifically in Australia, to measure the evolution of the domestic cat.
“Cats in different environments are evolving different colors,” Losos explained. “This is very exciting because it indicates that [domestic cats] are diverging evolutionarily, so it makes it reasonable to look at more complicated…physiological traits.”
Many cat-loving alumni and students attended the event, and it was received positively. Virginia Hayden, a former engineering department employee at the University, described the talk as “very informative.”
“I just might [buy Losos’ book],” Hayden said. “We would come to another lecture.”
Losos was confident that there will be domestic cats around to research for a very long time.
“Eventually humans will stop destroying the environment,” Losos said. “It will happen eventually. There are many cats, species of all kinds, that we hope will survive, but will there be tigers or ocelots? Who knows. One species we know will be around for sure, though, is the domestic cat. They certainly will be the ancestors of the cats of the future.”