Learn how organisms cope with environmental challenges

Nadia Singh

When the environment presents challenges, some organisms respond in an interesting way: They produce more genetically diverse offspring than they would under ordinary environmental conditions.

That’s one of the key takeaways from research conducted in the lab of Nadia Singh, an associate professor in the Department of Biology and the Institute of Ecology and Evolution. The idea is that by producing a genetically diverse array of offspring, mothers may increase the chance that at least some of her offspring survive.

“From an evolutionary perspective, it’s really interesting because it’s this kind of bet-hedging strategy,” Singh said. “When (stuff) gets real, the idea is, let’s make everything look really different and maybe something has a chance of making it.”

Singh will discuss the phenomenon and her own research examining the genetic exchange that takes place during the process of making gametes — sperm and eggs — during a Sept. 25 Quack Chats pub talk titled “Don’t Put All Your Eggs in One Basket: Why Organisms Diversify Their Offspring in Response to Stress.” The talk begins at 6 p.m. at the Downtown Athletic Club ballroom, 999 Willamette St. in Eugene.

In her talk, Singh will detail the genetic exchange process, known as recombination, which varies from individual to individual, from population to population, from species to species and in response to environmental conditions. She will talk about her own research involving fruit flies and explain what researchers are learning by examining the effects of stress on recombination and the consequences of that for evolution.

A secondary theme of Singh’s talk will be “the paradox of sex” and why so many species are using such an inefficient form of reproduction.

“Sex is a strange thing,” Singh said. “It’s costly. Individuals that can reproduce asexually produce twice as many offspring as sexually reproducing individuals because they’re not wasting energy on producing males. In spite of that cost, sex is pervasive.”

Singh says there are many theories that have been developed to explain the evolution of sexual reproduction and the maintenance of sexual reproduction. One of the most widely discussed is the Red Queen hypothesis, which is named for a quote from Lewis Carroll’s “Through the Looking Glass.”

“The Red Queen says to Alice ‘Now, here, you see, it takes all the running you can do, to keep in the same place,’” Singh said. “The idea here is that when species are co-evolving with pathogens or parasites, sexually reproducing organisms have an advantage over asexually reproducing ones because they can make their offspring genetically diverse.”

Diversifying enables some offspring to potentially escape infection, at least until the pathogen evolves to infect the novel genotypes. This cycle repeats and repeats, leading to an evolutionary arms race, all the while never really going anywhere at all.  

Singh’s research addresses some fascinating and important questions in evolutionary genetics, such as the question ofhow something so fundamental and important as recombination can vary so much. But, she says, her true mission as a researcher has as much to do with its impact on the students and staff in her lab as it does with the science.

“I can train individuals in science and help them create knowledge,” Singh said. “Help them build confidence. Help them build understanding. Help them find their voice. Help them educate others. The impact of my work is the people I reach. That is why I’m here. To educate and to empower.”

To learn more about upcoming Quack Chats, see the Quack Chats section on Around the O. A general description of Quack Chats and a calendar of additional Quack Chats and associated public events also can be found on the UO’s Quack Chats website.

By Lewis Taylor, University Communications