Skip to main content
Premium Trial:

Request an Annual Quote

Nettie Stevens's Doodle

The Google Doodle today features Nettie Stevens for what would've been her 155th birthday. As Vox writes, Stevens uncovered the connection between the Y chromosome and maleness by studying mealworms. "Thanks to Stevens's work — and the work that built upon it — we now know that sex is hereditary, and that dads' sperm in particular determine the sex of offspring," it adds.

Stevens was born in Vermont in 1861, but Vox notes that she was a latecomer to science, enrolling at Stanford University at age 35 where she earned a bachelor's and a master's degree. She then sought a doctorate at Bryn Mawr College where she tackled the genetics of sex determination. By examining chromosomes from mealworms under the microscope, Stevens found that both male and female mealworms had 20 chromosomes, but one of the chromosomes in the male worms was smaller than the others. "This seems to be a clear case of sex determination," Stevens wrote in her Studies in Spermatogenesis report.

But, Vox adds, Stevens rarely gets the credit for linking chromosomes to sex determination; that instead goes to E. B. Wilson, who was working on the same question in a different species. He found that males of that species harbored one fewer chromosomes than females, but he also thought there were environmental influences at play, Vox says. It adds that Wilson likely gets credited for this over Stevens, even though she made the stronger argument, because he was a higher-profile researcher and male.

According to the Independent, Nobel Prize-winner Thomas Morgan, who also studied chromosomes, once wrote that Stevens's "single-mindedness and devotion, combined with keen powers of observation; her thoughtfulness and patience, united to a well-balanced judgment, accounts, in part, for her remarkable accomplishment."

Stevens died in 1912 of breast cancer.

Filed under

The Scan

Foxtail Millet Pangenome, Graph-Based Reference Genome

Researchers in Nature Genetics described their generation of a foxtail millet pangenome, which they say can help in crop trait improvement.

Protein Length Distribution Consistent Across Species

An analysis in Genome Biology compares the lengths of proteins across more than 2,300 species, finding similar distributions.

Novel Genetic Loci Linked to Insulin Resistance in New Study

A team reports in Nature Genetics that it used glucose challenge test data to home in on candidate genes involved in in GLUT4 expression or trafficking.

RNA Editing in Octopuses Seems to Help Acclimation to Shifts in Water Temperature

A paper in Cell reports that octopuses use RNA editing to help them adjust to different water temperatures.