Science, technology, engineering and mathematics (STEM) fields are traditionally heavily dominated by males, which is of great concern to universities as they try to improve student retention and achievement. One exception to that trend is in the field of biology. Of undergraduate biology majors, more than 60 percent are female and about half of biosciences graduate students are women.
Given that, a common assumption is that biology is one STEM field that no longer faces gender inequalities. However, researchers with Arizona State University and University of Washington have proven otherwise. In the largest analysis of gender differences known of in introductory college-level biology courses, researchers have found evidence of gender-based gaps in both achievement and class participation.
The findings appear in the current issue of Cell Biology Education — Life Sciences Education. The American Society for Cell Biology publishes the quarterly journal.
“Often, gender differences are assumed to be present only in fields where males outnumber females and where there is a strong emphasis on math,” said Sara Brownell, assistant professor with ASU’s School of Life Sciences. “But we are seeing it in undergraduate biology classrooms that do not focus on math — where females make up about 60 percent of the class — indicating that this could potentially be a much more systemic problem. It’s likely this is not unique to physics or biology, but rather true of most undergraduate classrooms.”
Researchers studied 23 classes at a research one (R1) university over a two-year period. The courses included mostly sophomores and biology majors, and were generally taught by two instructors each. Of more than 5,000 students enrolled in the courses, nearly 60 percent were female.
After studying exam performance and class participation, scientists discovered that even with similar college GPAs, female students had average exam scores of 2.8 percent lower than male students. In addition, while female and male students were equally likely to ask a question during class, when asked to volunteer responses to questions, 63 percent of males on average spoke up — even though they comprised only 40 percent of the classroom.
Co-author Sarah Eddy, a postdoctoral scholar at the University of Washington, says the gender gap in the classroom, along with performance equality, present problems.
“Introductory biology classes are the first opportunities for many students to interact with professionals and peers in their intended fields,” said Eddy. “This is a critical opportunity to build up their confidence so that they can succeed in the field. Part of building that confidence is gaining recognition from their classmates and instructors. If females aren’t heard as often as males, they don’t have the same opportunity to succeed as biology majors.”
Brownell and her team suggest that in order to improve student retention and achievement in biology, new strategies must be put into place.
What can instructors do to level the playing field? To positively affect the participation differences in large classes, the researchers recommend using a pre-sorted list of student names to randomly call on them, rather than allowing students to raise their hands. Brownell and her team say that while students may be resistant to the method at first, it is a more equitable way to structure classroom discussions.
“In order to solve the problem, instructors must be aware that it even exists,” shared Brownell. “That’s really the point of this paper — to illustrate that there are gender differences that should not exist. The next steps are to try to determine what causes these differences and then develop additional strategies that instructors can use to lessen those differences.”
Thanks to Arizona State University for contributing this story.
Let’s face it, there are many scientists who are brilliant at the bench but tongue tied at the presenter’s podium. Unfortunately, while graduate school may adequately prepare students for a life of research, not enough emphasis is placed on improving communication skills which can be used to explain complicated research projects to the lay public. That is why it is refreshing to learn that schools such as the California Institute for Regenerative Medicine have created competitions with the express goal of improving scientific communication.
To learn about other fantastic efforts aimed at improving scientific communication, read Science Speak which was published in the Scientists earlier this month.
Regardless of their stage or type, cancers appear to share a telltale signature of widespread changes to the so-called epigenome, according to a team of researchers. In a study published online in Genome Medicine on Aug. 26, the investigators say they have found widespread and distinctive changes in a broad variety of cancers to chemical marks known as methyl groups attached to DNA, which help govern whether genes are turned “on” or “off,” and ultimately how the cell behaves. Such reversible chemical marks on DNA are known as epigenetic, and together they make up the epigenome.
“Regardless of the type of solid tumor, the pattern of methylation is much different on the genomes of cancerous cells than in healthy cells,” says Andrew Feinberg, M.D., M.P.H., a professor of medicine, molecular biology and genetics, oncology, and biostatistics at the Johns Hopkins University School of Medicine. Feinberg led the new study along with Rafael Irizarry, Ph.D., a professor of biostatics at Harvard University and the Dana-Farber Cancer Institute. “These changes happen very early in tumor formation, and we think they enable tumor cells to adapt to changes in their environment and thrive by quickly turning their genes on or off,” Feinberg says.
Feinberg, along with Johns Hopkins University School of Medicine oncology professor Bert Vogelstein, M.D., first identified abnormal methylation in some cancers in 1983. Since then, Feinberg’s and other research groups have found other cancer-associated changes in epigenetic marks. But only recently, says Feinberg, did researchers gain the tools needed to find out just how widespread these changes are.
For their study, the research team took DNA samples from breast, colon, lung, thyroid and pancreas tumors, and from healthy tissue, and analyzed methylation patterns on the DNA. “All of the tumors had big blocks of DNA where the methylation was randomized in cancer, leading to loss of methylation over big chunks and gain of methylation in smaller regions,” says Winston Timp, Ph.D., an assistant professor of biomedical engineering at Johns Hopkins. “The changes arise early in cancer development, suggesting that they could conspire with genetic mutations to aid cancer development,” he says.
The overall effect, Feinberg says, appears to be that cancers can easily turn genes “on” or “off” as needed. For example, they often switch off genes that cause dangerous cells to self-destruct while switching on genes that are normally only used very early in development and that enable cancers to spread and invade healthy tissue. “They have a toolbox that their healthy neighbors lack, and that gives them a competitive advantage,” Feinberg says.
“These insights into the cancer epigenome could provide a foundation for development of early screening or preventive treatment for cancer,” Timp says, suggesting that the distinctive methylation “fingerprint” could potentially be used to tell early-stage cancers apart from other, harmless growths. Even better, he says, would be to find a way to prevent the transition to a cancerous fingerprint from happening at all.
Thanks to Johns Hopkins Medicine for contributing this story.