Week in Review: July 29–August 2

The violence of climate change; the value of ethnic diversity in science; a sampling of newly sequenced genomes; be wary of the classic correlation-causation trap

Jef Akst
Jef Akst

Jef Akst is managing editor of The Scientist, where she started as an intern in 2009 after receiving a master’s degree from Indiana University in April 2009 studying the mating behavior of seahorses.

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Aug 2, 2013

Climate increases breed violence

WIKIMEDIA, DAVID MONNIAUXA meta-analysis of more than 12,000 years of world history and climate data, collected by nearly 190 researchers in diverse disciplines, provides some of the strongest evidence yet that human violence does increase with warming temperatures and precipitation extremes. Specifically, interpersonal violence, such as domestic violence or rape, is expected to rise by 4 percent for every standard deviation of change, while the frequency of intergroup conflict could rise by 14 percent. By 2050, global temperatures are expected to increase by at least two standard deviations. “The paper is remarkably strong,” Thomas Homer-Dixon, an environmental and political scientist at the University of Waterloo in Ontario, told The Scientist. “[It means] the world will be a very violent place by mid-century if climate change continues as projected.”

There remains, however, the question of why. Coauthor Solomon Hsiang from the University of California, Berkeley,...

Don’t underestimate the power of diversity

WIKIMEDIAEthnic diversity is one key to scientific progress, argues W. Malcolm Byrnes of Howard University College of Medicine in Washington, DC, in an opinion piece at www.the-scientist.com. Byrnes highlights the life of Ernest Everett Just, an early 20th century African American biologist credited with discovering what is known as the fast block to polyspermy, as an example of how diversity can bring different experiences and perspectives to the table. Just emphasized the importance of the cytoplasm in cellular differentiation, whereas other big hitters of the time, such as Thomas Hunt Morgan, argued that genes were the dominant driver of cellular processes. And although Morgan’s camp was right in many ways, as the ENCODE project recently revealed, gene activity is highly dependent on extranuclear determinants. Brynes argues that Just’s ability to hold his cytoplasmic view in the face of such strong opposition was due, in part, to his cultural background.

“As a professor at Howard University, Just was familiar with the landscape of black intellectual thought,” Brynes writes. “He knew about the writings of scholars such as W.E.B. Du Bois and Alain Locke. Du Bois, for example, believed that race was not biologically determined, but was derived from the history and shared experience of a group. On the other hand, Locke believed that the free exchange of cultural ideas between ethnic groups was vital to the success of a nation, and he advocated for cultural reciprocity. Did these ideas influence Just’s view of the cell? We cannot know for sure without historical evidence, but the thought is intriguing.”

Palm oil, asexual rotifers, and a tunicate

MALAYSIAN PALM OIL BOARDIn this latest edition of The Scientist’s Genome Digest, we highlight several newly sequenced species and describe what researchers are learning from their DNA. The genome of the African oil palm (Elaeis guineensis), for example, which yields a commonly used edible oil, revealed mutations in the SHELL gene that are responsible for the different amounts of oil production observed in the plant’s three varieties. In the animal kingdom, the genome of a bdelloid rotifer species, Adineta vaga, solidifies the view that the species is asexual by revealing a genome that is incompatible with meiosis, the cellular division process that yields gametes. And the genome of the golden star tunicate (Botryllus schlosseri), the closest invertebrate relative of vertebrates, contains homologs of vertebrate genes for cardiac function, sight, hearing, and the formation of the cellular components of blood even though the animal lacks eyes and ears and has only a primitive circulatory system. Read more about these and other genomes in this week’s Genome Digest.

Don’t forget: Correlation does not mean causation

WIKIMEDIA, SAM DAOUDIt may not be enough to have taken a few statistics courses; according to Vladica Velickovic of the University of Niš in the Republic of Serbia, scientists are still making some classic statistical mistakes. Specifically, when it comes to correlational analysis, which measures the relationship between two variables, researchers often succumb to three common misconceptions, which can lead to some “erroneous conclusions about the true nature of the relationship between the studied phenomena,” he writes in an opinion piece for The Scientist.

First, Velickovic points to a few examples of false causal relationships where only a correlation had been found. In addition, he says, researchers sometimes draw conclusions about individual relationships based on group data, another statistical no-no, and a correlation of zero does not imply independence, as some scientists incorrectly assume.

More news in life science:

Famed Indian Biologist Dies

Obaid Siddiqi, regarded as one of the founders of modern biology in India, has passed away at age 81.

Neurologist Charged with Murder

A neurologist at the University of Pittsburgh is accused of using cyanide to kill his wife, a fellow neurologist at the same institution.

The Roots of Monogamy

A new analysis suggests that infanticide drove the evolution of pair living in some primate species, though another study reaches a different conclusion.

Inca Children Got High Before Death

Evidence from mummified remains of three children discovered atop an Argentinian volcano suggests they were drunk and stoned for a year leading up to their ritual sacrifice.

Pharma Moves Toward Transparency

The pharmaceutical industry has agreed to share data from clinical trials with researchers, patients, and the public.

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