May 2022, Issue 1 Table of Contents

Feature

Composite image of earliest humans and wooly mammoths
New Evidence Complicates the Story of the Peopling of the Americas
Emma Yasinski | May 2, 2022
New techniques have shown that people reached the New World far earlier than the long-standing estimate of 13,000 years ago, but scientists still debate exactly when humans arrived on the continent—and how.

Speaking of Science

Crossword article image
Ten Minute Sabbatical
Ten Minute Sabbatical
Take a break from the bench to puzzle and peruse

Critic at Large

Notebook

Photo of fish in the Haemulidae family
Fish Are Chattier Than Previously Thought
Fish Are Chattier Than Previously Thought
Once thought to be silent, fish turn out to produce a range of vocalizations—so polluting the oceans with noise could pose a danger to them.
Image of sperm hooks (<em>Peromyscus maniculatus</em>)
The Mystery of the Mouse Sperm Hook
The Mystery of the Mouse Sperm Hook
Nearly all mouse sperm have hooks on their heads. But new research suggests the structures slow them down—so what exactly is their purpose?

Infographics

Illustrated map showing where evidence was found of the earliest humans
Infographic: Mixed Evidence on Human Occupation of the Americas
Infographic: Mixed Evidence on Human Occupation of the Americas
Diverse lines of evidence point to humans’ presence in the New World long before the dawn of Clovis culture. But rewriting this chapter of human history raises many questions about how these early people came to inhabit these continents.

The Literature

Image of not-to-scale renderings of the skulls of various primate species
Surface Area of Tooth Roots Predicts Primate Body Size
Surface Area of Tooth Roots Predicts Primate Body Size
Researchers determine that a primate’s tooth root, and not just its crown, can yield reliable information about body size, but the relationship between root surface area and diet isn’t as clear.
Photo of a North American caribou (Rangifer tarandus) in Jasper National Park in Canada
Dozens of Genes Tied to Caribou’s Seasonal Migration
Dozens of Genes Tied to Caribou’s Seasonal Migration
Researchers tracked the movements of endangered caribou and sequenced a portion of their genomes to determine which genes may influence migratory behavior.

Foundations

Photo of John Calhoun crouches within his rodent utopia-turned-dystopia
Universe 25, 1968–1973
Universe 25, 1968–1973
A series of rodent experiments showed that even with abundant food and water, personal space is essential to prevent societal collapse.