Urban Evolution Map
Illustration: Casey Chin01__EVOLVING IN A CITY NEAR YOU__: Scores of evolutionary biologists are now investigating how city-dwelling creatures have adapted to life among buildings, traffic, and discarded Big Macs. These are some of the most intriguing urban evolution studies to have emerged in recent years. —B.I.K.
Illustration: Casey Chin02**WESTERN FENCE LIZARD** (*Sceloporus occidentalis*): **Los Angeles, California** - Lizards in the most intensely developed parts of Los Angeles have fewer dorsal scales than their rural counterparts. The adaptation is believed to help them cope with the “urban heat island effect,” which makes cities several degrees hotter than their surroundings.
Illustration: Casey Chin03**WESTERN BLACK WIDOW** (*Latrodectus hesperus*): **Phoenix, Arizona** - Urban spiders produce smaller eggs but in far greater numbers than country spiders. The adaptation, possibly linked to genetic changes in the ovaries, seems designed to maximize reproduction in a high-mortality environment.
Illustration: Casey Chin04**ACORN ANT** (*Temnothorax curvispinosus*): **Cleveland, Ohio** - City ants possess a unique ability to thrive in high temperatures, perhaps due to genetic changes that facilitate the manufacture of stress-managing proteins triggered by heat.
Illustration: Casey Chin05**COYOTE** (*Canis latrans*): **Denver, Colorado** - Coyotes in the city are unusually bold and prone to exploratory behavior. Genes for boldness may have been selected over time, because these coyotes need to draw close to humans to obtain food.
Illustration: Casey Chin06**WATER FLEA** (*Daphnia magna*): **Brussels, Belgium** - Water fleas in urban ponds mature at a much faster rate than their peers in rural ponds. This allows them to produce offspring at a younger age and thus perpetuate their populations in high-stress cities where the mortality rate is high.
Illustration: Casey Chin07**ERMIN MOTH** (*Yponomeuta cagnagella*): **Basel, Switzerland** - Moths in urban settings have lost much of their species' genetic attraction to light. This means fewer urban moths perish by flying into hot light fixtures.
Illustration: Casey Chin08**CREEK CHUB** (*Semotilus atromaculatus*): **Raleigh, North Carolina** - Sparse vegetation surrounding urban waterways allows runoff to pour in at a furious rate; creek chubs in Raleigh have evolved body shapes that can help them withstand these faster currents.
Illustration: Casey Chin09**NORTHERN HOUSE MOSQUITO** (*Culex pipiens*): **London, England** - Mosquitoes that reside in the London Underground do not hibernate and can breed in confined spaces, unlike the aboveground members of their species. Some biologists believe the “London Underground mosquito” is actually a distinct species, since it has trouble breeding with other populations.
Illustration: Casey Chin10**FERAL PIGEON** (*Columba livia*): **Paris, France** - Dark feathers are the rule among pigeons in cities, likely because melanin is effective at sequestering toxic metals that abound in urban environments—especially zinc and possibly lead.
Illustration: Casey Chin11**FERAL PIGEON** (*Columba livia*): **New York, New York** - Pigeons in New York City seem to have the ability to tolerate high-sugar diets without developing hyperglycemia.
Illustration: Casey Chin12**GROVE SNAIL** (*Cepaea nemoralis*): **Leiden, the Netherlands** - Urban snails tend to have yellow shells with dark underbands, as opposed to the pink shells that predominate in the countryside. The adaptation is thought to aid in thermal regulation. Data on shell color was gathered by 1,200 citizen scientists who downloaded the SnailSnap app.
Illustration: Casey Chin13**CRESTED ANOLE** (*Anolis cristatellus*): **San Juan, Puerto Rico** - In cities, these lizards have longer limbs and larger toe pads than ones from Puerto Rico's rain forest. The adaptation makes them faster on flat surfaces and thus more apt to escape predators in environments where there is no foliage to provide cover.
Illustration: Casey Chin14**BLACK SWAN** (*Cygnus atratus*): **Melbourne, Australia** - Black swans in cities are less likely to flee when humans approach, as happens constantly in crowded urban environments. This adaptation appears to be linked to changes in a dopamine receptor gene called DRD4.
Illustration: Casey Chin15**ATLANTIC KILLIFISH** (*Fundulus heteroclitus*): **Newark, New Jersey** - Killifish in Newark Bay have rapidly evolved resistance to the toxic compound dioxin, which kills most other members of the species. The resistance is ascribed to genetic changes that “mute” dioxin's ability to overwhelm a vulnerable signaling pathway.
Snake Bros Keep Getting Bitten by Their Lethal Pets. Only Zoos Can Save Them
Your venomous serpent bites you, and the clock is ticking. America’s zookeepers—and a cooler full of rare antivenom—are your best chance of survival.
Claire McNear
A Billionaire-Backed Startup Wants to Grow 'Organ Sacks' to Replace Animal Testing
R3 Bio has a bold idea for replacing lab animals: genetically-engineered whole organ systems that lack a brain. The long-term goal, says a cofounder, is to make human versions.
Emily Mullin
One Way or Another, Most of Our Electricity Comes From Solar Power
That’s good news, since the forecast is sunshine for the next 5 billion years.
Rhett Allain
A New Implant Aims to Rewire the Brain to Help Stroke Patients
Epia Neuro’s brain-computer interface will include a motorized glove to help stroke patients recover movement in their hand.
Emily Mullin
A New Study Details How Cats Almost Always Land on Their Feet
The secret to this acrobatic skill lies in an extremely flexible part of the spine that allows cats to twist in the air and land safely.
Marta Musso
5 Mysteries That the Artemis Missions to the Moon Could Finally Solve
The moon is not just a barren rock orbiting the Earth. The Artemis missions could answer the great unknowns that the satellite holds.
Jorge Garay
Artemis II: Everything We Know as Its Crew Approaches the Far Side of the Moon
Artemis II remains on course for its lunar flyby as the crew shares historic photos of Earth, tests key systems for future lunar missions, and attempts to fix the toilet.
Javier Carbajal
Artemis II Mission Launches Successfully
The crew of Artemis II will not descend to the moon, but their capsule will fly over the far side of its surface.
Jorge Garay
Your Vape Wants to Know How Old You Are
Companies hope that biometric age-verification tech in cartridges could put flavored vapes back in business. But it's unlikely to solve the real problems.
Boone Ashworth
Artemis II Astronauts Witnessed 6 Meteorites Colliding With the Moon
The moon gets hit by space debris all the time, but some of it is so large that the impact generates light that can be seen thousands of kilometers away.
Jorge Garay
No One Knows Where US Vaccine Policy Goes Next
Robert F. Kennedy Jr.’s sweeping changes to federal vaccine guidance are paused for now. But even if they’re reversed, lasting damage has already been done.
Emily Mullin
Even Artemis II Astronauts Have Microsoft Outlook Problems
The mission commander’s email inbox failed during the journey to the moon. Have they tried turning the computer off and back on again?
Jeremy White