The brightest take on this week’s science
Welcome back to Spark!
This week, we are exploring the first evolutionary evidence of humans adapting to poison.
Plus, new evidence just dropped on what happens to sperm in space… and it doesn’t look great.
Also in this issue:
🥗 A unique diet that could slow aging
🤯 A tiny monkey that can fit on your finger
🔬 A smiling microscope mystery
Scroll to learn more!
LOOK IN
Humans in the Andes Evolved a Rare Ability
(Edsel Querini/iStock/Getty Images)
Communities living in the Andes of South America have evolved a strange ability to tolerate poison.
Arsenic is a toxic metalloid that can be lethal when it reaches certain concentrations in drinking water. But not for everyone.
For many millennia, volcanic bedrock in the Andes has disintegrated and seeped into the region’s groundwater, contaminating the natural source with a dangerous concentration of arsenic.
Yet people in the region continued to drink it.
According to DNA analysis, northern populations in Argentina carry a unique gene variant, which helps them metabolize arsenic more safely.
It’s the first evidence of our species adapting to a toxic chemical.
HEADLINES
This Week in Science
LOOK OUT
Microgravity Can Disorient Human Sperm
(Burazin/The Image Bank/Getty Images)
The future of space travel has a sex problem. A trip beyond our planet may very well disorient human sperm, making it harder for them to find an egg.
In the lab, scientists at the University of Adelaide in Australia have simulated microgravity conditions to see how the sperm of humans, pigs, and rodents cope.
Without the sure pull of gravity as a guide, the sperm seem to become disoriented.
As a result, the cells were less able to navigate a channel designed to mimic the female reproductive tract.
Plus, in mice, there seems to be another danger. Rodent sperm subjected to microgravity are less able to successfully fertilize an egg.
Perhaps the same occurs with human sperm…
ZOOM ZONE
Microscope Mystery: What Do You See?
(David Gregory & Debbie Marshall/Wellcome Collection/CC BY 4.0)
A) Cell mitosis
B) Dinoflagellates
C) Inner ear bone
D) Giardia
Answer at the bottom.
LOW-KEY GENIUS
Unique Diet Could Slow Your Brain Aging
(Jolygon/iStock/Getty Images Plus)
You’ve probably heard about the potential powers of the Mediterranean diet, but there’s a customized version that may be even healthier.
It’s called the MIND diet, and it’s essentially a combination of the Mediterranean diet and the DASH diet, or the Dietary Approaches to Stop Hypertension, plus a few more tweaks.
The DASH diet is specifically focused on fruit, vegetables, wholegrains, and low-fat dairy to lower blood pressure. But it may also do much more.
In a new study, the MIND diet's effects on brain aging were impressive.
Participants who stuck most closely to the MIND diet did not lose as much gray matter tissue as their age-matched peers.
These brain changes were equivalent to 2.5 years of slower aging across the study period.
WOW FACTOR
Science Fact of The Week
(Floridapfe from S.Korea Kim in cherl/Moment/Getty Images)
This photo isn’t AI-generated. That adorable creature really does exist here on Earth.
It’s called a pygmy marmoset: the smallest monkey in the world.
A native primate of the Amazon rainforest, it is so very tiny that, as an infant, it could cling to your index finger with its entire length.
DOPAMINE HIT
Before You Go…
Until next time!
(Gif by xponentialdesign on Giphy)
Microscope answer: Giardia
This tiny pathogen causes Giardia infections. Giardia lamblia colonizes the gut and triggers a whole host of nasty gastrointestinal issues. When stained, the organism looks like it has a smiley face on it. 😀
That’s all for today… see you next week!
- Carly
