
Youcef Sellam in his lab with the fossil filaments discovered within the gypsum.
Youcef Sellam
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Youcef Sellam
In a approach, it began with a highway journey a couple of decade in the past.
“My father, he had the automotive so I needed to borrow the automotive from him,” says Youcef Sellam, who was interning on the College of Modena e Reggio Emilia in Italy on the time. “Yeah, let’s go collectively,” his dad mentioned.
The daddy-son duo had been headed north to a gypsum quarry close to the Mediterranean coast of their residence nation of Algeria.
Sellam and his colleagues would go on to seek out microbial fossils in these minerals, a primary for Algerian gypsum. And later, as a Ph.D. pupil on the College of Bern, he and a crew of scientists would present they may use a particular instrument to detect the chemical signatures of these microbes — with the concept they may someday use the method to scan for historic life amongst related minerals on Mars.
The outcomes had been revealed within the journal Frontiers in Astronomy and Space Sciences.
“What this research in Algeria actually does is it highlights that you need to use chemical strategies to deduce that biology is within the mineral,” says biochemist Bonnie Baxter, who directs the Nice Salt Lake Institute at Westminster College and wasn’t concerned within the analysis. “And chemical strategies are just a bit extra transferable to Mars.”

Tthe Sidi Boutbal quarry, situated within the Oran district, Algeria
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A hefty haul containing the tiniest of passengers
Sellam’s dad, a statistician, ignited in him a curiosity in regards to the world.
“With the Algerian forex, it is fairly costly,” he says, “however the first science journal I bought, it was from my father. The primary biology guide, it was from my father. And I used to be tremendous thirsty to be taught on a regular basis.”
Sellam went on to review microbiology and paleontology. He turned taken with historic microbes and the tiny fossils they depart behind in minerals like gypsum. After which, throughout that internship in Italy in 2016, he was chatting along with his supervisor when the celebs aligned.
“He mentioned, ‘Yeah, we all know virtually every part in regards to the Mediterranean,'” remembers Sellam, “‘however there’s a place that we could not go and we want to get some gypsum.'”
That place occurred to be Algeria, which is how Sellam wound up driving his father’s inexperienced Toyota Echo to that quarry. Over a pair days, he used a hammer and chisel to gather greater than 60 kilos of gypsum.
“I used to be the one making the sampling whereas my dad was simply watching!” he chuckles.
As soon as Sellam bought the samples to the lab, he noticed sinuous filaments preserved within the mineral. These had been historic, fossilized microbes, “which is a sign that gypsum might protect life,” says Sellam. “As a result of they’re fossils, we can’t be 100% certain in regards to the species.” They may have been a type of algae or micro organism.
After that internship and incomes three Grasp’s levels, Sellam bought a pair odd jobs. However when COVID hit, he was out of labor for a number of years.
“I used to be going via a tough time as a result of I could not show to my father that I used to be doing one thing attention-grabbing,” says Sellam. “So it was type of disappointment.”
However Sellam utilized to universities and for scholarships — and finally, he bought into the Ph.D. program in physics on the College of Bern in Switzerland. And that basically impressed his dad. “He was like, ‘OK, now we’re speaking,'” remembers Sellam.

Youcef Sellam and his father, Hamed.
Youcef Sallam
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Youcef Sallam
“Preserve going”
In graduate college, he labored on an concept to assist fill within the fossil file of life on Earth by Mars.
That is as a result of it is solely attainable to look again at microbial life on Earth to this point. Plate tectonics and volcanic exercise on our planet when it was only a child erased the clues of its early existence.
“So mainly, we misplaced the primary billion years relating to the historical past of the Earth,” says Sellam, “We’ve a spot.” That hole contains any actually historic microbes which may have in any other case been fossilized.
Fortunately, although, there’s Mars. “Mars is a screenshot of the early Earth,” Sellam says. “Principally, what Mars seems like proper now’s what was the Earth trying like 4 billion years in the past. After all, not precisely, however fairly related.”
By finding out Mars, scientists would possibly be taught in regards to the historic Earth. And if — and it is a huge if — Mars has microbes fossilized in its gypsum, researchers will want the appropriate instruments to load onto rovers to search for that life.
Sellam’s Ph.D. targeted on testing whether or not a small however highly effective instrument known as a laser ablation ionization mass spectrometer (LIMS) might detect the chemical traces of these microbes.
“It is mainly a laser beam hitting the pattern,” explains Sellam. “And this laser will vaporize a part of the fabric, creating some atoms. You should have a spectra of the totally different parts which can be present within the rock.”
Taking a look at these spectra can decide whether or not there’s fossilized life within the rock. However earlier than that laser could possibly be despatched to Mars, it needed to be examined on Earth, and Sellam had the right pattern — his Algerian gypsum.
It labored fantastically. “We proved that our instrument is succesful to detect signatures of life within the gypsum,” says Sellam, suggesting that someday it’d assist do the identical on Mars.
Baxter says the research highlights the particular relationship between minerals and microbes. “It appears that evidently this sort of intimate interconnection has been current for billions of years on our planet and probably elsewhere,” she says. “I feel it is a stupendous signature of how our biosphere and our Earth are working collectively to create what we see on this planet.”
Nonetheless, Baxter believes the laser method on Mars may be tough as a result of it must detect fossils which can be billions — as an alternative of tens of millions — of years outdated. “So I feel that is an enormous caveat,” she says. And he or she’s curious to know extra in regards to the biology of the microbes fossilized within the Algerian gypsum.
As for Sellam, he is proud that his first ever scientific publication highlights his residence nation. However simply earlier than he completed it up, in September, his father handed away.
However, he says, “in actuality, he all the time standing with me. Possibly he’ll say, ‘Do not cease right here. Preserve going.'”