Professor Sean Jordan pictured with rocks that are about 3.5 billion years old from the Strelley Pool Formation in Western Australia. The rocks on the table are a mixture of those and some other samples around 2.5 billion years old, also from Western Australia.

How did life begin? Dr Seán Jordan wants to know

29/11/2023

The question of when and how life arose are some of the key research questions for Dr Seán Jordan, a newly appointed staff member in the School of Chemical Sciences. This research involves looking at fossils that are several billion years old, as well as artificially generating structures in the lab that look like they may have been produced by life.

Dr Jordan, who is from Rush county Dublin - as is his wife - and is father to an 11-week-old boy, was always interested in science and nature and how the world worked. He applied for DCU, through the Chemical Sciences General Entry programme, and by his second year, he had decided to work in Environmental Science, and did his final year project with Dr Brian Kelleher.

After he finished his undergraduate degree he went to Australia, where he took a year out before returning to do a PhD with Dr Kelleher working on marine sediments, and he began to find the past more fascinating than the present. “I was more interested in looking back at the past and understanding how climate has changed over time,” said Dr Jordan.

Early career

After his PhD, he saw an advertisement for a post-doc position in University of London (UCL) that was focused on finding the origin of life, and recreating the conditions for early life in the laboratory. He applied, and was accepted into the lab of Professor Nick Lane, who, as well as being a renowned scientist, had been the author of several popular science books. “I learned a lot about how to write, not just scientific papers, but general interest articles as well,” said Dr Jordan.

At UCL, he sought to understand what the first cell membranes would have been like. “All life is cellular so the first life had to be cellular as well,” said Dr Jordan. “It just makes sense.”

This work suited him as he had a good understanding of membrane chemistry and the molecules involved. From this he produced research papers and started to generate his own ideas.

He did a huge amount of microscopy, generating lots of images of the artificial cells that were being made in the UCL lab. Then he noticed something. Under the microscope the synthetic structures were very similar to reported early microfossils. They were the same size, shape and morphology.

“I started to think that it was possible that we were looking at non-living structures and mistaking them for signs of life,” said Dr Jordan.

Dr Jordan wrote up a "la Caixa" Foundation Postdoctoral Junior Leader Fellowship (Marie Sklodowska-Curie COFUND) proposal to look into this in collaboration with some palaeontologists. He spent a year working at the laboratory of Professor Zia Martins, an Astrobiology and Cosmochemistry professor based in Lisbon. This was rewarding, but then a lecturing position in Sligo for the Atlantic Technological University came up and he decided to take it.

“The life of a post-doc is insecure so I decided to take the secure job. My wife and I knew that we wanted to come back to Ireland eventually, so it was a stepping stone back.”

ERC grant

He began to write grant proposals for Science Foundation Ireland (SFI) and the European Research Council (ERC). He applied for an SFI-IRC Pathway grant and got it, and was then offered a job at DCU, which he took. After a lot of hard work, he was also awarded a prestigious ERC Starting Grant.

Commenting on the ERC award, Professor John Doyle, Vice President of Research said: "Securing grants such as these is a key outcome identified in the research element of the University's latest strategic plan."

"It reflects the ambition set out in the plan and highlights the direction in which we must continue to travel. It also has a practical impact on targeted increases in research outputs and PhD numbers. We look forward to seeing the work Dr Jordan and his team produce over the next five years."

Dr Jordan saw the ERC award as a natural progression from his Marie Sklodowska-Curie project, but much larger in scale, and focused on generating big data and using a machine learning approach. “The ERC funds high risk, high reward - basic science,” said Dr Jordan.

“What I’ll be doing is continuing to develop cell membranes from their earliest basic aspects, but then looking at how those might be fossilised. We’ll take the cell membranes that we made and we will artificially fossilise them - basically trap them in silica and then we are going to cook them in a high temperature, high pressure autoclave. That replicates what happens over geological time as best as possible.”

Dr Jordan will be applying the same techniques to two sets of microfossils that scientists believe were generated by life in the early Earth. These are 3.5 billion year old fossils from western Australia believed to contain some of the oldest traces of life on Earth, and another set of microfossils, about 800 million years old, from Svalbard in Norway, which scientists are confident emerged from life.

The Svalbard microfossils are from a time when scientists know that life existed on Earth and they have been well studied and derive from multiple different species. “We know these are fossils of living organisms so the results from them can be compared to the non-living structures we make in the lab and the early fossils from Australia that we’re not sure about,” said Dr Jordan.

The idea is to subject the artificial structures and the two sets of fossils to the same kind of analysis, and to see whether a definite answer can be found as to whether they are produced by life, or produced by inorganic processes. He also wants to develop a standardised method of analysing fossils’ biogenecity.

Mars

In the context of the upcoming missions to Mars, and the plan to bring samples of rock back to Earth it will be crucial to have a standardised, internationally agreed, well tested method for analysing whether ancient micro structures were produced by life forms or not.

"This will all be very important when they start bringing back samples from Mars,” said Dr Jordan. “The reality is that we have loads of samples from the early Earth today, but there is no agreement on which ones were truly living and which weren’t. It will be about 10 years before samples are returned to Earth from Mars. At that stage, we need to be as confident as possible that we can apply techniques that everyone agrees with.”

The samples that will be brought back from Mars might not contain signs of life, said Dr Jordan, but, instead, contain signs of life’s emergence, a proto-bio signature. “To me, this is just as exciting as looking at the fossilised remains of actual life,” said Dr Jordan. “Once life starts it probably won’t take too long for it to spread somewhere else on the same planet.”

Dr Jordan is in the process of recruiting for his lab, and when up and running he will have four PhD students and two post-docs. He will be based in the Nano Research Facility (NRF) where he will be able to keep a very modern lab space free of organic material.

As for the big question of whether he thinks scientists will find life beyond Earth, he says: “From studying the origin of life, my gut feeling is that microbial life is very common and we will probably see it in our Solar System eventually.”