Katrin Hammerschmidt
@khammerschmidt.bsky.social
Evolution, Microbiology, Multicellularity, Division of Labour, Major Transitions in Evolution, Life Cycles, Symbiosis
Kiel University
Kiel University
Pinned
Happy to see this out @NatComm
We found that the unicellular coastal cyanobacterium Cyanothece sp uses sodium energetics rather than the typical proton energetics to fix N2. Sodium energetics likely is more widespread and affects the global nitrogen cycle.
Congrats Si Tang
#microsky
t.co/A4lIVcK2V3
We found that the unicellular coastal cyanobacterium Cyanothece sp uses sodium energetics rather than the typical proton energetics to fix N2. Sodium energetics likely is more widespread and affects the global nitrogen cycle.
Congrats Si Tang
#microsky
t.co/A4lIVcK2V3
Reposted by Katrin Hammerschmidt
The 2026 Guarda Summer Course in Evolutionary Biology is now accepting applications. Amazing place, amazing course, amazing opportunity for early grad students.
tb.ethz.ch/education/gu...
tb.ethz.ch/education/gu...
Summer school:<br> Evolutionary Biology in Guarda
Information about the annual summer school Evolutionary Biology in Guarda
tb.ethz.ch
December 10, 2025 at 2:24 PM
The 2026 Guarda Summer Course in Evolutionary Biology is now accepting applications. Amazing place, amazing course, amazing opportunity for early grad students.
tb.ethz.ch/education/gu...
tb.ethz.ch/education/gu...
Reposted by Katrin Hammerschmidt
1/28 New preprint up, which I think is the best theoretical idea I've ever had. We asked a simple question: what are the costs of investment into non-reproductive somatic cells? Turns out these costs decrease with the *logarithm* of organism size!
www.biorxiv.org/content/10.6...
www.biorxiv.org/content/10.6...
The fitness costs of reproductive specialization scale inversely with organismal size
The evolution of reproductive specialization represents a fundamental innovation in multicellular life, yet the conditions favoring its evolution remain poorly understood. Here, we develop a populatio...
www.biorxiv.org
December 9, 2025 at 7:44 PM
1/28 New preprint up, which I think is the best theoretical idea I've ever had. We asked a simple question: what are the costs of investment into non-reproductive somatic cells? Turns out these costs decrease with the *logarithm* of organism size!
www.biorxiv.org/content/10.6...
www.biorxiv.org/content/10.6...
Reposted by Katrin Hammerschmidt
I am very excited to announce that a fully funded PhD position is available in my group.
Topic: Synergistic coevolution in mono-specific and multi-species microbial consortia
Please RT or forward this information to interested candidates.
Deadline: 11.01.26
More info:
shorturl.at/f1TuF
Topic: Synergistic coevolution in mono-specific and multi-species microbial consortia
Please RT or forward this information to interested candidates.
Deadline: 11.01.26
More info:
shorturl.at/f1TuF
November 27, 2025 at 2:24 PM
I am very excited to announce that a fully funded PhD position is available in my group.
Topic: Synergistic coevolution in mono-specific and multi-species microbial consortia
Please RT or forward this information to interested candidates.
Deadline: 11.01.26
More info:
shorturl.at/f1TuF
Topic: Synergistic coevolution in mono-specific and multi-species microbial consortia
Please RT or forward this information to interested candidates.
Deadline: 11.01.26
More info:
shorturl.at/f1TuF
Reposted by Katrin Hammerschmidt
#microsky #mevosky @spp2389.bsky.social
A PhD position is available in my lab to work on:
Emergence and self-organisation of bacterial metabolism in consortia of cross-feeding bacteria.
Please RT
Deadline: 12.11.25
More infos 👇
shorturl.at/rAKAT
A PhD position is available in my lab to work on:
Emergence and self-organisation of bacterial metabolism in consortia of cross-feeding bacteria.
Please RT
Deadline: 12.11.25
More infos 👇
shorturl.at/rAKAT
October 30, 2025 at 7:50 AM
Reposted by Katrin Hammerschmidt
Very proud that @gauravathreya.bsky.social's brilliant work based on his Master's thesis is out as his first paper in @asn-amnat.bsky.social. Interested in host-symbiont interdependence, eukaryogenesis, evolutionary transitions in individuality, and some great theory to back it?...check out the🧵👇
Interested in host-symbiont interdependence, eukaryogenesis, and evolutionary transitions in individuality? my first paper just came out! With @gokhalecs.bsky.social and Pete Czuppon, we study when & how individuality emerges in a host-endosymbiont collective doi.org/10.1086/737588 a short thread🧵:
July 24, 2025 at 6:34 AM
Very proud that @gauravathreya.bsky.social's brilliant work based on his Master's thesis is out as his first paper in @asn-amnat.bsky.social. Interested in host-symbiont interdependence, eukaryogenesis, evolutionary transitions in individuality, and some great theory to back it?...check out the🧵👇
Reposted by Katrin Hammerschmidt
One of the most exciting discoveries from our lab so far is now online as a preprint!
Read a story on how the ParMR and Min systems started to collaborate to create the CorMR cytoskeleton, which now controls cell shape in multicellular cyanobacteria:
www.biorxiv.org/content/10.1...
Read a story on how the ParMR and Min systems started to collaborate to create the CorMR cytoskeleton, which now controls cell shape in multicellular cyanobacteria:
www.biorxiv.org/content/10.1...
Evolutionary repurposing of a DNA segregation machinery into a cytoskeletal system controlling cyanobacterial cell shape
Bacteria, despite their diversity, use conserved cytoskeletal systems for their intracellular organization. In unicellular bacteria, the ParMRC DNA partitioning apparatus is well known for forming act...
www.biorxiv.org
July 2, 2025 at 11:35 AM
One of the most exciting discoveries from our lab so far is now online as a preprint!
Read a story on how the ParMR and Min systems started to collaborate to create the CorMR cytoskeleton, which now controls cell shape in multicellular cyanobacteria:
www.biorxiv.org/content/10.1...
Read a story on how the ParMR and Min systems started to collaborate to create the CorMR cytoskeleton, which now controls cell shape in multicellular cyanobacteria:
www.biorxiv.org/content/10.1...
Reposted by Katrin Hammerschmidt
How does agency change as life evolves from single cells to complex bodies? This review by Stuart Newman and colleagues examines the surprising roles of development, microbes, and even cancer in reshaping what organisms can do. @multicellgenome.bsky.social www.journals.uchicago.edu/doi/pdf/10.1...
June 24, 2025 at 1:15 PM
How does agency change as life evolves from single cells to complex bodies? This review by Stuart Newman and colleagues examines the surprising roles of development, microbes, and even cancer in reshaping what organisms can do. @multicellgenome.bsky.social www.journals.uchicago.edu/doi/pdf/10.1...
Reposted by Katrin Hammerschmidt
1/27 We have a new paper out! Turns out that snowflake yeast have been hiding a secret from us - they've evolved a (very!) crude circulatory system. Not with blood vessels or a heart, but through spontaneous fluid flows powered by their metabolism. 🧪🔬
www.science.org/doi/full/10....
www.science.org/doi/full/10....
June 24, 2025 at 4:52 PM
1/27 We have a new paper out! Turns out that snowflake yeast have been hiding a secret from us - they've evolved a (very!) crude circulatory system. Not with blood vessels or a heart, but through spontaneous fluid flows powered by their metabolism. 🧪🔬
www.science.org/doi/full/10....
www.science.org/doi/full/10....
Reposted by Katrin Hammerschmidt
We loved hearing @khammerschmidt.bsky.social talk about evolution at the #MultiBac2025 conference this January - check out the @asm.org report on the origins of early microbial life!
Happy to have been part of EVOLUTION & MECHANISMS GOVERNING MULTICELLULARITY—one of 3 workshops behind @asm.org’s new report. Big questions, great conversations—looking back on origins of microbial life and what lies ahead. Highly recommended read: asm.org/reports/earl...
#MicroSky #MEvoSky #EvoSky
#MicroSky #MEvoSky #EvoSky
June 24, 2025 at 9:04 AM
We loved hearing @khammerschmidt.bsky.social talk about evolution at the #MultiBac2025 conference this January - check out the @asm.org report on the origins of early microbial life!
Happy to have been part of EVOLUTION & MECHANISMS GOVERNING MULTICELLULARITY—one of 3 workshops behind @asm.org’s new report. Big questions, great conversations—looking back on origins of microbial life and what lies ahead. Highly recommended read: asm.org/reports/earl...
#MicroSky #MEvoSky #EvoSky
#MicroSky #MEvoSky #EvoSky
June 24, 2025 at 7:39 AM
Happy to have been part of EVOLUTION & MECHANISMS GOVERNING MULTICELLULARITY—one of 3 workshops behind @asm.org’s new report. Big questions, great conversations—looking back on origins of microbial life and what lies ahead. Highly recommended read: asm.org/reports/earl...
#MicroSky #MEvoSky #EvoSky
#MicroSky #MEvoSky #EvoSky
Reposted by Katrin Hammerschmidt
New preprint: eukaryotic origins! 🥁
We propose that iron -not oxygen- may have delayed the rise of complex life. Our model reframes the “oxygen delay” puzzle: the gap between atmospheric O2 and early eukaryotic fossils may reflect iron-mediated stress, not for O2:
www.biorxiv.org/content/10.1...
We propose that iron -not oxygen- may have delayed the rise of complex life. Our model reframes the “oxygen delay” puzzle: the gap between atmospheric O2 and early eukaryotic fossils may reflect iron-mediated stress, not for O2:
www.biorxiv.org/content/10.1...
June 2, 2025 at 6:19 PM
New preprint: eukaryotic origins! 🥁
We propose that iron -not oxygen- may have delayed the rise of complex life. Our model reframes the “oxygen delay” puzzle: the gap between atmospheric O2 and early eukaryotic fossils may reflect iron-mediated stress, not for O2:
www.biorxiv.org/content/10.1...
We propose that iron -not oxygen- may have delayed the rise of complex life. Our model reframes the “oxygen delay” puzzle: the gap between atmospheric O2 and early eukaryotic fossils may reflect iron-mediated stress, not for O2:
www.biorxiv.org/content/10.1...
Reposted by Katrin Hammerschmidt
Abstract submission extended to 1 July – Submit your work now!
Learn about the origins and #evolution of #multicellularity at EMBO Workshop "Evolution and origins of multicellularity across the tree of life" in Barcelona, ES, 9–11 Oct
Abstract submission by 1 June
Registration by 20 July
meetings.embo.org/event/25-mul...
#EMBOmulticellularity #EMBOevents 🧪
Abstract submission by 1 June
Registration by 20 July
meetings.embo.org/event/25-mul...
#EMBOmulticellularity #EMBOevents 🧪
Evolution and origins of multicellularity across the tree of life
The study of the origins and evolution of multicellularity in different lineages has recently captured the attention of many research groups and is fueling the generation of numerous innovative resea…
meetings.embo.org
June 3, 2025 at 12:14 PM
Abstract submission extended to 1 July – Submit your work now!
Reposted by Katrin Hammerschmidt
Kimberly Chen, a former postdoc in my lab, has published a new article in Genome Biology and Evolution. Selection on mixed populations of Chlamydomonas resulted in the evolution of multicellular structures, all from 2 of 10 founder strains. www.linkedin.com/in/kimberly-...
doi.org/10.1093/gbe/...
doi.org/10.1093/gbe/...
Genetic Predisposition Toward Multicellularity in Chlamydomonas reinhardtii
Abstract. The evolution from unicellular to multicellular organisms facilitates further phenotypic innovations, notably cellular differentiation. Multiple
doi.org
June 2, 2025 at 10:31 AM
Kimberly Chen, a former postdoc in my lab, has published a new article in Genome Biology and Evolution. Selection on mixed populations of Chlamydomonas resulted in the evolution of multicellular structures, all from 2 of 10 founder strains. www.linkedin.com/in/kimberly-...
doi.org/10.1093/gbe/...
doi.org/10.1093/gbe/...
Reposted by Katrin Hammerschmidt
This is still open for another week or so! Please apply :)
🧩 PhD Position – Origins of Darwinian Inheritance 🧩
This joint PhD project between the @rug.nl (Rampal Etienne & Martijn Egas) and @utrechtuniversity.bsky.social (Bram van Dijk) explores how simple prebiotic systems could evolve reliable information transfer.
Apply here: shorturl.at/WgYMF
This joint PhD project between the @rug.nl (Rampal Etienne & Martijn Egas) and @utrechtuniversity.bsky.social (Bram van Dijk) explores how simple prebiotic systems could evolve reliable information transfer.
Apply here: shorturl.at/WgYMF
June 3, 2025 at 2:51 PM
This is still open for another week or so! Please apply :)
Reposted by Katrin Hammerschmidt
#multicellularity lovers: the website for the EMBO workshop in multicellularity is live. Barcelona is waiting for you! #protistsonsky
The website for our EMBO workshop is live now. Don't miss this opportunity to join us in a meeting that aims gathering all experts working on multicellularity. We will welcome you in the nice Barcelona in October! @multicellgenome.bsky.social @prbb.org @embo.org meetings.embo.org/event/25-mul...
Evolution and origins of multicellularity across the tree of life
The study of the origins and evolution of multicellularity in different lineages has recently captured the attention of many research groups and is fueling the generation of numerous innovative resea…
meetings.embo.org
April 20, 2025 at 4:25 PM
#multicellularity lovers: the website for the EMBO workshop in multicellularity is live. Barcelona is waiting for you! #protistsonsky
Reposted by Katrin Hammerschmidt
Check out our latest work on the evolution of animal genome regulation out today in @nature.com. Nicely summarized below by @ianakim.bsky.social.
www.nature.com/articles/s41...
This is a major output from our ERC-StG project Evocellmap @erc.europa.eu at @crg.eu
www.nature.com/articles/s41...
This is a major output from our ERC-StG project Evocellmap @erc.europa.eu at @crg.eu
May 7, 2025 at 3:32 PM
Check out our latest work on the evolution of animal genome regulation out today in @nature.com. Nicely summarized below by @ianakim.bsky.social.
www.nature.com/articles/s41...
This is a major output from our ERC-StG project Evocellmap @erc.europa.eu at @crg.eu
www.nature.com/articles/s41...
This is a major output from our ERC-StG project Evocellmap @erc.europa.eu at @crg.eu
Reposted by Katrin Hammerschmidt
Check out this amazing segment on Pittsburgh's WTAE about our EvolvingSTEM program. 🙏🏻 to anchor Shannon Perrine for telling our story and showcasing how we engage students grades 6-12 to learn w/ authentic experiments. Teachers and students see themselves as scientists! #SaveNSF #SupportNIH
WTAE filmed us in working with students at Pittsburgh Perry HS, one of more than 30 schools we partner with.
This feature shows the value of NIH & NSF funding at work.
Thanks: teacher Vicki Ammer, Prof. Cassie Quigley from Education, and our team, feat. Colton as local star.
Segment 1:
This feature shows the value of NIH & NSF funding at work.
Thanks: teacher Vicki Ammer, Prof. Cassie Quigley from Education, and our team, feat. Colton as local star.
Segment 1:
May 7, 2025 at 4:38 PM
Check out this amazing segment on Pittsburgh's WTAE about our EvolvingSTEM program. 🙏🏻 to anchor Shannon Perrine for telling our story and showcasing how we engage students grades 6-12 to learn w/ authentic experiments. Teachers and students see themselves as scientists! #SaveNSF #SupportNIH
Reposted by Katrin Hammerschmidt
1/ In our new paper, we explored whether obligate mutualisms can survive abrupt stress via evolutionary rescue.
We found that evolutionary rescue is possible—but it comes at the cost of mutualism. @jfriedman.bsky.social
#microsky #evosky #mevosky
We found that evolutionary rescue is possible—but it comes at the cost of mutualism. @jfriedman.bsky.social
#microsky #evosky #mevosky
Mutualism breakdown underpins evolutionary rescue in an obligate cross-feeding bacterial consortium - Nature Communications
Rapid genetic adaptation to environmental change, or evolutionary rescue, can be constrained by a less adaptable mutualistic partner. Here, the authors explore evolutionary rescue in an obligate mutua...
www.nature.com
April 14, 2025 at 9:34 AM
1/ In our new paper, we explored whether obligate mutualisms can survive abrupt stress via evolutionary rescue.
We found that evolutionary rescue is possible—but it comes at the cost of mutualism. @jfriedman.bsky.social
#microsky #evosky #mevosky
We found that evolutionary rescue is possible—but it comes at the cost of mutualism. @jfriedman.bsky.social
#microsky #evosky #mevosky
Reposted by Katrin Hammerschmidt
Striking new study from @archaeon-alex.bsky.social's lab just out in @science.org on multicellular development induced by compression in Archaea: www.science.org/doi/10.1126/...
Tissue-like multicellular development triggered by mechanical compression in archaea
The advent of clonal multicellularity is a critical evolutionary milestone, seen often in eukaryotes, rarely in bacteria, and only once in archaea. We show that uniaxial compression induces clonal mul...
www.science.org
April 3, 2025 at 6:24 PM
Striking new study from @archaeon-alex.bsky.social's lab just out in @science.org on multicellular development induced by compression in Archaea: www.science.org/doi/10.1126/...
Reposted by Katrin Hammerschmidt
Our new preprint by @nanamikubota.bsky.social shows that P. aeruginosa, and likely many other bacteria carrying filamentous prophages (like V. parahaemolyticus), risk being exploited by these phages in a runaway process that reduces fitness of both host and virus. www.biorxiv.org/content/10.1... 🧵
Filamentous cheater phages drive bacterial and phage populations to lower fitness
Many bacteria carry phage genome(s) in their chromosome (i.e., prophage), and this intertwines the fitness of the bacterium and the phage. Most Pseudomonas aeruginosa strains carry filamentous phages ...
www.biorxiv.org
April 3, 2025 at 5:06 PM
Our new preprint by @nanamikubota.bsky.social shows that P. aeruginosa, and likely many other bacteria carrying filamentous prophages (like V. parahaemolyticus), risk being exploited by these phages in a runaway process that reduces fitness of both host and virus. www.biorxiv.org/content/10.1... 🧵
Reposted by Katrin Hammerschmidt
Super cool new paper by @sshekhr.bsky.social and @wallaceucsf.bsky.social showing that there are collective benefits to simple multicellularity in the *very* charismatic Stentor.
www.nature.com/articles/s41...
Great write up in the NYT by @jack-tamisiea.bsky.social! www.nytimes.com/2025/03/31/s...
www.nature.com/articles/s41...
Great write up in the NYT by @jack-tamisiea.bsky.social! www.nytimes.com/2025/03/31/s...
Eating ‘Family Style’ May Have Set the Stage for Life as We Know It (Gift Article)
Under microscopes, scientists found that giant single-cell organisms were able to vacuum up more food when they are stuck together.
www.nytimes.com
April 1, 2025 at 12:08 PM
Super cool new paper by @sshekhr.bsky.social and @wallaceucsf.bsky.social showing that there are collective benefits to simple multicellularity in the *very* charismatic Stentor.
www.nature.com/articles/s41...
Great write up in the NYT by @jack-tamisiea.bsky.social! www.nytimes.com/2025/03/31/s...
www.nature.com/articles/s41...
Great write up in the NYT by @jack-tamisiea.bsky.social! www.nytimes.com/2025/03/31/s...
Reposted by Katrin Hammerschmidt
1/35 New paper out! @jamesTstroud and I dive into why long-term studies are crucial for understanding evolution. They reveal processes impossible to detect in short timescales and capture rare events that transform our understanding of evolutionary dynamics.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
March 19, 2025 at 7:18 PM
1/35 New paper out! @jamesTstroud and I dive into why long-term studies are crucial for understanding evolution. They reveal processes impossible to detect in short timescales and capture rare events that transform our understanding of evolutionary dynamics.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Katrin Hammerschmidt
We have a 2-year postdoc position available in the Lind Lab at Umeå University, Sweden! Predicting and steering experimental evolution of antibiotic resistance in Pseudomonas aeruginosa. Reposts appreciated.
umu.varbi.com/en/?jobtoken...
umu.varbi.com/en/?jobtoken...
Postdoctor, 2 years, in predicting the evolution of antibiotic resistance
The Department of Molecular Biology seeks a postdoctoral researcher who will work with forecasting and steering experimental evolution of antibiotic resistance. The employment is full-time for two yea
umu.varbi.com
March 13, 2025 at 1:13 PM
We have a 2-year postdoc position available in the Lind Lab at Umeå University, Sweden! Predicting and steering experimental evolution of antibiotic resistance in Pseudomonas aeruginosa. Reposts appreciated.
umu.varbi.com/en/?jobtoken...
umu.varbi.com/en/?jobtoken...
Reposted by Katrin Hammerschmidt
A theoretical biology PhD position at the University of Leiden on the coevolution of aging and sociality with awesome @lottedevries.bsky.social please spread the word! www.universiteitleiden.nl/en/vacancies...
PhD Candidate in Theoretical Biology
The Institute of Environmental Sciences CML and Faculty of Science is looking for:[PhD Candidate in Theoretical Biology]Vacancy number: 15501 We are looking for an enthusiastic and highly motivated Ph...
www.universiteitleiden.nl
March 5, 2025 at 4:20 PM
A theoretical biology PhD position at the University of Leiden on the coevolution of aging and sociality with awesome @lottedevries.bsky.social please spread the word! www.universiteitleiden.nl/en/vacancies...
Reposted by Katrin Hammerschmidt
1/46 Hey folks, we have a new paper out on the MuLTEE. Strap in and I’ll tell you the story of how this “little paper on polyploidy” turned into the most data rich paper our lab has produced, largely thanks to the leadership and work ethic of @kaitong25.bsky.social.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Genome duplication in a long-term multicellularity evolution experiment - Nature
In the Multicellularity Long Term Evolution Experiment, diploid yeast evolve to be tetraploid under selection for larger multicellular size, revealing how whole-genome duplication can arise due to its...
www.nature.com
March 5, 2025 at 11:00 PM
1/46 Hey folks, we have a new paper out on the MuLTEE. Strap in and I’ll tell you the story of how this “little paper on polyploidy” turned into the most data rich paper our lab has produced, largely thanks to the leadership and work ethic of @kaitong25.bsky.social.
www.nature.com/articles/s41...
www.nature.com/articles/s41...