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
This is a beautiful paper examining the molecular genetics of facultative multicellularity in a marine black yeast.
I also love that they figure out the ecological context for the behavior (MC form when in sponges, where there are nutrients, & uni when starving!).
www.nature.com/articles/s41...
I also love that they figure out the ecological context for the behavior (MC form when in sponges, where there are nutrients, & uni when starving!).
www.nature.com/articles/s41...
Client Challenge
www.nature.com
January 13, 2026 at 3:00 PM
This is a beautiful paper examining the molecular genetics of facultative multicellularity in a marine black yeast.
I also love that they figure out the ecological context for the behavior (MC form when in sponges, where there are nutrients, & uni when starving!).
www.nature.com/articles/s41...
I also love that they figure out the ecological context for the behavior (MC form when in sponges, where there are nutrients, & uni when starving!).
www.nature.com/articles/s41...
Reposted by Katrin Hammerschmidt
Very cool paper by Jyotsna Kalathera et al. from @iamsamayp.bsky.social 's-lab on
Bottleneck size drives the evolution of
cooperative traits in an aggregative multicellular
myxobacterium
just out @plosbiology.org
Congratulations to all coauthors.
journals.plos.org/plosbiology/...
Bottleneck size drives the evolution of
cooperative traits in an aggregative multicellular
myxobacterium
just out @plosbiology.org
Congratulations to all coauthors.
journals.plos.org/plosbiology/...
Bottleneck size drives the evolution of cooperative traits in an aggregative multicellular myxobacterium
Population bottlenecks shape the evolution of cooperative traits in Myxococcus xanthus through life cycle trade-offs. This study shows that stringent bottlenecks favor growth and sporulation, while re...
journals.plos.org
January 7, 2026 at 11:56 AM
Very cool paper by Jyotsna Kalathera et al. from @iamsamayp.bsky.social 's-lab on
Bottleneck size drives the evolution of
cooperative traits in an aggregative multicellular
myxobacterium
just out @plosbiology.org
Congratulations to all coauthors.
journals.plos.org/plosbiology/...
Bottleneck size drives the evolution of
cooperative traits in an aggregative multicellular
myxobacterium
just out @plosbiology.org
Congratulations to all coauthors.
journals.plos.org/plosbiology/...
Reposted by Katrin Hammerschmidt
Cooperation is a universal feature of complex systems, from the origins of life and microbiomes to societies. What universal patterns can be found in these systems? Here's our new @pnas.org paper. @jordipinero.bsky.social @artemyte.bsky.social @sfiscience.bsky.social www.pnas.org/doi/epdf/10....
December 19, 2025 at 6:44 PM
Cooperation is a universal feature of complex systems, from the origins of life and microbiomes to societies. What universal patterns can be found in these systems? Here's our new @pnas.org paper. @jordipinero.bsky.social @artemyte.bsky.social @sfiscience.bsky.social www.pnas.org/doi/epdf/10....
Reposted by Katrin Hammerschmidt
Reposted by Katrin Hammerschmidt
in 2013, Elio was so fascinated by the 'heterologous multicellularity' of 𝘊𝘩𝘭𝘰𝘳𝘰𝘤𝘩𝘳𝘰𝘮𝘢𝘵𝘪𝘶𝘮 𝘢𝘨𝘨𝘳𝘦𝘨𝘢𝘵𝘶𝘮 that he chose a cross-section to celebrate STC's 10th anniversary 🙂
👉 smallthingsconsidered.blog/schaechter/2...
#MicroSky
👉 smallthingsconsidered.blog/schaechter/2...
#MicroSky
December 19, 2025 at 3:55 PM
in 2013, Elio was so fascinated by the 'heterologous multicellularity' of 𝘊𝘩𝘭𝘰𝘳𝘰𝘤𝘩𝘳𝘰𝘮𝘢𝘵𝘪𝘶𝘮 𝘢𝘨𝘨𝘳𝘦𝘨𝘢𝘵𝘶𝘮 that he chose a cross-section to celebrate STC's 10th anniversary 🙂
👉 smallthingsconsidered.blog/schaechter/2...
#MicroSky
👉 smallthingsconsidered.blog/schaechter/2...
#MicroSky
Reposted by Katrin Hammerschmidt
🚨 What if evolution is the ”law”… and networks are the machines that do the work?
In this paper (just published) I try to formalize how living systems are non-equilibrium, information-processing, adaptive matter. With a great biological flavor! 🧪🌐🌍🧬🦠
👉 iopscience.iop.org/article/10.1...
🧵 1/
In this paper (just published) I try to formalize how living systems are non-equilibrium, information-processing, adaptive matter. With a great biological flavor! 🧪🌐🌍🧬🦠
👉 iopscience.iop.org/article/10.1...
🧵 1/
December 16, 2025 at 9:04 AM
🚨 What if evolution is the ”law”… and networks are the machines that do the work?
In this paper (just published) I try to formalize how living systems are non-equilibrium, information-processing, adaptive matter. With a great biological flavor! 🧪🌐🌍🧬🦠
👉 iopscience.iop.org/article/10.1...
🧵 1/
In this paper (just published) I try to formalize how living systems are non-equilibrium, information-processing, adaptive matter. With a great biological flavor! 🧪🌐🌍🧬🦠
👉 iopscience.iop.org/article/10.1...
🧵 1/
Reposted by Katrin Hammerschmidt
How do simple cells make complex patterns? We discovered a key piece in cyanobacteria—an ancient enzyme repurposed to activate a pattern-forming signal. A conserved signaling strategy, showing how nature reuses tools to build multicellularity. www.cell.com/iscience/ful...
Co-option of an ancestral peptidase controls developmental patterning in multicellular cyanobacteria
Developmental biology
www.cell.com
December 17, 2025 at 8:44 AM
How do simple cells make complex patterns? We discovered a key piece in cyanobacteria—an ancient enzyme repurposed to activate a pattern-forming signal. A conserved signaling strategy, showing how nature reuses tools to build multicellularity. www.cell.com/iscience/ful...
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