Segregation Distorter mechanism
A selfish chromosome in fruit flies disables competing sperm. How does its genetic machinery cause that selective failure?
Biology
Gravity sensing in plants
Roots and shoots can tell which way gravity points. How do settling structures inside cells become a directional growth signal?
Speciation with gene flow
New species can diverge while exchanging genes. How do reproductive barriers combine to sustain separation?
Arbuscule maintenance
Does nutrient delivery by a fungal branch inside a root influence how long the plant maintains it?
Coral bleaching
Heat stress can disrupt the partnership between corals and their photosynthetic symbionts. Which cellular pathways cause symbiont loss in different conditions?
Biological carbon-pump efficiency
Ocean plankton capture carbon, but much is recycled before it reaches depth. What determines how much carbon from different organisms survives that journey?
Bergmann’s rule
Many birds are larger in colder places, but the pattern varies. Which inherited and developmental mechanisms create these geographic size differences?
Great Ordovician Biodiversification Event
Marine diversity expanded dramatically around the Ordovician. How did ecological change, nutrient cycling and climate interact to produce that diversification?
Nitrogenase catalytic mechanism
Nitrogenase converts nitrogen gas into ammonia that life can use. Which atomic reaction pathway accounts for its observed chemistry?
Spore hydration
Dormant bacterial spores take up water as they restart. Does GerAB provide a water route in Bacillus subtilis?
Oxytricha genome rearrangement
Oxytricha rebuilds its working genome from scrambled DNA segments. How do RNA instructions become correctly ordered DNA joins?
De novo gene birth
New protein-coding genes can arise from DNA that did not previously encode a protein. Which ones become useful and persist through evolution?
Malaria relapse
Plasmodium vivax can remain dormant in the liver before causing malaria again. What makes the parasite restart replication?
Multiple sclerosis relapse
EBV-related immune activity can rise before multiple sclerosis relapses. Does it drive new brain and spinal-cord lesions, amplify another trigger, or accompany it?
Japanese eel migration
Japanese eel larvae travel from the West Mariana spawning region to East Asia. Which routes and changing depths lead to each coastal arrival?
Endometriosis
Endometriosis involves lasting lesions outside the uterus. Which uterine-cell and immune changes help initiate them, rather than result from established disease?
Comb-jelly nervous systems
Did comb-jelly neurons share an origin with other animal neurons, or were nervous systems assembled independently from older cellular components?
Mycorrhizal defence signalling
Aphid attack on one bean plant can change a neighbour’s defences in fungal-network experiments. What carries the cue between them?
Root hydrotropism
A root can curve toward a wetter patch of soil. What first tells its growing cells that one side has more available water than the other?
S-RNase specificity
A Petunia flower can stop its own pollen while accepting pollen with a different mating type. How does a small team of pollen proteins distinguish so many versions of the same toxic enzyme?
Saccharibacteria host recognition
A tiny Saccharibacterium survives by attaching to another bacterium. Which molecular handshake decides whether that bacterial partner is usable?
Paulinella protein import
A Paulinella amoeba carries a photosynthetic compartment descended from a bacterium. It makes essential proteins outside that compartment—how do those proteins cross its inner membrane to work inside?
Lichen morphogenesis
A yellow lichen on bark has organized layers built by organisms with separate genomes. What makes its fungus and alga assemble that shared body?
Outer membrane vesicle cargo selection
A bacterium releases membrane bubbles whose protein contents differ from its own envelope. What determines which proteins leave in those bubbles and which stay behind?