Origin of life
Before there were cells, there were molecules. How did chemical systems begin passing useful abilities to descendants and sustaining their own reproduction?
Biology
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Biological aging
Cells change, tissues lose resilience and organs age at different rates. Which changes drive the others, and how do they become a whole-body process?
Eukaryogenesis
Complex cells with nuclei descended from simpler ancestors. How did their internal compartments, mitochondria, and distinctive cellular organization come together?
Functions of sleep
Sleep is essential, but why do its benefits require a state in which an animal becomes less responsive to its surroundings?
Evolution of multicellularity
Cells have repeatedly evolved into organisms that live and reproduce together. What turns a group of cells into a coherent evolutionary individual?
Sex chromosome evolution
Some lineages keep the same sex chromosomes for vast spans of time; others replace them repeatedly. Why do their evolutionary paths differ so much?
Neural coding
Neural activity carries information, but which aspects of that activity does the brain actually use? A pattern readable by an analyst need not be the pattern used for behavior.
Latitudinal diversity gradient
Many groups contain more species near the equator than near the poles. Which ecological and evolutionary processes generate this large-scale pattern?
Species coexistence
Many species persist together despite competing for resources. Which mechanisms keep any one competitor from excluding the others in real, changing ecosystems?
Genetic architecture of complex traits
Thousands of genetic variants can contribute to a trait, yet finding an association does not reveal how those variants work together to produce it.
Gene regulatory grammar
Cells with similar DNA can activate very different genes. How do regulatory sequences and cellular conditions specify when, where, and how strongly a gene is used?
Developmental robustness
Developing organisms often produce reliable structures despite molecular noise, genetic differences, and environmental changes. How is that reliability achieved?
Regeneration
Some animals rebuild lost body parts, while others mostly form scars. What determines whether damaged tissue can reconstruct an organized, functional structure?
Alzheimer’s disease
Amyloid, tau, immune activity, and other changes accompany Alzheimer’s disease. How do they interact to cause neuronal dysfunction, and why does the course differ between people?
Parkinson’s disease
Parkinson’s disease affects multiple cells and systems, yet people develop it through different combinations of risks. What drives the damaging processes and their spread?
Long COVID
Some people experience persistent or new health problems after SARS-CoV-2 infection. Which biological processes sustain these different conditions?
Tumor dormancy
Cancer cells can persist quietly for years and later form a new tumor. What keeps them dormant, and what allows them to start growing again?
Antibiotic persistence
Some bacteria survive an antibiotic exposure without inheriting resistance to the drug. What allows these persister cells to survive and later resume growth?
Human microbiome causality
Microbial communities differ between people and are associated with many health conditions. Which differences change the host, and which simply reflect other changes?
Animal magnetoreception
Many animals use Earth’s magnetic field to orient themselves. How does that weak field become a signal their nervous systems can use?
Origin of the genetic code
Cells translate genetic sequences into proteins. How did a code and the machinery that reads it arise together?
Origin of viruses
Viruses have remarkably different genomes and structures. Did their major lineages emerge independently, and from what ancestors?
Flowering plant origins
Fossils and DNA offer different timelines for the earliest living flowering-plant lineages. Why do their estimated beginnings still disagree?
Biological homochirality
Life predominantly builds proteins and nucleic acids from particular mirror-image forms. How did those molecular preferences become established?