Eco-Evo-Devo if life cycles

What is the central idea of eco-evo-devo?

It integrates ecology, evolution, and development to explain how life cycles evolve and how developmental mechanisms shape macroevolutionary patterns.

What does “Ontogeny does not repeat phylogeny — it creates it” mean?

Development shapes evolutionary change; evolution acts by modifying developmental processes rather than simply replaying ancestry.

Why is development more than embryology?

Because development links genes, organisms, and environments across the entire lifespan and across generations, affecting physiology, behaviour, morphology, and evolution.

What is the primary reason life cycles evolve?

To maximize reproductive success under environmental and biological constraints.

What are the four major drivers of life-cycle evolution?

Environmental conditions, resource availability/competition, predation, and dispersal.

Example of environmental influence on life cycles?

Seasonal diapause in invertebrates to match favourable periods.

How do organisms use life cycles to reduce resource competition?

By having different life stages exploit different food sources or habitats (e.g., caterpillar vs butterfly).

How does predation influence life cycle evolution?

Vulnerable stages evolve behaviours or timing that reduce predation risk, such as rapid metamorphosis.

Why is dispersal an important driver of life cycles?

It allows offspring to colonise new habitats, reduce competition, and enhance gene flow.

What is an example of dispersal-driven life-cycle evolution in marine organisms?

Insertion of specialised larval stages (e.g., trochophore, pluteus) that aid in swimming and settlement.

What is the “Darwinian demon”?

A hypothetical organism that can reproduce instantly, infinitely, and never die.

Why can't the Darwinian demon exist?

Because organisms face constraints: limited energy/resources, physiological limits, and natural selection driven by trade-offs.

What is a life-cycle trade-off?

Allocation decisions between growth, survival, and reproduction that shape developmental timing and life-history strategies.

How does evolution modify life cycles at the developmental level?

Through changes in gene expression, developmental timing, and hormonal control.

What is developmental repatterning?

Shifting when and where developmental programs operate, producing new or simplified life cycles.

What is heterochrony?

Evolutionary change in the timing or rate of developmental events.

What aspects of development are most often modified during evolution?

Timing, gene regulation, endocrine signals, and the presence/absence of particular life stages.

What is the ecological approach to life cycles?

Focuses on interactions like predation, competition, and keystone species (e.g., sea otters controlling urchin populations).

What is the eco-evo-devo approach to life cycles?

Looks at how developmental programs vary across species and how modifying these programs leads to different life cycles.

Example of diversity in developmental programs across taxa?

Copepods, jellyfish, worms, and snails each use different developmental modules to produce larvae, metamorphosis, and adult forms.

HOW do life cycles evolve?

By developmental repatterning: changes in timing, gene expression, and hormone regulation.

WHY do life cycles evolve?

To maximise fitness under conditions of environment, resources, predation, dispersal, and developmental constraints.

What constrains life cycle evolution?

Developmental architecture and phylogenetic history.

What links micro-level genetics to macro-evolutionary life-history changes?

Developmental mechanisms (gene networks, hormones, timing changes).