Ecological developmental biology: environmental signals for normal animal development

Area of Science:

• Developmental biology
• Evolutionary biology
• Ecology

Background:

• The environment significantly influences organismal development and evolution.
• Organisms have evolved mechanisms to perceive and respond to environmental signals.
• These signals can be abiotic (temperature, photoperiod) or biotic (predators, food, symbionts).

Purpose of the Study:

• To review the instructive roles of environmental cues in modulating developmental trajectories.
• To explore how environmental signaling facilitates normal, adaptive phenotypes.
• To examine the interplay between environmental cues and symbiotic organisms in development.

Main Methods:

• Review of existing literature on environmental influences on development.
• Analysis of obligatory and facultative environmental cues.
• Examination of symbiotic interactions and their signaling roles.

Main Results:

• Environmental cues, both abiotic and biotic, instruct normal development, producing adaptive phenotypes.
• Obligatory cues are essential for developmental progression (e.g., metamorphosis), sometimes mediated by symbionts (e.g., Wolbachia).
• Facultative cues allow for alternative developmental pathways based on cue presence (e.g., temperature-dependent sex determination).

Conclusions:

• Environmental signaling is fundamental to normal development and co-development with symbionts.
• The capacity to alter phenotypes in response to environmental cues is crucial for evolution, potentially facilitating or constraining it.
• Reciprocal gene expression occurs between hosts and symbionts, mirroring intra-embryonic signaling.