Multispecies interactions shape the transition to multicellularity

Area of Science:

• Evolutionary biology
• Ecology
• Microbiology

Background:

• The evolution of multicellularity is a pivotal event in life's history, enabling complex adaptations.
• Most research on multicellularity overlooks the role of interspecific competition.
• Understanding the ecological context is crucial for the origin and diversification of life.

Purpose of the Study:

• To investigate how interspecific competition influences the emergence of multicellularity.
• To examine the impact of multicellularity on community dynamics between yeast species.

Main Methods:

• Experimental evolution using two yeast species: Saccharomyces cerevisiae and Kluyveromyces lactis.
• Selection for multicellularity was driven by enhanced settling ability.
• Monitoring of population dynamics and community composition in monocultures and cocultures.

Main Results:

• The presence of competing yeast species significantly slowed the rate of multicellularity evolution.
• Multicellular Kluyveromyces lactis emerged faster in monocultures than in cocultures with Saccharomyces cerevisiae.
• The evolution of multicellularity altered interspecific competitive dynamics, potentially through increased intraspecific cooperation.

Conclusions:

• Ecological context, specifically interspecific competition, critically shapes the evolution of multicellularity.
• The transition to multicellularity can lead to significant shifts in community structure and function.
• Cooperation and competition at multiple biological scales are integral to the origin and maintenance of multicellular life.