Key Takeaways:
– Species survival strategies often include relocating or adapting, but dormancy is another option.
– Dormancy can influence the balance of competition among species, allowing more species to coexist in changing environments.
– Animals and plants can stay dormant for periods ranging from a single season to thousands of years.
– Research on nematode worms, Caenorhabditis elegans, identifies the role of dormancy in competition and species survival.
– A primary question is whether organisms that can stay dormant are more resilient to global climate change.
Unpacking Dormancy
When faced with harsh conditions, what do plants and animals do? Most of us would probably guess that they relocate or adapt to their surroundings. But there’s a third, less-known option that some species use to survive – dormancy.
Dormancy is a survival strategy that many organisms use. Like when bears hibernate in winter or certain plants produce seeds that lie dormant in soil over cold months and then sprout in spring. These organisms use dormancy to avoid tough seasonal conditions.
Impressively, some organisms can stay inactive for an incredibly long time – from decades to centuries, and even thousands of years! For instance, the oldest plant seeds that have ever germinated were 2,000-year-old seeds of a Judean date palm tree. There’s also been plant material (although not seeds) brought back to life after over 31,000 years.
Dormancy and Survival
So, does this ability to ‘sleep’ through harsh times protect species from disappearing altogether? It’s been challenging to establish a direct link between dormancy and species survival. But we attempted to make this link by studying a soil-dwelling nematode worm, known as Caenorhabditis elegans. In this worm species, we understand the genetic pathways influencing dormancy very well.
We prepared an experiment with four groups of these worms. Some were more inclined to dormancy, some less. One group couldn’t go dormant at all, while another group, the ‘wild’ type, had moderate dormancy tendencies. We then had these groups of worms battle for food with a common competitor species, another worm called C. briggsae. We then ran millions of computer simulations to see whether one species could wipe out the other, or if they might coexist under different environmental conditions.
Dormancy’s Role in Species Competition
Our findings were fascinating! We discovered that when species lean towards dormancy, they can coexist with competing species under a broader range of environmental factors. In fluctuating environments, species that invested more in dormancy could coexist in various temperatures with their competitor.
This outcome aligns with previous theories, but it’s been challenging to test those theories. The system we used could allow us to explore the role of dormancy in species survival more accurately.
A Question for the Future
Our results beg this question: can species that have a dormant form cope better with the dramatic environmental fluctuations we’re experiencing today? Those that can avoid heatwaves and droughts might indeed be better prepared for our era of unprecedented global changes.
Our next phase of research will investigate this by connecting the lab dynamics we observed to real world dormancy in animals, plants, and microbes. Through this, we aspire to deepen our understanding of dormancy’s critical role in organism survival in the face of environmental uncertainties.