Tardigrades are metazoans, microscopic members of Kingdom Animalia. Their bear-like shape has led to the nickname “water bears.” Tardigrades date back to the Cambrian and are found on every continent. Tardigrada is a phylum encompassing a variety of species.
Experiments have shown that tardigrades are the only creatures known to survive the vacuum of space! This is due to their ability to undergo cryptobiosis, a state of suspended animation in which they shrivel into a dehydrated form and suspend all metabolic activity. Tardigrades use their cryptobiotic abilities to survive conditions like freezing, evaporation, radiation, high heat, and extreme pressures. Scientists are intrigued by cryptobiosis as a means of investigating the mechanisms, like DNA repair, that allow survival in such conditions.
Despite their incredible cryptobiotic abilities and their ubiquitous presence all over the planet, not much is known about tardigrade ecology or evolution.. Little is known about how tardigrades are affected by climate change, anthropogenic disturbance, or habitat loss. With large wildlife like deer, it’s easy to observe how human activity and habitat fragmentation affects their abundances. Since tardigrades are invisible to the naked eye, it’s more difficult to detect how their populations may be affected. Similarly, little is known about the evolution of cryptobiosis. Researchers have posed various theories on what environmental factors select drove the evolution of cryptobiosis, and even how many times cryptobiosis evolved. For these reasons, tardigrades are excellent subjects for undergraduate research projects! Using tardigrades as a model system, we can conduct real, hands-on research investigate fascinating questions that address some of these gaps in scientific knowledge and offer insights into ecological and evolutionary mechanisms.
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