Caenorhabditis elegans may not look much like us, but the primitive worm has a surprising amount in common with humans, biologically speaking—including, as it happens, its response to working out. A new study in BMC Biology analyzed what happens to C. elegans after exercise, finding that their bodies undergo significant physiological changes even after just one session.
Studies have already shown that people benefit from short bursts of exercise, and that in some cases, a very short period of very intense exercise might be more beneficial than a longer but more moderate workout. Research indicates that some of the benefits of working out are immediate—just one workout session has been shown to immediately increase cognitive performance and reduce some of the risk factorsof cardiovascular disease.
Because C. elegans shares some biological characteristics with humans, the species plays a huge role in basic biology research, and understanding what happens to C. elegans during exercise can go a long way toward helping us figure out what happens in our own bodies.
In this study, molecular biologists at Rutgers University exercised the nematodes for five, 30, 60, or 90 minutes by either forcing them to crawl across agar or swim. Using microcalorimeters, they found that swimming was a more rigorous activity for the worms, and that after 90 minutes of activity, they showed physical responses similar to what a mammal would have: increased metabolic rate, fatigue, changes in the metabolization of fat and carbohydrates, and mitochondrial oxidation in muscles.
While it’s fun to imagine scientists hunched over their lab tables acting as worm swim coaches, the study also establishes a method by which future scientists can study the physiology of exercise. Now that we know that 90-minute swim sessions produce similar physiological responses in C. elegans to workouts for mammals, researchers can use this procedure in designing their own studies. Being able to study the effects of exercise in an animal that doesn’t live that long, like C. elegans, means that “life-long effects of exercise can be measured at a cellular, tissue, and organismal level in unprecedented ways,” they write.
Ilya Bobrovskiy, the Australian National University
A bizarre sea creature whose fossils look like a cross between a leaf and a fingerprint may be Earth's oldest known animal, dating back 558 million years.
As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate find in a remote region of Russia: a Dickinsonia fossil with fat molecules still attached. These odd, oval-shaped creatures were soft-bodied, had rib structures running down their sides, and grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in the abstract of a new paper published in the journal Science.
Ilya Bobrovskiy, the Australian National University
Although Dickinsonia fossils were first discovered in South Australia in 1946, researchers lacked the organic matter needed to classify this creature. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution, or the earliest animals on Earth,” senior author Jochen Brocks, an associate professor at ANU, said in a statement.
With the discovery of cholesterol molecules—which are found in almost all animals, but not in other organisms like bacteria and amoebas—scientists can say that Dickinsonia were animals. The creatures swam the seas during the Ediacaran Period, 635 million to 542 million years ago. More complex organisms like mollusks, worms, and sponges didn’t emerge until 20 million years later.
The fossil with fat molecules was found on cliffs near the White Sea in an area of northwest Russia that was so remote that researchers had to take a helicopter to get there. Collecting the samples was a death-defying feat, too.
“I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone, and repeat this process until I found the fossils I was after,” lead author Ilya Bobrovskiy of ANU said. Considering that this find could change our understanding of Earth’s earliest life forms, it seems the risk was worth it.
Romance is rare in the animal kingdom. Instead of wooing their partners before copulating, male ducks force themselves onto females, depositing genetic material with spiky, corkscrew penises. Then, there's tardigrade sex, which is less violent but not exactly heartwarming. Females lay eggs into a husk of dead skin. The male then ejaculates onto the eggs while stroking the female, and the whole process can take up to an hour.
But you can't talk about disturbing mating rituals in nature without mentioning snails. If you're unfamiliar with snail sexuality, you may assume that snail sex falls on the vanilla side: The mollusks, after all, are famous for being slow-moving and they don't even have limbs. But if you have the patience to watch a pair of snails going at it, you'll notice that things get interesting.
The first factor that complicates snail sex is their genitalia. Snails are hermaphrodites, meaning individuals have both a male set and female set of parts, and any two snails can reproduce with each other regardless of sex. But in order for a couple of snails to make little snail babies, one of them needs to take on the role of the female. That's where the love dart comes in.
The love dart, technically called a gypsobelum, isn't exactly the Cupid's arrow the name suggests. It's a nail-clipping-sized spike that snails jab into their partners about 30 minutes before the actual sex act takes place. The sliver is packed with hormones that prepare the receiving snail's body for sperm. Depending on the species, only one snail might release the dart, or they both might in an attempt to avoid becoming the female of the pair. You can watch the action in the video below.
For sex to be successful, both snails must insert their penises into the other's vaginal tracts at the same time. Both snails deposit sperm, and the strength of the love dart ultimately determines whether or not that sperm fertilizes their partner's eggs.
That's assuming the snail survives the little love-stab. In human proportions, the love dart is the equivalent of a 15-inch knife. Fortunately, snails are resilient creatures, and gastropod researcher Joris Koene tells KQED he's only ever seen one snail die from the transfer.
Snails also have a way of making it up to their partners after skewering them with a hormone stick. Their sperm deposit contains a dose of fortifying nutrients, something scientists refer to as a nuptial gift. It may not equal the energy expended during sex, but its enough to give them a small post-coital boost.