Three days after the arrest of a suspect in the fatal stabbing of four University of Idaho students, authorities have yet to release key details in the case, from whether the suspect knew the victims to what his alleged motive might have been and what finally prompted his arrest.

This article was originally published in Hakai Magazine.

Planet Earth used to be something like a cross between a deep freeze and a car crusher. During vast stretches of the planet’s history, oceans from pole to pole were covered with a blanket of ice a kilometer or so thick. Scientists call this “snowball Earth.”

Some early animals managed to endure this frigid era from roughly 720 million to 580 million years ago, but they had their work cut out for them. Despite their valiant successes, the repeated expansion and contraction of giant ice sheets pulverized the hardy extremophiles’ remains, leaving almost no trace of them in the fossil record and scientists with little to no idea of how they managed to survive.

“It’s basically like having a giant bulldozer,” says Huw Griffiths of the British Antarctic Survey. “The next glacial expansion would have just erased all that and turned it into mush, basically.”

[Read: The origin story of animals is a song of ice and fire]

Despite the lack of direct evidence, thanks to all that glacial churning, Griffiths argues it is reasonable to propose that a diverse range of animal life inhabited snowball Earth. He suggests that this flourishing would have predated the so-called Cambrian explosion, a period about 540 million years ago when a great and unprecedented diversity of animal life emerged on Earth. “It’s not a huge leap of imagination that there were much smaller, simpler things that existed before that,” Griffiths says.

The full picture of animal life during this time is lost, but Griffiths and his colleagues take a stab in a recent paper at trying to figure out what it might have looked like.

The team considered three different frozen periods. The first was the Sturtian snowball Earth, which began about 720 million years ago. It lasted for up to 60 million years. This is a mind-blowingly long time—it’s nearly as long as the period between the end of the dinosaur era and today. Then came the Marinoan snowball Earth, which started 650 million years ago and lasted a mere 15 million years. It was eventually followed by the Gaskiers glaciation, about 580 million years ago. This third glaciation was shorter still and is often called a slushball rather than a snowball Earth because the ice coverage was likely not as extensive.

Though the ice smushed most of the fossils from these periods, scientists have found a handful of remnants. These rare fossils portray the weird animals that existed around the time of the Gaskiers glaciation. Among these ancient slushball-Earth dwellers were the frondomorphs—organisms that looked a bit like fern leaves. Frondomorphs lived fixed to the seafloor beneath the ice and possibly absorbed nutrients from the water as it flowed around them.

Short on direct evidence, Griffiths and his colleagues instead argue that the survival strategies of animals during the great freezes of the past are likely echoed by the life that dwells in the most similar environment on Earth today—Antarctica.

Some modern Antarctic inhabitants such as anemones live upside down, affixed to the underside of the sea ice. One of the favorite feeding strategies of krill is grazing microorganisms on this upturned plane. Perhaps early animals foraged and found shelter in such locations, too, Griffiths and his colleagues suggest.

It’s also possible that the waxing and waning of sea ice introduced algae or other microorganisms living on the ice into seawater, allowing them to bloom, which might have provided food for other early animals.

One of the challenges that inhabitants of a snowball Earth faced was the possible lack of oxygen, both because the oxygen levels in the air were low and because there was limited mixing from the atmosphere into the water. But oxygenated meltwater high in the water column might have supported animals that depended on it. Some denizens that live on the Antarctic seafloor today, such as certain species of feather star, solve this problem by relying on water currents to bring a steady flow of oxygen and nutrients from the small areas of open water at the surface to deep below the ice shelves. There’s no reason to think this didn’t happen during the Gaskiers slushball Earth period too.

[Read: Watching Venezuela’s last glacier disappear]

“We are really talking about very basic forms of life … but at the time, that’s all you’d have needed to be king of the animals,” says Griffiths.

Alongside frondomorphs, the seafloor might also have been inhabited by sponges. Some fossil evidence of sponges dates back to well before the Sturtian snowball Earth, though there is some debate over this, says Griffiths.

Ashleigh Hood, a sedimentologist at the University of Melbourne, in Australia, who was not involved in the research, jokes that “everyone, including us, has their oldest sponge that they’ve found in the record, and no one else believes them.”

Some modern sponges live symbiotically with bacteria, which may help them access nutrients when other food is scarce. “That’s probably based off a survival strategy they had really early on in their history,” Hood suggests.

Andrew Stewart, an assistant curator at the Museum of New Zealand Te Papa Tongarewa, who also wasn’t involved in the paper, has studied countless species from harsh Antarctic environments. Many of these organisms cope in incredibly dark, cold, or chemically toxic places. For Stewart, Antarctic extremophiles are a reminder of how robust life on Earth really is—and perhaps always has been.

“It’s just the most amazing place,” he says. “You go, ‘No, bollocks, nothing can survive there!’ Well, actually, it can.”

In the United States, sports can dominate kids’ whole lives. Weekends are filled with games, tournaments, and travel. For the most talented, participation in club teams can lead to state teams, followed by national ones. Then, with the pursuit of college sport scholarships, and eventually playing in the NCAA, a teenager’s entire identity can become intertwined with athletic success. In chasing that dream, “a young person starts giving up all the other aspects of their life,” Francesca Cavallerio, a sports psychologist and lecturer at Anglia Ruskin University, in the United Kingdom, told me.

That single-mindedness can become a hindrance when athletes realize that they’re not going to turn pro. According to the NCAA, less than 2 percent of college athletes go on to play professional sports. (Even if they make it that far, the average professional career length in football, basketball, baseball, and ice hockey is three to five years.) Many young athletes don’t realize what sports provided until that point: the security of having a defined role in a closed world with rules and guidance. After graduation, an uncertain future might await. “All the great transferable skills that you gain as an elite athlete can be extremely useful, but only if you actually find a new path, a new goal,” Elodie Wendling, a researcher in the University of Florida’s department of sports management, told me.

Transitioning out of a linear education system into regular adult life can be a challenge for any 20-something; adding in the end of a long sports career can make it even harder. At an age when most people are embarking on their careers, elite athletes are already wrapping one up, and facing issues that most people don’t confront until later in life. Retired athletes, much like the rest of us, would benefit from having more than one identity in life—they’re just forced to learn this lesson young.

Post-sports life comes with many profound adjustments, but also trivial ones. “I was so used to eating every night grilled chicken, rice and vegetables, and a salad, and one piece of bread and water,” Savannah Jordan, a former professional soccer player, told me. Jordan was a natural athlete in a competitive family, dabbling in several sports before soccer took her to the University of Florida and a two-year stint playing professionally. From the age of 13, she felt like the sport was a full-time job. Jordan’s every meal choice was controlled by coaches. “Now I go out and look at a menu, and my natural instinct is that I can't have any of [those foods], because my mind was so trained,” she said.

After retiring, Jordan understood that she had the freedom of personal choice. But that wasn’t easy either: So many elements of her life as a soccer player—right down to when to eat and sleep—had been set in a concrete schedule. Jordan had also gone without certain rituals, like proms, sleepovers, and parties; she didn’t have much of a social life at all. Instead, friendships came ready-made, because teammates spend much of their time together. They’d joke with one another: “You’re my friend because you have to be my friend,” Jordan said. “When I got out into the real world, it’s like, what social groups do I fit into.”

Perhaps surprisingly, exercise and physical health can be a challenge for some former athletes after college. “There’s an assumption that athletes by nature of being athletes know how to be active,” Erin Reifsteck, an associate professor in the department of kinesiology at the University of North Carolina at Greensboro, told me by email. But training for a sport isn’t the same thing as exercise for health. “The culture of sport often reinforces certain values and norms, like sacrificing your body for the sake of athletic performance,” Reifsteck said. “Physical activity in this context can be viewed as very intense and even painful, which is maybe not the most ideal perception.” In one study, former Division I athletes exercised less, weighed more, and were more likely to have osteoarthritis (potentially stemming from long-ago injuries) compared with people who had competed in club, intramural, or recreational sports in college.

[Read: Finding new meaning after an Olympic career]

One key to helping athletes adjust to retirement might be supporting them better during college: a formative period for any young person, and one when sporting demands might kick into overdrive. “There’s just not enough support at the college level to prepare athletes for life after sport,” Wendling said. In the Pac-12—a major athletic conference in college sports—athletes spend more than 50 hours a week in sport-related activities, Eddie Comeaux, the executive director of the Center for Athletes’ Rights and Equity at UC Riverside, told me.

On top of that, they deal with “the mental fatigue, the physical exhaustion, the nagging injuries,” Comeaux said. “When you think about the demands of their coaches, the demands of their sport, the extensive travel during the season, it’s less likely that athletes will spend time in the classroom.” A 2019 NCAA study of 22,000 student athletes showed that Division I basketball and baseball players spend an average of more than two days per week away from campus during their competitive season. The same study also showed that recently, athletes in many sports have spent less time socializing or relaxing during the athletic season—from 20 hours a week in 2010 to just 15 hours in 2019.

Many college athletes might not have time to do the things both inside and outside the lecture hall that prepare students for life after graduation: applying for internships, joining non-sports clubs, studying abroad. In the NCAA study, when the student athletes were asked what they wished coaches and athletic administrators would talk more about, the most common response—from 41 percent of male athletes and 61 percent of female athletes—was preparing for a non-sporting career after college. In one of Wendling’s studies, funded by an NCAA grant, 55 percent of the more than 500 former college athletes interviewed felt confused about what to do after college or had not yet established plans for their next career.

Young athletes are typically conditioned to have a singular focus on their sport from an early age, with the tacit belief that this is the only route to success. But a little more personal freedom might not be antithetical to maximizing athletic performance. Wendling is researching how having career commitments outside a sport can increase athletes’ well-being. Her hypothesis is that this would also improve athletic performance. Whether or not that proves correct, perhaps a better quality of life would be its own reward for a young athlete in the twilight of their career.

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