Robert Pittman, NOAA via Wikimedia Commons // Public Domain
Robert Pittman, NOAA via Wikimedia Commons // Public Domain

Orca Genome Reveals a Cultural History of the Species

Robert Pittman, NOAA via Wikimedia Commons // Public Domain
Robert Pittman, NOAA via Wikimedia Commons // Public Domain

When we talk about "culture," we’re almost always talking about people. But many biologists argue that non-human animals have culture too, and that their cultures, like our own, can shape and be shaped by the environment and genes. Researchers who have sequenced the orca genome say the cetaceans’ DNA tells a tale of culture, socialization, and dispersal through the world’s oceans. The findings are published this week in the journal Nature Communications. 

The study of relationships between culture and genes is a relatively new and limited field, the authors note, so "our understanding of the complex interaction between ecology, culture, adaptation and reproductive isolation at a genome-wide level has long suffered from deficiency of genome-wide data, and, conceptually, from the almost-exclusive focus on these processes in humans and thus a lack of comparative data from other species.” 

Enter the orca (Orcinus orca): a highly social species that has managed to find itself at home in oceans from the Arctic to Antarctica. The orca is, the authors write, “together with humans … one of the most cosmopolitan mammals.” 

"Did somebody say 'cosmopolitan'?" Image credit: John Durban, NOAA Southwest Fisheries Science Center

Orcas’ success is due in part to their practice of sending out small groups to explore and then inhabit unfamiliar territory. Their long life spans and matriarchal social structure also allow settlers to pass on what they’ve learned to the next generation, which makes it more likely that a new outpost will survive. Over time, these little groups, or ecotypes, adapt to their environment, changing their diets and developing new hunting techniques. In other words, they create a new culture.   

"There goes the neighborhood." Image credit: John Durban, NOAA Southwest Fisheries Science Center

To get a more molecular look at these ecotypes, an international team of scientists set out to sequence the orca’s genome. They used biopsy darts to collect tissue samples from 50 wild orcas from around the world. Some of the orcas belonged to ecotypes that ate mostly fish. Others were penguin specialists, and still others preyed primarily on marine mammals like seals.

Analysis of the orcas’ DNA revealed a familiar story: a tiny reflection in genetic code of the orcas’ natural history—and our own. Tracing patterns of gene expression showed that, across the board, a population shrink (often called a "bottleneck") led to the creation of a new outpost, which, once established, was followed by a population boom as the orcas adapted to their new home. 

This orca is doing just fine. The penguin, on the other hand … Image credit: Holly Fearnbach, NOAA Southwest Fisheries Science Center

Each ecotype has a slightly different genetic makeup than that of the group from which it split, but the authors note that this is something of a chicken-or-the-egg issue: “As with studies on modern humans, it is difficult to demonstrate a causal association between cultural differences and selection on specific genes.”

Did the settlers thrive in their new environment because they had the genes that would allow them to safely change their diet? Or did the change in diet prompt a shift in genetic makeup? That remains to be seen. This is just the first page of a new chapter in science history. 

“Given these findings,” the authors write, “the almost-exclusive focus on humans by studies of the interaction of culture and genes should be expanded, and exploration of culture-genome coevolution models in suitable non-human animal systems encouraged.”

Pig Island: Sun, Sand, and Swine Await You in the Bahamas

When most people visit the Bahamas, they’re thinking about a vacation filled with sun, sand, and swimming—not swine. But you can get all four of those things if you visit Big Major Cay.

Big Major Cay, also now known as “Pig Island” for obvious reasons, is part of the Exuma Cays in the Bahamas. Exuma includes private islands owned by Johnny Depp, Tyler Perry, Faith Hill and Tim McGraw, and David Copperfield. Despite all of the local star power, the real attraction seems to be the family of feral pigs that has established Big Major Cay as their own. It’s hard to say how many are there—some reports say it’s a family of eight, while others say the numbers are up to 40. However big the band of roaming pigs is, none of them are shy: Their chief means of survival seems to be to swim right up to boats and beg for food, which the charmed tourists are happy to provide (although there are guidelines about the best way of feeding the pigs).

No one knows exactly how the pigs got there, but there are plenty of theories. Among them: 1) A nearby resort purposely released them more than a decade ago, hoping to attract tourists. 2) Sailors dropped them off on the island, intending to dine on pork once they were able to dock for a longer of period of time. For one reason or another, the sailors never returned. 3) They’re descendants of domesticated pigs from a nearby island. When residents complained about the original domesticated pigs, their owners solved the problem by dropping them off at Big Major Cay, which was uninhabited. 4) The pigs survived a shipwreck. The ship’s passengers did not.

The purposeful tourist trap theory is probably the least likely—VICE reports that the James Bond movie Thunderball was shot on a neighboring island in the 1960s, and the swimming swine were there then.

Though multiple articles reference how “adorable” the pigs are, don’t be fooled. One captain warns, “They’ll eat anything and everything—including fingers.”

Here they are in action in a video from National Geographic:

Christine Colby
job secrets
13 Secrets From the Ravenmaster at the Tower of London
Christine Colby
Christine Colby

Christopher Skaife is a Yeoman Warder at the Tower of London, an ancient fortress that has been used as a jail, royal residence, and more. There are 37 Yeoman Warders, popularly known as Beefeaters, but Skaife has what might be the coolest title of them all: He is the Ravenmaster. His job is to maintain the health and safety of the flock of ravens (also called an “unkindness” or a “conspiracy”) that live within the Tower walls. According to a foreboding legend with many variations, if there aren’t at least six ravens living within the Tower, both the Tower and the monarchy will fall. (No pressure, Chris!)

Skaife has worked at the Tower for 11 years, and has many stories to tell. Recently, Mental Floss visited him to learn more about his life in service of the ravens.


All Yeoman Warders must have at least 22 years of military service to qualify for the position and have earned a good-conduct medal. Skaife served for 24 years—he was a machine-gun specialist and is an expert in survival and interrogation resistance. He is also a qualified falconer.

Skaife started out as a regular Yeoman Warder who had no particular experience with birds. The Ravenmaster at the time "saw something in him," Skaife says, and introduced him to the ravens, who apparently liked him—and the rest is history. He did, however, have to complete a five-year apprenticeship with the previous Ravenmaster.


The Tower of London photographed at night
Christine Colby

As tradition going back 700 years, all Yeoman Warders and their families live within the Tower walls. Right now about 150 people, including a doctor and a chaplain, claim the Tower of London as their home address.


Skaife used to live next to the Bloody Tower, but had to move to a different apartment within the grounds because his first one was “too haunted.” He doesn’t really believe in ghosts, he says, but does put stock in “echoes of the past.” He once spoke to a little girl who was sitting near the raven cages, and when he turned around, she had disappeared. He also claims that things in his apartment inexplicably move around, particularly Christmas-related items.


The Ravenmaster at the Tower of London bending down to feed one of his ravens
Christine Colby

The birds are fed nuts, berries, fruit, mice, rats, chicken, and blood-soaked biscuits. (“And what they nick off the tourists,” Skaife says.) He has also seen a raven attack and kill a pigeon in three minutes.


Each evening, Skaife whistles a special tone to call the ravens to bed—they’re tucked into spacious, airy cages to protect them from predators such as foxes.


One of the ravens doesn’t join the others in their nighttime lodgings. Merlina, the star raven, is a bit friendlier to humans but doesn’t get on with the rest of the birds. She has her own private box inside the Queen’s House, which she reaches by climbing a tiny ladder.


Ravens normally pair off for life, but one of the birds at the Tower, Munin, has managed to get her first two mates killed. With both, she lured them high atop the White Tower, higher than they were capable of flying down from, since their wings are kept trimmed. Husband #1 fell to his death. The second one had better luck coasting down on his wings, but went too far and fell into the Thames, where he drowned. Munin is now partnered with a much younger male.


Only the Yeoman Warders, their families, and invited guests can go inside a secret pub on the Tower grounds. Naturally, the Yeoman Warder’s Club offers Beefeater Bitter beer and Beefeater gin. It’s lavishly decorated in police and military memorabilia, such as patches from U.S. police departments. There is also an area by the bar where a section of the wall has been dug into and encased in glass, showing items found in an archaeological excavation of the moat, such as soldiers’ discarded clay pipes, a cannonball, and some mouse skeletons.


The Byward Tower, which was built in the 13th century by King Henry III, is now used as the main entrance to the Tower for visitors. It has a secret glass brick set into the wall that most people don’t notice. When you peer inside, you’ll see it contains a human hand (presumably fake). It was put in there at some point as a bit of a joke to scare children, but ended up being walled in from the other side, so is now in there permanently.


Skaife considers himself primarily a storyteller, and loves sharing tales of what he calls “Victorian melodrama.” In addition to his work at the Tower, he also runs Grave Matters, a Facebook page and a blog, as a collaboration with medical historian and writer Dr. Lindsey Fitzharris. Together they post about the history of executions, torture, and punishment.


2013’s Muppets Most Wanted was the first major film to shoot inside the Tower walls. At the Yeoman Warder’s Club, you can still sit in the same booth the Muppets occupied while they were in the pub.


Ravens are very clever and known for stealing things from tourists, especially coins. They will strut around with the coin in their beak and then bury it, while trying to hide the site from the other birds.


Skaife, who’s covered in scars from raven bites, says, “They don’t like humans at all unless they’re dying or dead. Although they do love eyes.” He once had a Twitter follower, who is an organ donor, offer his eyes to the ravens after his death. Skaife declined.

This story first ran in 2015.


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