Category: Evolution

Bold, Intelligent, Freedom-Loving Octopus “Inky” Escapes to the Sea

OctopusInkyEyesCaptors2016-05-16.jpgInky eyes captors. Source of photo: online version of the NYT article quoted and cited below.

(p. A8) It was an audacious nighttime escape.

After busting through an enclosure, the nimble contortionist appears to have quietly crossed the floor, slithered through a narrow drain hole about six inches in diameter and jumped into the sea. Then he disappeared.
This was no Houdini, but rather a common New Zealand octopus called Inky, about the size of a soccer ball.
The breakout at the National Aquarium of New Zealand in Napier, which has captured the imagination of New Zealanders and made headlines around the world, apparently began when Inky slipped through a small gap at the top of his tank.
Octopus tracks suggest he then scampered eight feet across the floor and slid down a 164-foot-long drainpipe that dropped him into Hawke’s Bay, on the east coast of North Island, according to reports in New Zealand’s news media.
. . .
Alix Harvey, an aquarist at the Marine Biological Association in England, noted that octopuses, members of a class of marine animals including squid and cuttlefish called Cephalopoda, have shown themselves to be adept at escaping through spaces as small as a coin, constrained only by their beaks, the only inflexible part of their bodies.
Ms. Harvey said that octopuses had also been documented opening jars and sneaking through tiny holes on boats, and that they could deflect predators by spraying an ink that lingers in the water and acts as a decoy. Some have been seen hauling coconut shells to build underwater shelters.
. . .
She continued, “They have a complex brain, have excellent eyesight, and research suggests they have an ability to learn and form mental maps.”
. . .
Octopuses’ intelligence, she said, was partly an evolutionary response to their habitation in complex environments such as coral reefs, in which the animals need to hide from predators and sneak up on their prey.

For the full story, see:
DAN BILEFSKY. “Octopus Escapes From an Aquarium in New Zealand.” The New York Times (Thurs., APRIL 14, 2016): A8.
(Note: ellipses added.)
(Note: the online version of the story has the date APRIL 13, 2016, and has the title “Inky the Octopus Escapes From a New Zealand Aquarium.”)

Discovery of Proof of Concept of Transition from Fish to Land Vertebrates

(p. A4) It’s one of the most famous chapters in evolution, so familiar that it regularly inspires New Yorker cartoons: Some 375 million years ago, our ancestors emerged from the sea, evolving from swimming fish to vertebrates that walked on land.
Scientists still puzzle over exactly how the transition from sea to land took place. For the most part, they’ve had to rely on information gleaned from fossils of some of the intermediate species.
But now a team of researchers has found a remarkable parallel to one of evolution’s signature events. In a cave in Thailand, they’ve discovered that a blind fish walks the way land vertebrates do.
. . .
The researchers published their study on Thursday [March 24, 2016] in the journal Scientific Reports.
Dr. Flammang said that the waterfall-climbing cave fish eventually might give scientists hints about how fish originally arrived on land. “The physics are the same,” she said.

For the full story, see:
Carl Zimmer. “Researchers Find Fish That Walks the Way Land Vertebrates Do.” The New York Times (Fri., MARCH 25, 2016): A4.
(Note: ellipsis, and bracketed date, added.)
(Note: the online version of the story has the date MARCH 24, 2016.)

The academic article presenting the research summarized above, is:
Flammang, Brooke E., Apinun Suvarnaraksha, Julie Markiewicz, and Daphne Soares. “Tetrapod-Like Pelvic Girdle in a Walking Cavefish.” Scientific Reports 6 (March 24, 2016): 23711.

Haramiyids May Be Missing Link Between Reptiles and Mammals

(p. A17) With technologies like CT scans and 3-D printing, a team of scientists reported on Monday that it had solved a mystery about the family tree of mammals that started with a single tooth a century and a half ago.
The tooth, found in Germany in 1847, was tiny and distinctive in shape — not quite reptile, not quite mammal. More fossils of that kind were found around Europe, but always just single teeth. Scientists named this group of animals haramiyids — Arabic for “trickster.”
The teeth were embedded in rocks as old as 210 million years, an era in which ancestors of the first mammals were evolving.
. . .
What was unclear was whether Haramiyavia was a direct part of the family tree of mammals — that would push the emergence of mammals back to more than 200 million years ago — or an evolutionary branch that split off before common ancestors of mammals emerged, the view of paleontologists who believe that the first mammals evolved 170 million to 160 million years ago.

For the full story, see:
KENNETH CHANG. “Jawbone in Rock May Solve Mammal Family Mystery.” The New York Times (Tues., NOV. 17, 2015): A17.
(Note: ellipsis added.)
(Note: the online version of the story has the date NOV. 16, 2015, and has the title “Jawbone in Rock May Clear Up a Mammal Family Mystery.”)

Denisovans May Have Mated with As-Yet-Undiscovered Hominin Species

(p. A17) A tooth fossil discovered in a Siberian cave has yielded DNA from a vanished branch of the human tree, mysterious cousins called the Denisovans, scientists said Monday [November 16, 2015].
Their analysis pushes back the oldest known evidence for Denisovans by 60,000 years, suggesting that the species was able to thrive in harsh climates for thousands of generations. The results also suggest that the Denisovans may have bred with other ancient hominins, relatives of modern humans whom science has yet to discover.
Todd Disotell, a molecular anthropologist at New York University who was not involved in the new study, said the report added to growing evidence that our species kept company with many near relatives over the past million years.
. . .
Some of the DNA in the Denisova 8 tooth hints at an even older interbreeding. While most of the genetic material in the tooth bears a close kinship with Neanderthals, some of it seems only distantly related to Neanderthal or human DNA.
One possible explanation, Dr. Paabo said in an interview, is that Denisovans interbred with another hominin species that lived in Asia. It is conceivable that this hominin was a species already known from fossil discoveries, such as Homo erectus. But it could also be a related species.
“If you would have told me five years ago I would be talking about species we don’t have any fossils for, I would have thought you were crazy,” Dr. Disotell said.

For the full story, see:
CARL ZIMMER. “Tooth in Cave Adds Earlier Evidence of Some Very Old Cousins, the Denisovans.” The New York Times (Tues., NOV. 17, 2015): A6.
(Note: ellipsis, and bracketed date, added.)
(Note: the online version of the story has the date NOV. 16, 2015, and has the title “In a Tooth, DNA From Some Very Old Cousins, the Denisovans.”)

Scientific Insight Requires Hard Work More than Easy Epiphany

(p. A21) The myth of the finches obscures the qualities that were really responsible for Darwin’s success: the grit to formulate his theory and gather evidence for it; the creativity to seek signs of evolution in existing animals, rather than, as others did, in the fossil record; and the open-mindedness to drop his belief in creationism when the evidence against it piled up.
The mythical stories we tell about our heroes are always more romantic and often more palatable than the truth. But in science, at least, they are destructive, in that they promote false conceptions of the evolution of scientific thought.
Of the tale of Newton and the apple, the historian Richard S. Westfall wrote, “The story vulgarizes universal gravitation by treating it as a bright idea … A bright idea cannot shape a scientific tradition.” Science is just not that simple and it is not that easy.
. . .
Even if we are not scientists, every day we are challenged to make judgments and decisions about technical matters like vaccinations, financial investments, diet supplements and, of course, global warming. If our discourse on such topics is to be intelligent and productive, we need to dip below the surface and grapple with the complex underlying issues. The myths can seduce one into believing there is an easier path, one that doesn’t require such hard work.
But even beyond issues of science, there is a broader lesson to learn, . . . . We all run into difficult problems in life, and we will be happier and more successful if we appreciate that the answers often aren’t quick, or easy.

For the full commentary, see:
LEONARD MLODINOW. “It Is, in Fact, Rocket Science.” The Wall Street Journal (Sat., MAY 16, 2015): A21.
(Note: ellipsis internal to third quoted paragraph, in original; other ellipses, added.)
(Note: the online version of the commentary was updated on MAY 15, 2015.)

Mlodinow’s book, related to the commentary quoted above, is:
Mlodinow, Leonard. The Upright Thinkers: The Human Journey from Living in Trees to Understanding the Cosmos. New York: Pantheon Books, 2015.

Newly Found, Early Human Species, Respected Their Dead

(p. A1) [A] . . . new hominin species was announced on Thursday, [September 10, 2015] by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language.
In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world.
. . .
The finding, like so many others in science, was the result of pure luck followed by considerable effort.
Two local cavers, Rick Hunter and Steven Tucker, found the narrow entrance to the chamber, measuring no more than seven and a half inches wide. They were skinny enough to squeeze through, and in the light of their headlamps they saw the bones all around them. When they showed the fossil pictures to Pedro Boshoff, a caver who is also a geologist, he alerted Dr. Berger, who organized an investigation.
. . .
(p. A3) Besides introducing a new member of the prehuman family, the discovery suggests that some early hominins intentionally deposited bodies of their dead in a remote and largely inaccessible cave chamber, a behavior previously considered limited to modern humans. Some of the scientists referred to the practice as a ritualized treatment of their dead, but by “ritual” they said they meant a deliberate and repeated practice, not necessarily a kind of religious rite.
. . .
At the news conference in South Africa on Thursday, [September 10, 2015] announcing the findings, Dr. Berger said: “I do believe that the field of paleoanthropology had convinced itself, as much as 15 years ago, that we had found everything, that we were not going to make major discoveries and had this story of our origins figured out. I think many people quit exploring, thought it was safer to conduct science inside a lab or behind a computer.” What the new species Naledi says, Dr. Berger concluded, “is that there is no substitute for exploration.”

For the full story, see:
JOHN NOBLE WILFORD. “Cave Yields Addition to Human Family Tree.”The New York Times (Fri., SEPT. 11, 2015): A1 & A3.
(Note: ellipses, and bracketed word and date, added.)
(Note: the online version of the story has the date SEPT. 10, 2015, and has the title “Homo Naledi, New Species in Human Lineage, Is Found in South African Cave,”)

Fire Cooked Carbohydrates Fed Bigger Brains

(p. D5) Scientists have long recognized that the diets of our ancestors went through a profound shift with the addition of meat. But in the September issue of The Quarterly Review of Biology, researchers argue that another item added to the menu was just as important: carbohydrates, bane of today’s paleo diet enthusiasts. In fact, the scientists propose, by incorporating cooked starches into their diet, our ancestors were able to fuel the evolution of our oversize brains.
. . .
Cooked meat provided increased protein, fat and energy, helping hominins grow and thrive. But Mark G. Thomas, an evolutionary geneticist at University College London, and his colleagues argue that there was another important food sizzling on the ancient hearth: tubers and other starchy plants.
Our bodies convert starch into glucose, the body’s fuel. The process begins as soon as we start chewing: Saliva contains an enzyme called amylase, which begins to break down starchy foods.
Amylase doesn’t work all that well on raw starches, however; it is much more effective on cooked foods. Cooking makes the average potato about 20 times as digestible, Dr. Thomas said: “It’s really profound.”
. . .
Dr. Thomas and his colleagues propose that the invention of fire, not farming, gave rise to the need for more amylase. Once early humans started cooking starchy foods, they needed more amylase to unlock the precious supply of glucose.
Mutations that gave people extra amylase helped them survive, and those mutations spread because of natural selection. That glucose, Dr. Thomas and his colleagues argue, provided the fuel for bigger brains.

For the full story, see:
Carl Zimmer. “MATTER; For Evolving Brains, a ‘Paleo’ Diet of Carbs.” The New York Times (Tues., AUG. 18, 2015): D5.
(Note: ellipses added.)
(Note: the online version of the story has the date AUG. 13, 2015.)

The academic article summarized in the passages above, is:
Hardy, Karen, Jennie Brand-Miller, Katherine D. Brown, Mark G. Thomas, and Les Copeland. “The Importance of Dietary Carbohydrate in Human Evolution.” The Quarterly Review of Biology 90, no. 3 (Sept. 2015): 251-68.

Homo Sapiens Made Eye Contact with Dogs to Dominate Neanderthals

(p. C6) In the space of just a few thousand years, as we spread through the region, we killed off the apex predators: first the Neanderthals and then, over time, cave bears, cave hyenas, lesser scimitar cats, dholes, mammoths and woolly rhinos, among other animals. How did we manage this? According to Ms. Shipman, we enlisted the help of dogs.
. . .
Ms. Shipman devotes the final third of her book to exploring a fascinating range of evidence–genetic, archaeological, anthropological–that provides substantial support for this theory. She never proposes that the alliance of humans and dogs alone led to the extinction of the Neanderthals. In all likelihood, she writes, the mere presence of humans, a competitive new predator in the Eurasian ecosystem, was an important stressor, as were climate change and perhaps even infectious diseases brought by humans from Africa. But the domestication of dogs, she suggests, significantly tipped the balance: “The unprecedented alliance of humans with another top predator (wolf-dogs or a kind of wolf) may have been the final stress that pushed Neanderthals and many other species down the slippery slope toward extinction.”
So how did humans manage to domesticate wolves while their Neanderthal cousins, so similar in so many ways, did not? Here Ms. Shipman gets imaginative. Modern humans, she writes, have recently been shown to be the only extant primates whose irises are surrounded by white scleras–the whites of our eyes. We’re also the only primate to have eyelids that expose much of our scleras. What evolutionary advantage could this have possibly given us? “The white scleras and open eyelids,” she proposes, “make the direction of a person’s gaze highly visible from a distance.” Having white scleras allowed us to communicate subtly at a distance among ourselves and with our new best friend, dogs, a biological advantage that may have made all the difference as we competed for prey with Neanderthals–who, if they were like every other primate we know of today, had dark scleras.
Most animals, including apes and wolves, don’t make eye contact with humans; nor do they gaze at faces for long. Dogs, on the contrary, are excellent gaze-followers, a trait that scientists believe we selectively bred into them during their domestication. Once we had teamed up with dogs, we were unstoppable.

For the full review, see:
TOBY LESTER. “The Slippery Slope to Extinction.” The Wall Street Journal (Sat., March 21, 2015): C5-C6.
(Note: ellipsis added.)
(Note: the online version of the review has the date March 20, 2015.)

The book under review, is:
Shipman, Pat. The Invaders: How Humans and Their Dogs Drove Neanderthals to Extinction. Cambridge, MA: Belknap Press, 2015.

Chimps Are Willing to Delay Gratification in Order to Receive Cooked Food

This is a big deal because cooking food allows us humans to spend a lot less energy digesting our food, which allows a lot more energy to be used by the brain. So one theory is that the cooking technology allowed humans to eventually develop cognitive abilities superior to other primates.

(p. A3) . . . scientists from Harvard and Yale found that chimps have the patience and foresight to resist eating raw food and to place it in a device meant to appear, at least to the chimps, to cook it.
. . .
But they found that chimps would give up a raw slice of sweet potato in the hand for the prospect of a cooked slice of sweet potato a bit later. That kind of foresight and self-control is something any cook who has eaten too much raw cookie dough can admire.
The research grew out of the idea that cooking itself may have driven changes in human evolution, a hypothesis put forth by Richard Wrangham, an anthropologist at Harvard and several colleagues about 15 years ago in an article in Current Anthropology, and more recently in his book, “Catching Fire: How Cooking Made Us Human.”
He argued that cooking may have begun something like two million years ago, even though hard evidence only dates back about one million years. For that to be true, some early ancestors, perhaps not much more advanced than chimps, had to grasp the whole concept of transforming the raw into the cooked.
Felix Warneken at Harvard and Alexandra G. Rosati, who is about to move from Yale to Harvard, both of whom study cognition, wanted to see if chimpanzees, which often serve as stand-ins for human ancestors, had the cognitive foundation that would prepare them to cook.
. . .
Dr. Rosati said the experiments showed not only that chimps had the patience for cooking, but that they had the “minimal causal understanding they would need” to make the leap to cooking.

For the full story, see:
JAMES GORMAN. “Chimpanzees Would Cook if Given Chance, Research Says.” The New York Times (Weds., JUNE 3, 2015): A3.
(Note: ellipses added.)
(Note: the date of the online version of the story is JUNE 2, 2015, and has the title “Chimpanzees Would Cook if Given the Chance, Research Says.”)

The academic article discussed in the passages quoted above, is:
Warneken, Felix, and Alexandra G. Rosati. “Cognitive Capacities for Cooking in Chimpanzees.” Proceedings of the Royal Society of London B: Biological Sciences 282, no. 1809 (June 22, 2015).

Dogs Split from Wolves at Least 27,000 Years Ago

The evidence quoted below might increase the plausibility of the theory that dogs helped give Homo sapiens a survival advantage over Neanderthals.

(p. A8) The ancestors of modern wolves and dogs split into different evolutionary lineages 27,000 to 40,000 years ago, much earlier than some other research has suggested, scientists reported Thursday.

The new finding is based on a bone fragment found on the Taimyr Peninsula in Siberia several years ago. When scientists studied the bone and reconstructed its genome — the first time that had been done for an ancient wolf, or any kind of ancient carnivore — they found it was a new species that lived 35,000 years ago.
Based on the differences between the genome of the new species, called the Taimyr wolf, and the genomes of modern wolves and dogs, the researchers built a family tree that shows wolves and dogs splitting much earlier than the 11,000 to 16,000 years ago that a study in 2014 concluded.

For the full story, see:
JAMES GORMAN. “Dogs Split From Wolves Much Earlier Than Thought.” The New York Times (Fri., MAY 22, 2015): A8.
(Note: ellipses added.)
(Note: the date of the online version of the story is MAY 21, 2015, and has the title “Family Tree of Dogs and Wolves Is Found to Split Earlier Than Thought.”)
(Note: the online version says that the page on the New York edition was A10; my edition is the one that is sent to Omaha.)