evolution
October 26, 2023
Fruit, nectar, bugs and blood: How bat teeth and jaws evolved for a diverse dinnertime
There are more than 200 species of noctilionoid bats, mostly in the American tropics. And despite being close relatives, their jaws evolved in wildly divergent shapes and sizes to exploit different food sources. A paper published Aug. 22 in Nature Communications shows those adaptations include dramatic, but also consistent, modifications to tooth number, size, shape and position. For example, bats with short snouts lack certain teeth, presumably due to a lack of space. Species with longer jaws have room for more teeth — and, like humans, their total tooth complement is closer to what the ancestor of placental mammals had.
April 13, 2023
Africa’s grassy habitats emerged 10+ million years earlier than previously thought
A pair of studies published April 14 in the journal Science paint a new picture about apes, ancient Africa and the origins of humans. Many scientists had once hypothesized that the first apes to evolve in Africa more than 20 million years ago ate primarily fruit and lived within the thick, closed canopy of a nearly continent-wide forest ecosystem. Instead, the new research indicates that early apes ate a leafy diet in a more arid ecosystem of varyingly open woodlands with abundant grasses.
September 7, 2022
These female hummingbirds evolved to look like males — apparently to evade aggression
1 in 5 adult female white-necked jacobin hummingbirds look like males. New research from the University of Washington shows that this is a rare case of “deceptive mimicry” within a species: Females with male-like plumage are trying to pass themselves off as males, and as a result receive a benefit in the form of reduced aggression from males.
July 25, 2022
New study challenges old views on what’s ‘primitive’ in mammalian reproduction
Which group of mammals has the more “primitive” reproductive strategy — marsupials, with their short gestation periods, or humans and other placental mammals, which have long gestation periods? For decades, biologists viewed marsupial reproduction as “more primitive.” But University of Washington scientists have discovered that a third group of mammals, the long-extinct multituberculates, had a long gestation period like placental mammals. Since multituberculates split off from the rest of the mammalian lineage before placentals and marsupials had even evolved, these findings question the view that marsupials were “less advanced” than their placental cousins.
October 27, 2021
Fossil dental exams reveal how tusks first evolved
Many animals have tusks, from elephants to walruses to hyraxes. But one thing tusked animals have in common is that they’re all mammals — no known fish, reptiles or birds have them. But that was not always the case. In a study published Oct. 27 in the Proceedings of the Royal Society B, a team of paleontologists at Harvard University, the Field Museum, the University of Washington and Idaho State University traced the first tusks back to dicynodonts — ancient mammal relatives that lived before the dinosaurs.
September 21, 2021
UW, Burke researchers discover four dinosaurs in Montana: Fieldwork pieces together life at the end of ‘Dinosaur Era’
A team of paleontologists from the University of Washington and its Burke Museum of Natural History and Culture excavated four dinosaurs in northeastern Montana this summer. The four dinosaur fossils are: the ilium — or hip bones — of an ostrich-sized theropod, the group of meat-eating, two-legged dinosaurs that includes Tyrannosaurus rex and raptors; the hips and legs of a duck-billed dinosaur; a pelvis, toe claw and limbs from another theropod that could be a rare ostrich-mimic Anzu, or possibly a new species; and a Triceratops specimen consisting of its skull and other fossilized bones.
August 11, 2021
‘More pepper, please’: New study analyzes role of scent compounds in the coevolution of bats and pepper plants
A study published Aug. 11 in the Proceedings of the Royal Society B by researchers at the University of Washington and Stony Brook University reports on how bats and pepper plants in Central America have coevolved to help each other survive.
August 5, 2021
Now how did that get up there? New study sheds light on development and evolution of dolphin, whale blowholes
New research by scientists at the University of Washington and Duke University is shedding light on how the nasal passage of dolphins and whales shifts during embryonic development from emerging at the tip of the snout to emerging at the top of the head as a blowhole. The findings, published July 19 in the Journal of Anatomy, are an integrative model for this developmental transition for cetaceans.
February 24, 2021
Scientists describe earliest primate fossils
A new study published Feb. 24 in the journal Royal Society Open Science documents the earliest-known fossil evidence of primates. These creatures lived less than 150,000 years after the Cretaceous-Paleogene mass extinction event that killed off non-avian dinosaurs and saw the rise of mammals.
November 2, 2020
No social distancing in the Cretaceous: New study finds earliest evidence for mammal social behavior
A new study led by paleontologists at the University of Washington indicates that the earliest evidence of mammal social behavior goes back to the Age of Dinosaurs. A multituberculate that lived 75.5 million years ago, Filikomys primaevus engaged in multi-generational, group-nesting and burrowing behavior, and possibly lived in colonies.
August 27, 2020
Frequently asked questions: torpor in Antarctic Lystrosaurus
This FAQ discusses evidence for a hibernation-like condition in Lystrosaurus, a mammal relative that lived in the Antarctic portion of Pangea about 250 million years ago. This discovery was enabled by high-resolution of incremental growth marks preserved in the tusks of Lystrosaurus.
Weathering the tough times: Fossil evidence of ‘hibernation-like’ state in 250-million-year-old Antarctic animal
University of Washington scientists report evidence of a hibernation-like state in Lystrosaurus, an animal that lived in Antarctica during the Early Triassic, some 250 million years ago. The fossils are the oldest evidence of a hibernation-like state in a vertebrate, and indicate that torpor — a general term for hibernation and similar states in which animals temporarily lower their metabolic rate to get through a tough season — arose in vertebrates even before mammals and dinosaurs evolved.
April 27, 2020
Bacteria that are persistently resistant to one antibiotic are ‘primed’ to become multidrug-resistant bugs
Researchers at the University of Washington and the University of Idaho report that, for a bacterial pathogen already resistant to an antibiotic, prolonged exposure to that antibiotic not only boosted its ability to retain its resistance gene, but also made the pathogen more readily pick up and maintain resistance to a second antibiotic and become a dangerous, multidrug-resistant strain.
December 30, 2019
Life could have emerged from lakes with high phosphorus
Life as we know it requires phosphorus, which is scarce. So, how did a lifeless environment on the early Earth supply this key ingredient? A new UW study, published Dec. 30 in the Proceedings of the National Academy of Sciences, finds an answer to this problem in certain types of carbonate-rich lakes.
October 24, 2019
New fossil trove documents recovery of life on Earth after dinosaur-killing asteroid impact
Scientists have discovered an extraordinary collection of fossils that reveal in detail how life recovered after a catastrophic event: the asteroid impact that wiped out the dinosaurs 66 million years ago at the end of the Cretaceous Period.
October 17, 2019
Old friends and new enemies: How evolutionary history can predict insect invader impacts
A team led by the University of Washington has developed a way to help foresters predict which nonnative insect invasions will be problematic, and help managers decide where to allocate resources to avoid widespread tree death.
August 12, 2019
First cells on ancient Earth may have emerged because building blocks of proteins stabilized membranes
Scientists have discovered that the building blocks of proteins can stabilize cell membranes. This finding may explain how the first cells emerged from the primordial soup billions of years ago: The protein building blocks could have stabilized cell membranes against salt and ions that were present in ancient oceans. In addition, membranes may have been a site for these precursor molecules to co-localize, a potential mechanism to explain what brought together the ingredients for life.
July 1, 2019
Study shows that management and evolution give hope to coral reefs facing the effects of climate change
A new study released July 1 in Nature Climate Change gives hope for coral reefs. Launched by the nonprofit Coral Reef Alliance, with lead and senior authors at the University of Washington, the study is one of the first to demonstrate that management that takes evolution and adaptation into account can help rescue coral reefs from the effects of climate change.
June 20, 2019
Mammals and their relatives thrived, diversified during so-called ‘Age of Dinosaurs,’ researchers show
Old myths state that, during the time of the dinosaurs, mammals and their relatives were small and primitive. But new research shows that, during the time of the dinosaurs, mammals and their relatives actually underwent two large ecological radiations, diversifying into climbing, gliding and burrowing forms with a variety of diets.
May 2, 2019
Bats evolved diverse skull shapes due to echolocation, diet
In a paper published May 2 in Nature Communications, a University of Washington team reports that two major forces have shaped bat skulls over their evolutionary history — echolocation and diet — generating a huge diversity of skull shapes across 1,300 bat species today.
April 30, 2019
Flowering plants, new teeth and no dinosaurs: New study sheds light on the rise of mammals
A new study published April 30 in the Proceedings of the National Academy of Sciences identified three factors critical in the rise of mammal communities since they first emerged during the Age of Dinosaurs: the rise of flowering plants; the evolution of tribosphenic molars in mammals; and the extinction of non-avian dinosaurs, which reduced competition between mammals and other vertebrates in terrestrial ecosystems.
November 19, 2018
UW’s Marina Alberti to lead new NSF-funded research network to study impact of cities on Earth’s evolutionary dynamics
Here in what is called the Anthropocene era, humans and our urban environments appear to be driving accelerated evolutionary change in plants, animals, fungi, viruses and more — changes that could affect key ecosystem functions and thus human well-being. These interactions between evolution and ecology are called “eco-evolutionary feedback.” The National Science Foundation has awarded…
March 2, 2018
Two species of ravens nevermore? New research finds evidence of ‘speciation reversal’
A new study almost 20 years in the making provides some of the strongest evidence yet of the “speciation reversal” phenomenon in two lineages of common ravens.
March 14, 2017
In times of plenty, penguin parents keep feeding their grown offspring
A research team led by University of Washington biology professor Dee Boersma reports that fully grown Galapagos penguins who have fledged — or left the nest — continue to beg their parents for food. And sometimes, probably when the bounty of the sea is plentiful, parents oblige and feed their adult offspring.
January 24, 2017
Prized fossil find — the oldest, most complete iguanian in the Americas — illuminates the lives of lizards in the Age of Dinosaurs
Paleontologists picking through a bounty of fossils from Montana have discovered something unexpected — a new species of lizard from the late dinosaur era, whose closest relatives roamed in faraway Asia.
December 8, 2016
New study traces the marsupial origins in N. America, finds mammals during Age of Dinosaurs packed a powerful bite
A new study by paleontologists at the Burke Museum of Natural History & Culture and the University of Washington describes an early marsupial relative called Didelphodon vorax that lived alongside dinosaurs and had, pound-for-pound, the strongest bite force of any mammal ever recorded.
Fossilized evidence of a tumor in a 255-million-year-old mammal forerunner
University of Washington paleontologists have discovered a benign tumor made up of miniature, tooth-like structures embedded in the jaw of an extinct ‘mammal-like’ gorgonopsian. Known as a compound odontoma, this type of tumor is common to mammals today. But this animal lived 255 million years ago, before mammals even existed.
September 23, 2016
How natural selection acted on one penguin species over the past quarter century
University of Washington biologist Dee Boersma and her colleagues combed through 28 years’ worth of data on Magellanic penguins to search for signs that natural selection — one of the main drivers of evolution — may be acting on certain penguin traits. As they report in a paper published Sept. 21 in The Auk: Ornithological Advances, selection is indeed at work on the penguins at the Punta Tombo breeding site in Argentina.
August 18, 2016
Paleontologists with the UW’s Burke Museum discover major T. rex fossil
Paleontologists with the Burke Museum of Natural History and Culture and the UW have discovered a Tyrannosaurus rex, including a very complete skull. The find, which paleontologists estimate to be about 20 percent of the animal, includes vertebrae, ribs, hips and lower jaw bones.
May 11, 2016
Skull specializations allow bats to feast on their fellow vertebrates
Over their 52-million-year history, a few bats have evolved a taste for their fellow vertebrates. Now biologists at the University of Washington and the Burke Museum of History and Culture are shedding light on how these so-called “carnivorous bats” adapted to the daunting task of chowing down their backboned prey.
September 10, 2015
UW scientists will continue studies of evolution ‘in real time’ with five-year grant renewal
Faculty members from several departments at the University of Washington will share $2.25 million in research funds from the National Science Foundation to study and apply the principles of evolution “in real time.” Their studies are a part of the BEACON Center for the Study of Evolution in Action. Founded in 2010, this NSF science…
February 18, 2015
Fearless birds and shrinking salmon: Is urbanization pushing Earth’s evolution to a tipping point?
We’ve long known that humans and our cities affect the ecosystem and even drive some evolutionary change. What’s new is that these evolutionary changes are happening more quickly than previously thought, and have potential impacts not in the distant future — but now.
January 29, 2014
Neanderthal lineages excavated from modern human genomes
A fossil-free method of sequencing archaic DNA may provide insight into human evolution.
July 3, 2013
Great ape genetic diversity catalog frames primate evolution and future conservation
A model of great ape history during the past 15 million years has been fashioned through the study of genetic variation in a large panel of humans, chimpanzees, gorillas and orangutans.
March 29, 2013
Head-on collisions between DNA-code reading machineries accelerate gene evolution
Bacteria speed up their evolution by positioning specific genes along the route of expected traffic jams in DNA encoding. Collisions can result in mutations.
March 4, 2013
‘True grit’ erodes assumptions about evolution
New work in Argentina where scientists had previously thought Earth’s first grasslands emerged 38 million years ago, shows the area at the time covered with tropical forests rich with palms, bamboos and gingers. Grit and volcanic ash in those forests could have caused the evolution of teeth in horse-like animals that scientists mistakenly thought were adaptations in response to emerging grasslands.
February 19, 2013
Mutant champions save imperiled species from almost-certain extinction
Species facing widespread and rapid environmental changes can sometimes evolve quickly enough to dodge the extinction bullet. UW scientists consider the genetic underpinnings of such evolutionary rescue.
December 26, 2012
Piranha kin wielded dental weaponry even T. rex would have admired — with video
Taking into consideration size, an ancient relative of piranhas weighing about 20 pounds delivered a bite with more force than prehistoric whale-eating sharks or – even – Tyrannosaurus rex.
December 6, 2012
Moths wired two ways to take advantage of floral potluck
Moths are able to enjoy a pollinator’s buffet of flowers because of two distinct “channels” in their brains, scientists have discovered.
September 4, 2012
Gardener’s delight offers glimpse into the evolution of flowering plants
Double flowers – though beautiful – are mutants. UW biologists have found the class of genes responsible in a plant lineage more ancient than the one previously studied, offering a glimpse even further back into the evolutionary development of flowers.
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