As we stand at the forefront of modern civilization, it’s hard to imagine that our most unwelcome companions – bed bugs – have been alongside us for over 60,000 years. A recent study led by researchers from Virginia Tech has revealed that bed bugs may be one of the first human pests, with a history that mirrors the expansion and growth of our species.

The researchers compared the whole genome sequence of two genetically distinct lineages of bed bugs: those associated with humans and those with bats. The findings published in Biology Letters suggest that the human-associated lineage has followed a similar demographic pattern as humans, growing exponentially as cities expanded and populations increased.

“This is an exciting discovery because it highlights the co-evolutionary relationship between humans and bed bugs,” said Lindsay Miles, lead author of the study. “We wanted to look at changes in effective population size, which can tell us what’s been happening in their past.”

The historical and evolutionary symbiotic relationship between humans and bed bugs will inform models that predict the spread of pests and diseases under urban population expansion. By directly tying human global expansion to the emergence and evolution of urban pests like bed bugs, researchers may identify the traits that co-evolved in both humans and pests during urban expansion.

In particular, the study highlights the growth of the human-associated lineage as cities expanded into larger settlements around 12,000 years ago. This corresponds with the early establishment of large human settlements that grew into cities such as Mesopotamia.

“It makes sense because modern humans moved out of caves about 60,000 years ago,” said Warren Booth, the Joseph R. and Mary W. Wilson Urban Entomology Associate Professor. “There were bed bugs living in the caves with these humans, and when they moved out they took a subset of the population with them so there’s less genetic diversity in that human-associated lineage.”

The researchers are now interested in further studying this 245,000 year old lineage split, focusing on the evolutionary alterations of the human-associated lineage compared with the bat-associated lineage that have taken place more recently. In particular, they are looking into what happened in the last 100 to 120 years, when bed bugs were thought to be eradicated but started reappearing and resisting pesticides.

The study is a great example of how researchers can “follow the science” and explore new areas of research, thanks in part to the Joseph R. and Mary W. Wilson endowment that supports Booth’s faculty position.

“It’s a great resource to have,” said Booth. “We are using it for work investigating the evolution of insecticide resistance and species spread using museum specimens collected from 120 years ago to our present-day samples. I’m very lucky to have that freedom to explore.”

The article delves into the fascinating world of elephant brains, highlighting the distinct differences between their Asian and African counterparts. Despite being separated by millions of years of evolution, research has revealed that Asian elephants possess a 20% heavier brain than their larger African relatives. This groundbreaking finding, published in the scientific journal “PNAS Nexus,” sheds light on potential explanations for behavioral differences between the two species, as well as their remarkable youth and long lifespan.

Elephants are renowned for their exceptional social and intelligent nature, yet surprisingly little is known about their brains. A team of international researchers, led by Malav Shah and Michael Brecht from Humboldt-Universität zu Berlin, has analyzed the weight and structure of Asian elephant (Elephas maximus) and African elephant (Loxodonta africana) brains based on dissections of wild and zoo animals, as well as literature data and MRI scans. Their findings show that adult female Asian elephants have significantly heavier brains, weighing an average of 5,300 grams, compared to their African counterparts, which weigh around 4,400 grams.

Moreover, the cerebellum is proportionally heavier in African elephants (22% of total brain weight) than in Asian elephants (19%). The researchers attribute this difference to the more complex motor function of the trunk in African elephants, which can perform diverse movements with their two trunk fingers. This is also reflected in a higher number of neurons in the trunk’s control center in the brain.

The study further reveals that elephant brains grow almost as much as human brains after birth, tripling in weight by adulthood. This remarkable postnatal brain growth exceeds that of all primates, except humans, where the brain at birth weighs only around a fifth of its final weight. The researchers emphasize that this finding is significant for understanding motor skills and social behavior in elephants.

The study’s authors highlight the challenges involved in acquiring elephant brains for research, as extracting them from skulls is a complex veterinary procedure rarely performed. Nevertheless, they were able to analyze 19 brains extracted from deceased zoo animals or wild elephants, including those obtained from dissections of wild elephants that had died. The inclusion of data from an earlier study by another research team further strengthened their analysis.

The implications of these findings are profound, suggesting that the difference in brain weight could explain important behavioral differences between Asian and African elephants. For instance, while both species interact with humans differently, Asian elephants have been partially domesticated over thousands of years and are used as work animals in various cultures and regions. In contrast, there are only a few cases where domestication was even partially successful for African elephants.

The study’s authors conclude that social factors and learning processes could explain the strong brain growth after birth, as elephants live in complex social structures and have an outstanding memory. The experience and accumulated knowledge of adult elephants, especially matriarchs, is central to group behavior in elephants and young animals are closely cared for over a long period of childhood and adolescence.

Ultimately, this research highlights the need for further investigation into the brains of Asian and African elephants and their significance for motor skills and social behavior. As the authors note, there are many unanswered questions in researching these fascinating, intelligent animals and their “control centers.”

Imagine being able to witness a prehistoric creature’s daily life, right down to its stride and movement patterns. This is exactly what a team of researchers from the University of Queensland has achieved through advanced digital modelling techniques.

The Phoenix Trackway, discovered in Sichuan Province, China, is the longest documented set of footprints made by a predator walking on two legs in East Asia. By analyzing these tracks, Dr. Anthony Romilio and his team have reconstructed the journey of this ancient dinosaur, revealing its movements step by step.

“We’ve been able to observe how this dinosaur walked, changed pace, and responded to its environment,” Dr. Romilio explained. “This sequence of 80 consecutive footprints extends for 70 meters, providing a fleeting moment frozen in stone.”

Through digital animation, the research team has brought this ancient creature’s movements back to life. The animation reveals that the dinosaur moved at a steady pace of 5.3 km/h (equivalent to a brisk human walk), before briefly accelerating into a light trot and returning to its regular pace.

The footprints show that this was no aimless wanderer, but an animal moving with purpose in a nearly perfectly straight line. Local folklore once attributed the footprints to a mythical phoenix, but scientific analysis reveals it was an ancient predator similar in size to the feathered Yutyrannus, which lived in northeastern China during the early Cretaceous period.

“Trackways can reveal behavioral information and stories that fossilized bones alone cannot provide,” Dr. Romilio said. “Our entirely digital approach allows us to capture, interpret, and preserve all the measurements and calculations of fossil track sites on computer, providing a glimpse into the dynamic life of an ancient creature.”

The study, co-authored by Dr. Lida Xing from China University of Geosciences, Beijing, is published in Geosciences. This groundbreaking research highlights the importance of digital reconstruction in understanding prehistoric life and the potential for new discoveries through advanced modelling techniques.