The fascinating world of animal evolution has taken an intriguing turn with the discovery of similarities between two species that were previously thought to be quite different: pug dogs and Persian cats. Scientists from Cornell University and Washington University have uncovered evidence of “convergence,” a phenomenon where unrelated animals or plants develop similar characteristics under similar environmental conditions.

The study reveals that, due to intensive breeding, certain breeds within these two domesticated species have converged to such an extreme that they are more similar to each other than they are to most members of their own species or their ancestors. This remarkable convergence is not only observed within the pug and Persian breeds but also between them.

Researchers measured the skulls of brachycephalic dogs and cats, finding strikingly similar overlap between these breeds from two different species. “Persian cats and pug and Pekingese dogs all have skull shapes that are very similar to each other,” said Abby Drake, senior lecturer at Cornell University. “Their muzzles and palettes are tilted up in the same way.”

This convergence has occurred multiple times within each species. In dogs, it is seen in bulldog breeds, as well as Asian dog breeds such as Pekingese and Shih Tzu. In cats, the same traits can be observed in Persian, Himalayan, and Burmese breeds.

The study also highlights the rapid evolution of domesticated species, which can offer insights into evolutionary processes. “When convergence occurs through natural selection,” said Drake, “it is usually a sign of a successful trait.” However, the extreme breeding practices that led to this convergence have resulted in health issues for brachycephalic breeds.

The researchers collected three-dimensional measurements of skull morphology from CT scans of domestic cats, dogs, wildcats, wolves, and other species within the Canidae and Felidae families. These measurements revealed a remarkable diversity of both cats and dogs, with dog diversity being even more extreme.

The study concludes that artificial selection has led to a large evolutionary variation within these species, which would not be seen in natural evolution over millions of years. Unfortunately, this rapid evolution comes at a cost, as brachycephalic breeds are susceptible to breathing, eating, and birthing issues and would not survive in the wild.

The findings of this study provide valuable insights into the evolutionary processes that occur when humans intervene with breeding practices. They also highlight the importance of considering the health implications of such practices for the animals themselves.

The discovery of a skeleton in a Roman cemetery in York has provided the first archaeological evidence of gladiatorial combat between humans and lions. The bite marks found on the skeleton confirm that it was a gladiator who fought against a lion, providing a rare glimpse into the lives of these ancient fighters.

Malin Holst, a lecturer in Osteoarchaeology at the University of York, led the research team that made this groundbreaking discovery. She explained that the bite marks were likely made by a lion, which confirms that the skeletons buried at the cemetery were gladiators rather than soldiers or slaves.

“This is the final piece of evidence from work that began in 2004,” said Holst. “We have been excavating and analyzing human remains from the Roman cemetery on Driffield Terrace, and this discovery provides a unique insight into the lives of these ancient fighters.”

The skeleton was buried with two others, and overlaid with horse bones. In life, it appears to have had some issues with its spine that may have been caused by overloading to its back, inflammation of its lung and thigh, as well as malnutrition as a child, which he recovered from.

The lion bite wound — confirmed by comparing it to sample bites from a lion at a zoo — was not healed and is therefore likely to have been his cause of death. It is believed that the individual was decapitated after death, which appears to have been a ritual for some individuals in the Roman period, although the reasons for this remain unclear.

Analysis of the skeleton points towards this being a Bestarius, a gladiator role undertaken by volunteers or slaves.

The discovery has significant implications for our understanding of Roman entertainment culture. It was previously thought that gladiatorial combat only took place in major cities like Rome, but this find suggests that it was also practiced in smaller cities and towns throughout the empire.

“We often have a mental image of these combats occurring at the grand surroundings of the Colosseum in Rome,” said Holst, “but these latest findings show that these sporting events had a far reach, well beyond the centre of core Roman territories.”

York appears to have held gladiator arena events until as late as the fourth century AD. The presence of distinguished Roman leaders in York would have meant they required a lavish social life, and it is not surprising to see evidence of gladiator events, as well as such an extensive burial site for them.

The research team’s findings were published in the Journal of Science and Medical Research PLoS One, and are a collaboration between the University of York, Maynooth University, Cranfield University, Durham University, King’s College London, York Archaeology, and York Osteoarchaeology Ltd.

Feral cats have long been suspected of being a major contributor to the decline and extinction of native animals in Australia. However, a recent study published in the Australian Mammalogy journal has provided conclusive evidence that feral cats are indeed the primary predators responsible for the deaths of reintroduced native animals at two conservation sites in South Australia.

Researchers from UNSW Sydney and the University of Adelaide used DNA technology to identify feral cats as the culprits in killing 74 out of 389 released animals, with a staggering 96% of these confirmed by DNA analysis. This finding fits in with previous research that suggests feral cats have killed more native animals than any other feral predator in Australia.

The study’s lead author, Professor Katherine Moseby, notes that determining the cause of death of native animals and attributing it to the right predator has always been a challenge. “In past releases, we’d be radio tracking animals after release, and if we found dead animals, it would be difficult to determine what caused their death,” she says.

The researchers used DNA swabs from carcasses and compared them with evidence in the field, such as animal spoor, carcass remains, or bite marks on collars. They found that field evidence was not a reliable indicator of predation by feral cats, and that DNA and necropsy were needed to confirm cat predation.

At one site, researchers released 148 brush-tailed possums and 110 western quolls between 2014 and 2016, while at the other site, they released 42 greater bilbies and 89 bettongs in 2017. Unfortunately, three out of the four species released still managed to survive in reduced numbers, with the bettongs being no match for feral cats.

The study’s findings have significant implications for conservation efforts, highlighting that there are more cat killings than previously thought. As Professor Moseby notes, “Until we develop genetic tools or other broadscale methods targeted at feral cats, we can only rely on intensely managing them as best we can.”

The researchers hope that their research will encourage more conservationists to use DNA and necropsy to identify the cause of death of animals in wildlife reintroductions, and to increase cat control even if no obvious evidence of cat predation is present.