Commonly used police diversity training unlikely to change officers’ behavior, study finds

Peer-Reviewed Publication

WASHINGTON UNIVERSITY IN ST. LOUIS    

Tyre Nichols, a 29-year-old Black man who died after a confrontation with police during a traffic stop earlier this month in Memphis, has become the latest face in a racial justice and police reform movement fueled by a string of similar cases in which Black men have died from injuries sustained while being taken into custody.

While these cases have spurred calls for greater law enforcement investment in diversity training, new research from Washington University in St. Louis suggests that the day-long implicit bias-oriented training programs now common in most U.S. police departments are unlikely to reduce racial inequity in policing.

“Our findings suggest that diversity training as it is currently practiced is unlikely to change police behavior,” said study lead author Calvin Lai, assistant professor of psychological and brain sciences in Arts & Sciences at Washington University in St. Louis.

“Officers who took the training were more knowledgeable about bias and more motivated to address bias at work,” Lai said.” However, these effects were fleeting and appear to have little influence on actual policing behaviors just one month after the training session.”

Published Feb. 3 in the journal Psychological Science, the study evaluates the experiences of 3,764 police officers from departments across the nation who participated in one-day bias training sessions provided by the non-profit Anti-Defamation League.

The interactive workshops, which emphasize discussion and active learning over lecturing, were designed to help officers understand how their worldview is shaped by their identity and culture and to appreciate how these biases may affect their behavior.

Lai’s evaluation of the program, which covered 251 training sessions held between July 2019 and January 2022, is based on police officers’ self-reported responses to surveys conducted before training, immediately after training and one month later.

When officers were asked to describe their thoughts about the training, many reported that it was surprising and insightful. For instance, one officer wrote “it has opened my eyes to the bias we all have as human beings” and another said, “I really liked the course because it opened my eyes to implicit biases I never knew I had.”

Officers participating in the study had an average of 15 years of service and most had been with their departments for more than five years. Most were below the rank of sergeant, 77% were male and 79% held a bachelor’s degree or higher. Among those who reported their race, 47% were white, 20% were Black, 27% were Hispanic/Latino and 2% were Asian.

The final section of the training program focused on building skills to manage bias in policing. These strategies included mindfulness, such as intentionally bringing bias awareness to the present moment, and other interventions designed to help officers avoid perceptions based on negative stereotypes and see people as unique individuals with their own points of view.

While the training produced an immediate and long-lasting understanding of bias, it delivered only a temporary bump in concerns about bias and in the motivation to use strategies to limit bias in law enforcement interactions.

“Educating about implicit bias was effective for durably raising awareness about the existence of subtle or implicit biases, but little else,” Lai said. “Our study indicates that the current generation of diversity training programs are effective at changing minds but less consistent at changing behavior.”

Lai, who is currently working with the U.S. Department of Justice’s Office of Community Oriented Policing Services to develop a new managing bias training course for law enforcement agencies, says it’s important to manage expectations about what can be accomplished in a single, standalone training session.

His study documents shortcomings in the Anti-Defamation League’s Managing Bias program, which he considers to be one of the nation’s best available diversity training programs. The program is research-based, comes with an 80-page instruction manual and is delivered by two-person teams of highly trained facilitators.

“The day-long training is more intensive than other diversity trainings, which are often only one to three hours,” Lai said. “And yet, we found little evidence for long-term efficacy.”

Lai’s research suggests that police departments can boost the effectiveness of diversity training by showing a genuine, long-term commitment to program goals and ensuring that classroom bias training lessons are embedded with other organizational initiatives, reinforced by police managers and evaluated as a part of job performance.

“Changing minds is hard, creating social change is difficult, but that doesn’t mean it isn’t worth doing,” Lai said. “We have to eliminate this all-or-none thinking about the effectiveness of implicit bias training and focus on specific changes that police departments can implement to make a real difference in outcomes.”

This study was supported by grants from the Anti-Defamation League and the Russell Sage Foundation. Co-authors include Jacklyn Lisnek, a former lab manager in Lai’s lab now pursuing a doctoral degree in social psychology at the University of Virginia.

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JOURNAL

Psychological Science

DOI

10.1177/0956797622115061 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The impact of implicit-bias-oriented diversity training on police officers’ beliefs, motivations, and actions

ARTICLE PUBLICATION DATE

3-Feb-2023

Preference for naturally talented over hard workers emerges in childhood, HKUST researchers find

Peer-Reviewed Publication

HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY

 

IMAGE: CHILDREN THINK MORE HIGHLY OF THE NATURALLY TALENTED OVER HARD WORKERS, ACCORDING TO A RESEARCH BY HKUST. view more 

CREDIT: HKUST

 Researchers at the Hong Kong University of Science and Technology (HKUST) have found that children think more highly of the naturally talented over hard workers, a preference that they carry into adulthood.

    That is the case even in China, a culture that places effort above natural talent as people perceive the naturally talented as being more competent than those who work hard, according to the study.

    Although children’s preference for naturals also generalizes to the perception of their friendliness and a willingness to interact with them, Chinese adults do not prefer naturals over hard workers except when considering competence, the study found.

    The study was led by PhD candidate Mary Shaocong MA under the supervision of Prof. Eva E. CHEN, Adjunct Associate Professor of the Division of Social Science, HKUST, who collaborated with Prof. Chia-Jung TSAY, Associate Professor at University College London and University of Wisconsin-Madison.

    “Given the value we place on achievement, how we assess and perceive achievements matters. Our research implies an early-emerging hidden bias toward individuals with different achievement trajectories. Although natural talent and hard work are both considered essential ways to achieve, our findings suggest that people actually prefer talented naturals over hard workers, and this naturalness preference exists in childhood and endures into adulthood,” says MA, who is currently also a Visiting Scholar at Harvard University.

    “The bias can consequently impact children’s interactions with peers perceived as talented or hardworking as it can lead them to interact more with the naturally talented over hard workers. The apparent decrease of this preference with age also implies it may be more malleable than previously thought,” she says.

    The naturalness bias refers to the implicit preference individuals have for naturals, who display inborn talent, over strivers, who expend effort to attain equal achievement.

    For instance, in past studies led by Prof. Tsay, when presented with the same musical performance, participants judged the performance and perceived the performer's potential for success more highly if the musician was portrayed as a talented natural rather than as a hardworking striver. These patterns were also found in evaluations of entrepreneurs.

    Although past research suggested a general preference for people who find success through talent, little was known about whether the naturalness preference is present at an early age.

    In the present research, the team conducted two studies to examine the preference among approximately 350 adults and 300 children, specifically those aged between 5 and 6 years, in Mainland China, where traditional philosophies and social norms encourage hard work, the study writes.

    In Study 1, participants were randomly assigned to two groups: In one group, participants heard a story about someone who had attained high skills in making friends from natural talent; while in the other group, participants heard the same story, except the person’s skill was attained through hard work. They then rated the person’s characteristics reflecting their competence (e.g., intelligence) and character warmth (e.g., friendliness). This design was intended to examine if participants perceived different levels of competence and warmth in naturals versus strivers, and whether any such perceptions differed by age.

    In Study 2, participants were shown a natural and a striver. Then they indicated their behavioral preferences in a series of tasks that aimed to examine with whom participants preferred to interact more and to whom they preferred to allocate more resources.

    The findings have been published recently in a top international journal in developmental psychology, Child Development.

    “Our findings imply that parents and educators should guide children to properly view their own talent and effort, and to understand that both talent and effort can contribute to an equal level of achievement. They should also guide their children to appreciate the competence and achievements of their peers who have achieved through different trajectories to promote an inclusive learning environment,” says Ma.

    Policymakers in education may also work to reduce the impact of the naturalness preference by fairly allocating resources to learners who exhibit different levels of innate abilities, she suggests.

In Study 1, children perceive naturals as more competent and warmer than strivers. Adults perceive naturals as more competent, but not warmer, than strivers.

In Study 2, children prefer learning from and socializing with natural over strivers. Adults do not prefer learning from either natural or strivers, but prefer socializing with strivers over naturals.

CREDIT

HKUST

JOURNAL

Child Development

ARTICLE TITLE

Preference for talented naturals over hard workers emerges in childhood and shapes behavior

Playtime is purr-fect for your cat’s welfare

Peer-Reviewed Publication

UNIVERSITY OF ADELAIDE

Play is often considered an indicator and promotor of animal welfare. Playing with your cat may also nurture closer cat-human bonds. In a new study, scientists have investigated these links by applying in-depth empirical methods to analyse data gathered from around the world.

Researchers in the University of Adelaide from the School of Animal and Veterinary Science created an online survey in consultation with veterinarians, animal behaviourists, and cat guardians, to investigate play-related factors associated with welfare in cats. The outcome measures include: cat quality of life, cat-guardian relationship quality, problem behaviour prevalence, and behavioural changes.

“Our survey results, based on responses from 591 cat guardians from 55 countries, indicated greater cat playfulness and more types of games played were significantly associated with better cat quality of life,” said the University of Adelaide’s Julia Henning, a PhD Candidate, who led the study.

“Also, longer amounts of daily play, greater number of games, both cat and guardian initiating play, and heightened guardian playfulness were also associated with better quality cat-guardian relationships.”

When it comes to indoor/outdoor cats, exclusively indoor housing was significantly associated with both increased cat quality of life and cat-guardian relationships compared to cats with outdoor access.

“Behavioural changes that indicated stress, frustration, or unease were reported when play was absent. Therefore, we can conclude play may be a very important factor in assessing and maintaining cat welfare,” Ms Henning said.

The team recently published their findings in the Animal Welfare journal.

“Play has long been considered beneficial to cats. Pre-existing research links play to cats’ long-term neurological, physiological, behavioural, and emotional skills, as well as fitness and general good health.”

Associate Professor Susan Hazel, Senior Lecturer at the University of Adelaide who also worked on the study, said: “While our research is an important contribution to knowledge around cat welfare, self-reporting surveys have limitations.”

“Cat lovers’ answers may be prone to respondent and recall bias and limited in their ability to assess behaviour.”

“Participants who dedicated their time and effort on a voluntary basis are more invested in their cat’s care than the average cat guardian. Therefore, responses may not be an accurate representation of the general population.”

“Ultimately, we recommend more research is needed. Further investigations could solve exactly how much play and what kind is best suited to achieving improved cat welfare. That would be the cat’s meow.”

The research team included Dr Torben Nielsen and Eduardo Fernandez, also from the School of Animal and Veterinary Science. The research was funded by the University of Adelaide.

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JOURNAL

Animal Welfare

DOI

10.1017/awf.2023.2 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Cats just want to have fun: Associations between play and welfare in domestic cats

New study has important implications for survival of the critically endangered Kākāpō parrot

Peer-Reviewed Publication

PEERJ

A new study published in PeerJ Life & Environment has provided crucial insights into the factors that affect the fertility of the critically endangered kākāpō, a flightless parrot species native to New Zealand. The results of the study have important implications for conservation management efforts aimed at improving the slow population growth of this species, and highlights the need for a balanced approach to conservation management, taking into account both the short-term benefits and potential long-term negative impacts of hand-rearing and other management strategies.

The findings have immediate applications in kākāpō conservation management:

1. Hand-rearing should be limited as much as possible for males; a reversal from previous strategies in which retaining female chicks in nests was prioritised.
2. Population densities should be maximised so that there are sufficient males at leks to ensure adequate mate choice for females, but such that the female:male sex ratio is kept as high as the habitat can support.
3. Artificial insemination should also be continued, to ensure sufficient sperm competition and increase founder representation.

Low productivity limits population recovery of the kākāpō (Strigops habroptilus), with infrequent breeding, high infertility and low hatching success hampering conservation efforts.  Kākāpō breeding occurs irregularly, synchronised with the mass-fruiting (masting) of certain tree species, particularly the rimu tree (Dacrydium cupressinum), which only occurs every 2-4 years. 

Conservation strategies for wild-living threatened species such as the kākāpō rely on improving survival and productivity to increase population growth. Methods such as habitat restoration and predator control are used to enhance survival, but it is often problems with reproductive output which most limit recovery. Hand-rearing, in which animals are raised in captivity by humans, is often used in threatened species conservation programmes, primarily to increase productivity by improving survival during development to maturity.

The study used Bayesian mixed models to examine the relationship between hand-rearing, other environmental factors, and clutch fertility in the kākāpō. 

The results study suggests that some aspects of conservation management have inadvertently affected kākāpō productivity by reducing clutch fertility. The management intervention of  hand-rearing, while undoubtedly increasing chick survival, has decreased clutch fertility. The sex difference in this effect indicates that hand-rearing affects copulation behaviour in males more than females, in accordance with imprinting behaviours found in hand-reared male but not female kākāpō.

The research also found that female copulation behaviour - including polyandry and repeated copulations - is likely driven by high levels of sperm competition in kākāpō to improve the likelihood of fertilisation.

The findings of this study indicate the critical importance of collecting detailed longitudinal data, and investigating similar impacts of hand-rearing and sex ratios in other threatened bird species.

About the kākāpō

Up to 64 cm (25 in) in length, these flightless birds have finely blotched yellow-green plumage, a distinct facial disc, owl-style forward-facing eyes with surrounding discs of specially-textured feathers, a large grey beak, short legs, large blue feet, and relatively short wings and tail: a combination of traits making it unique among parrots. It is the world's only flightless parrot, the world's heaviest parrot, and also is nocturnal, herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate, and does not have male parental care. It is the only parrot to have a polygynous lek breeding system. It is also possibly one of the world's longest-living birds, with a reported lifespan of up to 100 years.

The kākāpō is critically-endangered; the total known adult population is 249 living individuals, all of which are named and tagged, confined to four small islands off the coast of New Zealand that have been cleared of predators.

The name kākāpō is Maori, and translates as 'night parrot'. 

Listen to the kākāpō’s calls https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/kakapo/

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JOURNAL

PeerJ

DOI

10.7717/peerj.14675 

ARTICLE TITLE

Hidden impacts of conservation management on fertility of the critically endangered kākāpō

ARTICLE PUBLICATION DATE

3-Feb-2023

Rates of hatching failure in birds almost twice as high as previously estimated

Hatching failure rates in birds are almost twice as high as experts previously estimated, according to the largest ever study of its kind.

Peer-Reviewed Publication

UNIVERSITY OF SHEFFIELD

Rates of hatching failure in birds almost twice as high as previously estimated

• New study from the University of Sheffield, IoZ, and UCL found more than one in six bird eggs fail to hatch

• Hatching failure increases as species decline, so the new research could be used to predict what species are most at risk of extinction
• Findings reveal that hatching failure is a much bigger problem for captive threatened species, with almost half (43 per cent) of their eggs failing to hatch
• The work provides evidence that conservation managers can use to support their decision making, creating the best possible outcomes for threatened bird species recovery
• More than 240 bird species were examined in the largest and most comprehensive analysis of the drivers of hatching failure in birds

Hatching failure rates in birds are almost twice as high as experts previously estimated, according to the largest ever study of its kind.

The new report highlights how conservationists can best support the recovery of threatened bird species, as it outlines how different conservation practices may affect hatching rates.

Researchers from the University of Sheffield, Institute of Zoology, and University College London (UCL) looked at 241 bird species across 231 previous studies to examine hatching failure. They found that nearly 17 per cent of bird eggs fail to hatch - almost double the figure reported 40 years ago of just over nine per cent.

The findings suggest that more than one in six bird eggs fail to hatch, and the numbers are even more stark in endangered species - almost half (43 per cent) of eggs from threatened species that are bred in captivity are unsuccessful in hatching, which presents a major barrier to their recovery as a species.

Dr Nicola Hemmings, Co-Author from the University of Sheffield’s School of Biosciences, said: “Around 13 per cent of bird species globally are currently threatened with extinction, and things are getting worse instead of better. Species on the verge of extinction have much higher levels of hatching failure compared to non-threatened species, and breeding birds in captivity appears to be having a negative impact.

“There are important considerations that we need to make - does the benefit of captivity and other interventions outweigh the reduced reproduction of these species? For many species, these practices are absolutely vital for species survival,, so we need to carefully weigh up the pros and cons of different approaches to ensure that we are doing everything that we can to protect birds from extinction.”

The findings outline four different conservation practices that were associated with lower hatching rates:

• Birds kept in captivity compared to being in the wild or free living
• Eggs hatched in artificial incubators as opposed to natural nests with parental incubation
• Birds being fed supplementary food
• Birds using artificial nest boxes/sites instead of natural nest sites

However, despite any potential negative impacts these have on hatching, they may still be important to birds’ reproduction and survival - for example, the eggs of some ground-nesting birds are at such high risk of predation that leaving them in wild nests would result in all of the eggs being destroyed.

As a result, there are pros and cons of each conservation technique, and the researchers hope that these findings will act as a framework for conservationists to assess what the best strategy is for each species of bird, to make sure that they have the best hatching chance while also keeping them safe.

Dr Patricia Brekke, Co-Author from the Institute of Zoology, ZSL, said: “With this work we hope to provide vital evidence needed to understand how effective different management practices are at improving hatching success and aid population recovery. 

“Conservation managers are doing an amazing job of preventing species decline, but they have an incredibly difficult job of making decisions when species are at the brink of extinction, on what tools to implement, and when. This kind of work provides the evidence necessary to improve decision making and hopefully improve recovery.”

There are several factors that may explain why hatching rates have declined in recent decades, including populations dropping and extinction becoming more common. It is currently unclear, however, whether current population declines are being driven by increased hatching failure rates, or alternatively if reduced hatching is a consequence of population decline.

Ashleigh Marshall, Lead Author from the Institute of Zoology, ZSL and UCL, said: “Many of the previous comparisons of hatching failure across birds have typically excluded managed populations and have focused on non-threatened species only, which could mean we’ve been missing a big bit of the picture. 

“A key takeaway of this work is that it could show that populations already experiencing high rates of hatching failure are more likely to be taken into captivity or otherwise managed, which would indicate that conservation efforts are fittingly being targeted towards the species that need it most.”

The researchers have also called for a standardised definition of hatching failure, as their literature review revealed broad inconsistency with how it is defined and reported. This would help to track how hatching failure changes in the years to come, and may also benefit other types of egg-laying animals, such as reptiles and amphibians, where there are also widespread issues with hatching failure.

Ends

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JOURNAL

Biological Reviews

DOI

10.1111/brv.12931 

METHOD OF RESEARCH

Literature review

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Systematic review of avian hatching failure and implications for conservation

Texas A&M-led research team identifies oldest bone spear point In the Americas

The Manis bone projectile point represents the oldest direct evidence of mastodon hunting in the Americas.

Peer-Reviewed Publication

TEXAS A&M UNIVERSITY

 

IMAGE: THE MANIS SITE MASTODON RIB WITH EMBEDDED POINT TO THE LEFT view more 

CREDIT: CENTER FOR THE STUDY OF THE FIRST AMERICANS, TEXAS A&M UNIVERSITY

A team of researchers led by a Texas A&M University professor has identified the Manis bone projectile point as the oldest weapon made of bone ever found in the Americas at 13,900 years.

Dr. Michael Waters, distinguished professor of anthropology and director of Texas A&M’s Center for the Study of First Americans, led the team whose findings were published this week in Science Advances.

The team studied bone fragments embedded in a mastodon rib bone which was first discovered by Carl Gustafson, who conducted an excavation at the Manis site in Washington state from 1977 to 1979.

Using a CT scan and 3D software, Waters and his team isolated all the bone fragments to show it was the tip of a weapon – a projectile made from the bone of Mastodon, prehistoric relatives of elephants.

“We isolated the bone fragments, printed them out and assembled them,” Waters said. “This clearly showed this was the tip of a bone projectile point. This is this the oldest bone projectile point in the Americas and represents the oldest direct evidence of mastodon hunting in the Americas.”

Waters said at 13,900 years old, the Manis point is 900 years older than projectile points found to be associated with the Clovis people, whose stone tools he has also studied. Dating from 13,050 to 12,750 years ago, Clovis spear points have been found in Texas and several other sites across the country.

“What is important about Manis is that it’s the first and only bone tool that dates older than Clovis. At the other pre-Clovis site, only stone tools are found,” Waters said. “This shows that the First Americans made and used bone weapons and likely other types of bone tools.”

He said the only reason the Manis specimen was preserved is because the hunter missed, and the projectile got stuck in the mastodon’s rib.

“We show that the bone used to make the point appears to have come from the leg bone of another mastodon and was intentionally shaped into a projectile point form,” Waters said. “The spear with the bone point was thrown at the mastodon. It penetrated the hide and tissue and eventually came into contact with the rib. The objective of the hunter was to get between the ribs and impair lung function, but the hunter missed and hit the rib.” 

Waters studied the rib bone previously, presenting findings in a 2011 paper published in Science, in which radiocarbon dating determined the bone’s age and a genetic study of the bone fragments determined that they were mastodon.

“In our new study, we set out to isolate the bone fragments using CT images and 3D software,” he said. “We were able to create 3D images of each fragment and print them out at six times scale. Then we fit the pieces back together to show what the specimen looked like before it entered and splintered in the rib.” 

Not much is known about the people who used the Manis spear point other than they were some of the first Indigenous people to enter the Americas. Waters said the Manis site and others are giving archaeologists some insight. 

“It is looking like the first people that came to the Americas arrived by boat,” he said. “They took a coastal route along the North Pacific and moved south. They eventually got past the ice sheets that covered Canada and made landfall in the Pacific Northwest.

“It is interesting to note that in Idaho there is the 16,000-years-old Coopers Ferry site, in Oregon is the 14,100-year-old site of Paisley Caves. And here we report on the 13,900-year-old Manis site. So there appears to be a cluster of early sites in the Northwestern part of the United States that date from 16,000 to 14,000 years ago that predate Clovis. These sites likely represent the first people and their descendants that entered the Americas at the end of the last Ice Age.”

By Lesley Henton, Texas A&M University Division of Marketing & Communications

DOI

10.1126/sciadv.ade9068 

ARTICLE TITLE

Late Pleistocene osseous projectile point from the Manis site, Washington—Mastodon hunting in the Pacific Northwest 13,900 years ago

ARTICLE PUBLICATION DATE

1-Feb-2023

The team’s reconstruction of the bone point

A mastodon with an arrow pointing to the trajectory of the spear.

A close-up angle shows the bone point embedded in the mastodon's rib

A close-up angle shows the bone point embedded in the mastodon's rib.

CT scan of bone point fragments

CREDIT

Center for the Study of the First Americans, Texas A&M University

Remapping the superhighways travelled by the first Australians reveals a 10,000-year journey through the continent

Peer-Reviewed Publication

FLINDERS UNIVERSITY

 

IMAGE: FIG. 2. MAIN COMBINED MODEL INPUTS AND OUTPUTS. (A) FINE-SCALE (10 KM) RESOLUTION OF THE DOMINANT MOVEMENT CORRIDORS (‘SUPERHIGHWAYS’) DERIVED FROM CRABTREE ET AL. (2021) view more 

CREDIT: MAIN COMBINED MODEL INPUTS AND OUTPUTS. (A) FINE-SCALE (10 KM) RESOLUTION OF THE DOMINANT MOVEMENT CORRIDORS (‘SUPERHIGHWAYS’) DERIVED FROM CRABTREE ET AL. (2021)

New research has revealed that the process of ‘peopling’ the entire continent of Sahul — the combined mega continent that joined Australia with New Guinea when sea levels were much lower than today — took 10,000 years.  

New, sophisticated models combined recent improvements in demography and models of wayfinding based on geographic inference to show the scale of the challenges faced by the ancestors of Indigenous people making their mass migration across the supercontinent more than 60,000 years ago.

The ancestors of Aboriginal people likely first entered the continent 75,000–50,000 years ago from what is today the island of Timor, followed by later migrations through the western regions of New Guinea.

According to the new research, this pattern led to a rapid expansion both southward toward the Great Australian Bight, and northward from the Kimberley region to settle all parts of New Guinea and, later, the southwest and southeast of Australia.

The research was led by the ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH) and saw international experts in Australia and the United States collaborate to investigate the most likely pathways and the timeframe needed to reach population sizes able to withstand the rigours of their new environment.

By combining two existing models predicting the routes they took – ‘superhighways’ – and the demographic structure of these first populations, the researchers were able to estimate the time for continental saturation more precisely. The new research has just been published in the international journal Quaternary Science Reviews.

Based on detailed reconstructions of the topography of the ancient continent and models of past climate, the researchers developed a virtual continent and programmed populations to survive in and move successfully through their new territory.

Navigating by following landscape features like mountains and hills and knowing where to find water led to successful navigation strategies. The first people of Australia soon passed along cultural knowledge to subsequent generations facilitating the peopling of the whole continent.

Yet the challenges put forth by the topography of Sahul led to a slower pace of migration. Previous models did not take into account the topographic constraints that this sophisticated model does, allowing for a more realistic estimation of the peopling of the continent. This new work also explains the slower progress Indigenous ancestors made in reaching Tasmania, which was only made possible when seawaters across Bass Straight receded — a finding only possible by combining these model results.

The study’s lead author, Corey Bradshaw, Matthew Flinders Professor of Global Ecology at Flinders University and CABAH Models Theme Leader, says together these combined models allow for a better understanding of the archaeological and genetic data explaining the great migrations of Indigenous people in Sahul.

‘The ways that people interact with terrain, ecology, and potentially other people alter our model outcomes, providing more realistic results. Therefore, models that incorporate only demographic information without considering the resources and needs of travellers, as well as the opportunities and constraints to their travel, are likely to underestimate the timing of expansion into new regions. So, we now have a good prediction of the patterns and processes of how people first settled these lands tens of thousands of years ago.’

‘Our updated modelling shows that New Guinea was populated gradually over 5000 to 6000 years, with a focus initially on the Central Highlands and Arafura Sea area before reaching the Bismarck Archipelago in the east. The peopling of the far southeast and Tasmania is predicted to have occurred between 9000 and 10,000 years following initial arrival in Sahul.’

Professor Bradshaw says the innovative model developed by the researchers could be modified for other parts of the world to investigate the timing and patterns of initial peopling by humans.

‘Examining comparable patterns in regions of the Middle East as humans left north-eastern Africa, entry and spread into Europe, expansion across southern Asia, and movements from Alaska to South America, are all now possible using the same modelling approach.’

‘Because our model incorporates local conditions, including the spatial and temporal patterns of the land’s ability to provide food, the distribution of water sources, and topography, our migration patterns would be highly relevant when applied to other parts of the world.’

‘These results are surprising and very compelling,’ says Dr Stefani Crabtree, co-author of the study and Fellow at the Santa Fe Institute and Assistant Professor at Utah State University.

‘Our work shows that we need to keep in mind the constraints placed on travellers by the underlying geography as well as likely demographic scenarios. And as this work is based on our understanding of human movement globally, it can have massive implications for understanding migration in other places and other times. This also goes to show the power of combining computational models with archaeology and anthropology for refining our understanding of humanity.’

‘This type of work is a game changer.’

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JOURNAL

Quaternary Science Reviews

DOI

10.1016/j.quascirev.2023.107971 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Directionally supervised cellular automaton for the initial peopling of sahul

ARTICLE PUBLICATION DATE

2-Feb-2023

Decades-old crustaceans coaxed from lake mud give up genetic secrets revealing evolution in action

Peer-Reviewed Publication

UNIVERSITY OF OKLAHOMA

 

IMAGE: AN ANCIENT DAPHNIA PULICARIA INDIVIDUAL RESURRECTED FROM SOUTH CENTER LAKE (MINNESOTA, USA). THIS INDIVIDUAL WAS HATCHED FROM AN EGG RECOVERED FROM SEDIMENTS THAT DATE BACK TO CIRCA 1418-1301 A. D. OU SCIENTISTS HAVE RECENTLY STUDIED OTHER MEMBERS OF THIS SPECIES TO UNDERSTAND RAPID EVOLUTION TO HUMAN-CAUSED POLLUTION IN LAKE ECOSYSTEMS. view more 

CREDIT: DAGMAR FRISCH

Human actions are changing the environment at an unprecedented rate. Plant and animal populations must try to keep up with these human-accelerated changes, often by trying to rapidly evolve tolerance to changing conditions.

University of Oklahoma researchers Lawrence Weider, professor of biology, and Matthew Wersebe, a biology doctoral candidate, demonstrated rapid evolution in action by sequencing the genomes of a population of Daphnia pulicaria, an aquatic crustacean, from a polluted lake.  

The research, which was conducted as part of Wersebe’s doctoral dissertation, was recently published in the Proceedings of the National Academy of Sciences.  Wersebe and Weider revived decades-old Daphnia resting eggs from lake sediments, a method known as resurrection ecology, which has been refined in Weider’s lab over the past several decades. They then sequenced the entire genomes of 54 different Daphnia individuals from different points-in-time, allowing them to study the genetics and evolution of the population.

The Daphnia were collected from Tanners Lake, located in Oakdale, Minnesota. Tanners Lake has suffered significant salt pollution, stemming from the widespread use of road deicing salts in its watershed.  

Daphnia, also known as water fleas, play critical roles in environmental monitoring. For example, they have served as important test organisms in laboratories around the world for over a century because of their sensitivity to many environmental stressors such as chemicals. In nature, Daphnia act as a keystone species in freshwater food webs globally, where they feed on algae to help keep lake and reservoir water clean and serve as a food item for recreational and commercially important fish species.

Wersebe’s and Weider’s results indicate that rapid adaptation to salt pollution may allow lake Daphnia to persist in the face of anthropogenic salinization, maintaining the food webs and ecosystem services that Daphnia support. However, the ability of these populations to adapt will depend on the speed at which these changes are occurring and the underlying genetic makeup of the impacted populations. 

Over the past several years, many researchers have published results defining the scope and scale of lake salinization and recent research has highlighted the ecological impacts. However, to date, the evolutionary implications are not well known. Through their study, Wersebe and Weider reported signatures of natural selection throughout the genome near genes related to osmoregulation and ion regulation, key processes for dealing with high salt. Characterizing clones for salinity tolerance revealed evidence that genetic changes may underlie rapid evolution.  

“Work like this is the first step in designing future studies incorporating recent technological advances, such as CRISPR gene editing, allowing the creation of comprehensive genotype-to-phenotype maps and predicting the role that genetic variation plays in creating diverse forms and functions,” Wersebe said. “In fact, we found a promising gene that appears not to work properly in the older Daphnia, but a functional copy of the gene is increasing in frequency – true evolution in action.”

Future research using these advanced technologies for cutting and pasting the non-functional gene into Daphnia would be one way to better probe the effects that mutations have on complex phenotypic traits like salinity tolerance.  

The work was funded by the OU Department of Biology Adams Summer Scholarship, Robberson OU Graduate College Grant, Hill Fund for Research in Biology, OU Graduate Student Senate Research Grant, American Museum of Natural History Theodore Roosevelt Grant and the National Science Foundation Biogeography of Behavior student seed grant awarded to Wersebe in support of graduate research. The study was facilitated by material and technical assistance from the University of Oklahoma Biological Station in Kingston, Oklahoma, and the St. Croix Watershed Research Station in Marine-on-St. Croix, Minnesota.  

For more information, contact Wersebe at matthew.wersebe@ou.edu.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2217276120 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Resurrection genomics provides molecular and phenotypic evidence of rapid adaptation to salinization in a keystone aquatic species

ARTICLE PUBLICATION DATE

2-Feb-2023