(Press-News.org) Every cuckoo is an adopted child – raised by foster parents, into whose nest the cuckoo mother smuggled her egg. The cuckoo mother is aided in this subterfuge by her resemblance to a bird of prey. There are two variants of female cuckoos: a gray morph that looks like a sparrowhawk, and a rufous morph. Male cuckoos are always gray.
“With this mimicry, the bird imitates dangerous predators of the host birds, so that they keep their distance instead of attacking,” says Professor Jochen Wolf from LMU Munich. Together with researchers at CIBIO (Centro de Investigação em Biodiversidade e Recursos Genéticos, Portugal), the evolutionary biologist has investigated the genetic foundations of the variant coloring, which is limited to females and emerged over the long evolutionary arms race between host and cuckoo.
Hypotheses from behavioral research propose that the rarer color morph always has an advantage, because the host birds gradually get wise to the trick. If, for example, there are many sparrowhawk-like cuckoos or many sparrowhawks, the host birds learn over time to distinguish whether the bird in front of them is a sparrowhawk or a cuckoo. “Then the advantage of the rufous morph comes into play, as it is less common and has not been learned by the hosts,” says Wolf. Which variant the host birds learn depends on the abundance both of the cuckoos and of the birds of prey.
Only the female line counts
Only female cuckoos who have to get close to the host nests have these color morphs. “We would therefore expect these color variants – so-called polymorphisms – to be fixed somewhere in the female genome,” says Wolf. Whereas in humans it is males who carry a sex-specific chromosome, the Y chromosome, in birds it is females who have a sex chromosome, the W chromosome. With his team, Wolf has now demonstrated that the mutations for the color morphs are in fact located either on the W chromosome or in mitochondria, which are also passed down exclusively along the maternal line.
The researchers also showed that a sister species of the cuckoo, the Oriental cuckoo, possesses the same color morphs and mutations. “Consequently, the mutations already existed in a common ancestor and are therefore older than the speciation,” says Wolf. The evolutionary biologist sees this as a strong indicator that the rarer variant does actually always have an advantage: Where there are two variants, the better one normally wins out. But if the rarer of two variants always has an advantage, the system oscillates and settles into a certain frequency. “This causes the genetic variation to be maintained for a long time,” says Wolf. “Our results support the intriguing possibility that numerous other traits that are sex-specific but more difficult to investigate are genetically encoded on the matrilinear genome like the color polymorphism of the female cuckoo.”
END
Color variants in cuckoos: the advantages of rareness
Rufous or gray: LMU evolutionary biologists show that the color variants of female cuckoos are based on ancient mutations
2024-04-24
ELSE PRESS RELEASES FROM THIS DATE:
Laser technology offers breakthrough in detecting illegal ivory
2024-04-24
A new way of quickly distinguishing between illegal elephant ivory and legal mammoth tusk ivory could prove critical to fighting the illegal ivory trade. A laser-based approach developed by scientists at the Universities of Bristol and Lancaster, could be used by customs worldwide to aid in the enforcement of illegal ivory from being traded under the guise of legal ivory. Results from the study are published in PLOS ONE today [24 April].
Despite the Convention on the International Trade in Endangered Species (CITES) ban on ivory, poaching associated with its illegal trade has ...
Why can’t robots outrun animals?
2024-04-24
Robotics engineers have worked for decades and invested many millions of research dollars in attempts to create a robot that can walk or run as well as an animal. And yet, it remains the case that many animals are capable of feats that would be impossible for robots that exist today.
“A wildebeest can migrate for thousands of kilometres over rough terrain, a mountain goat can climb up a literal cliff, finding footholds that don't even seem to be there, and cockroaches can lose a leg and not slow down,” ...
After spinal cord injury, neurons wreak havoc on metabolism
2024-04-24
COLUMBUS, Ohio – Conditions such as diabetes, heart attack and vascular diseases commonly diagnosed in people with spinal cord injuries can be traced to abnormal post-injury neuronal activity that causes abdominal fat tissue compounds to leak and pool in the liver and other organs, a new animal study has found.
After discovering the connection between dysregulated neuron function and the breakdown of triglycerides in fat tissue in mice, researchers found that a short course of the drug gabapentin, commonly prescribed for nerve pain, prevented ...
Network model unifies recency and central tendency biases
2024-04-24
Neuroscientists have revealed that recency bias in working memory naturally leads to central tendency bias, the phenomenon where people’s (and animals’) judgements are biased towards the average of previous observations. Their findings may hint at why the phenomenon is so ubiquitous.
Researchers in the Akrami Lab at the Sainsbury Wellcome Centre at UCL and the Clopath Lab at Imperial College London developed a network model with a working memory module and another accounting for sensory histories. The study, published in eLife, describes how the model shows neural circuits ...
Ludwig Lausanne scientists identify and show how to target a key tumor defense against immune attack
2024-04-24
April 24, 2024, NEW YORK – A Ludwig Cancer Research study has discovered how a lipid molecule found at high levels within tumors undermines the anti-cancer immune response and compromises a recently approved immunotherapy known as adoptive cell therapy (ACT) using tumor infiltrating lymphocytes, or TIL-ACT. In this individualized cell therapy, TILs—CD8+ T cells that kill cancer cells—are expanded in culture from a patient’s tumor samples and reinfused into the patient as a treatment.
Researchers led by Ludwig Lausanne’s Matteo ...
Can climate change accelerate transmission of malaria? Pioneering research sheds light on impacts of temperature
2024-04-24
In 2022, an estimated 249 million malaria cases killed 608,000 people in 85 countries worldwide including the United States, according to the World Health Organization.
Malaria continues to pose a considerable public health risk in tropical and subtropical areas, where it impacts human health and economic progress.
Despite concerns about the potential impact of climate change on increasing malaria risk, there is still limited understanding of how temperature affects malaria transmission – until now.
Malaria is a mosquito-borne disease caused by a parasite that spreads from bites of infected female Anopheles mosquitoes. If left untreated in humans, malaria can cause severe symptoms, ...
A new attempt to identify salt gland development and salt resistance genes of Limonium bicolor ——Identification of bHLH gene family and its function analysis in salt gland development
2024-04-24
The secondary salinization of saline-alkali land is increasing globally. It is of strategic significance to explore the salt-tolerant molecular mechanism of halophytes and cultivate saline-alkali resistant crops for the improvement of saline-alkali land. The recretohalophyte Limonium bicolor has a unique salt-secreting structure, salt gland, which can directly excrete Na+ out of the body to effectively avoid salt stress. Exploring the development mechanism of salt gland structure in recretohalophyte is of great significance for analyzing the development of plant epidermis structure and improving the salt-resistant mechanism of plants.
Recently, Wang ...
The SAPIENS Podcast named finalist at the 16th Annual Shorty Awards
2024-04-24
SAPIENS: A Podcast for Everything Human has been named as a 16th Annual Shorty Awards finalist in the Science and Technology Podcast Category.
The Shorty Awards honor the best work in digital and social media by the most creative and influential brands, agencies, organizations, and individuals whose work has excelled in creativity, strategy, and effectiveness.
SAPIENS’s work has demonstrated outstanding performance across the judging criteria, which makes it a top contender for a Shorty Award in a most competitive year. The work is also eligible for ...
Startup financing gender gaps greater in societies where women are more empowered
2024-04-24
Commercial bankers provide capital to fund the operations and growth of businesses. However, as these lenders evaluate entrepreneurs who apply for loans, gender bias leads to women being denied more often than their male counterparts.
Estimates show a $1.7 trillion financing gap worldwide for small- and medium-sized enterprises owned by women.
Studies show that when women do secure business loans, the amounts tend to be smaller, have higher interest rates and require more collateral, which restricts the economic potential of women-led ventures. However, findings ...
Postpartum depression after adolescent stress shows a dysregulated HPA axis: a cross-species translational study
2024-04-24
BIRMINGHAM, Ala. – Adverse life events are a known and predominant risk factor for postpartum depression in women after delivery of their baby. Furthermore, the postpartum depression in women who have experienced adverse life events tends to be refractory to treatment.
In a study using a mouse model and human subjects, researchers from the University of Alabama at Birmingham and Johns Hopkins Medicine show that stress from adolescent social isolation in mice elicits a prolonged elevation of corticosterone levels and glucocorticoid signaling, which in turn results ...
LAST 30 PRESS RELEASES:
Einstein Probe releases its Science White Paper
Music-based therapy may improve depressive symptoms in people with dementia
No evidence that substituting NHS doctors with physician associates is necessarily safe
At-home brain speed tests bridge cognitive data gaps
CRF appoints Josep Rodés-Cabau, M.D., Ph.D., as editor-in-chief of structural heart: the journal of the heart team
Violent crime is indeed a root cause of migration, according to new study
Customized smartphone app shows promise in preventing further cognitive decline among older adults diagnosed with mild impairment
Impact of COVID-19 on education not going away, UM study finds
School of Public Health researchers receive National Academies grant to assess environmental conditions in two Houston neighborhoods
Three Speculum articles recognized with prizes
ACM A.M. Turing Award honors two researchers who led the development of cornerstone AI technology
Incarcerated people are disproportionately impacted by climate change, CU doctors say
ESA 2025 Graduate Student Policy Award Cohort Named
Insomnia, lack of sleep linked to high blood pressure in teens
Heart & stroke risks vary among Asian American, Native Hawaiian & Pacific Islander adults
Levels of select vitamins & minerals in pregnancy may be linked to lower midlife BP risk
Large study of dietary habits suggests more plant oils, less butter could lead to better health
Butter and plant-based oils intake and mortality
20% of butterflies in the U.S. have disappeared since 2000
Bacterial ‘jumping genes’ can target and control chromosome ends
Scientists identify genes that make humans and Labradors more likely to become obese
Early-life gut microbes may protect against diabetes, research in mice suggests
Study raises the possibility of a country without butterflies
Study reveals obesity gene in dogs that is relevant to human obesity studies
A rapid decline in US butterfly populations
Indigenous farming practices have shaped manioc’s genetic diversity for millennia
Controlling electrons in molecules at ultrafast timescales
Tropical forests in the Americas are struggling to keep pace with climate change
Brain mapping unlocks key Alzheimer’s insights
Clinical trial tests novel stem-cell treatment for Parkinson’s disease
[Press-News.org] Color variants in cuckoos: the advantages of rarenessRufous or gray: LMU evolutionary biologists show that the color variants of female cuckoos are based on ancient mutations