evolution Archives - News@91��ɫ

91��ɫ U led research sheds light on earliest days of Earth’s formation

egamulin — Wed, 26 Mar 2025 16:34:59 +0000

Faculty of Science prof used novel approach of applying fluid dynamics and chemistry to planetary sciences for modelling study published in Nature

Wednesday March 26, TORONTO – New research led by a 91��ɫ professor sheds light on the earliest days of the Earth’s formation and potentially calls into question some earlier assumptions in planetary science about the early years of rocky planets. Establishing a direct link between the Earth’s interior dynamics occurring within the first 100 million years of its history and its present-day structure, the work is one of the first in the field to combine fluid mechanics with chemistry to better understand the Earth's early evolution.

“This study is the first to demonstrate, using a physical model, that the first-order features of Earth’s lower mantle structure were established four billion years ago, very soon after the planet came into existence,” says lead author Faculty of Science Assistant Professor in the Department of Physics and Astronomy at 91��ɫ.

The mantle is the rocky envelopment that surrounds the iron core of rocky planets. The structure and dynamics of the Earth’s lower mantle play a major role throughout Earth’s history as it dictates, among others, the cooling of the Earth’s core where the Earth’s magnetic field is generated.

Boukaré – originally from France – worked with research colleagues from his former institution, Université Paris Cité's James Badro and Henri Samuel, on the paper, , which was published today in Nature.

Boukaré says that while seismology, geodynamics, and petrology have helped answer many questions about the present-day thermochemical structure of Earth’s interior, a key question remained: how old are these structures, and how did they form? Trying to answer this, he says, is much like looking at a person in the form of an adult versus a child and understanding how the energetic conditions will not be the same.

Artistic view of Earth’s interior during mantle solidification in the first hundreds of millions of years of Earth’s history. Gravitational segregation of dense, iron-rich magma (in orange) likely formed a basal magma ocean atop the core, that can explain the present-day structure of the lower mantle.

“If you take kids, sometimes they do crazy things because they have a lot of energy, like planets when they are young. When we get older, we don't do as many crazy things, because our activity or level of energy decreases. So, the dynamic is really different, but there are some things that we do when we are really young that might affect our entire life,” he says “It’s the same thing for planets. There are some aspects of the very early evolution of planets that we can actually see in their structure today.”

To better understand old planets, we must first learn how young planets behave.

Since simulations of the Earth’s mantle focus mostly on present-day solid-state conditions, Boukaré had to develop a novel model to explore the early days of Earth when the mantle was much hotter and substantially molten, work that he has been doing since his PhD.

Boukaré’s model is based on a multiphase flow approach that allows for capturing the dynamics of magma solidification at a planetary scale. Using his model, he studied how the early mantle transitioned from a molten to a solid state. Boukaré and his team were surprised to discover that most of the crystals formed at low pressure, which he says creates a very different chemical signature than what would be produced at depth in a high-pressure environment. This challenges the prevailing assumptions in planetary sciences in how rocky planets solidify.

“Until now, we assumed the geochemistry of the lower mantle was probably governed by high-pressure chemical reactions, and now it seems that we need to account also for their low-pressure counterparts.”

Boukare says this work could also help predict the behaviour of other planets down the line.

“If we know some kind of starting conditions, and we know the main processes of planetary evolution, we can predict how planets will evolve.”

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91��ɫ is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for success. 91��ɫ's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact:

Emina Gamulin, 91��ɫ Media Relations, 437-217-6362, egamulin@yorku.ca

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Unexpected diversity of light-sensing proteins goes beyond vision in frogs

egamulin — Mon, 17 Jun 2024 14:31:34 +0000

91��ɫ U prof fills gaps in current understanding of opsins responsible for circadian rhythms

TORONTO, June 17, 2024 — This Thursday marks the first day of summer in the Northern hemisphere, the longest day of the year. Living beings have evolved over many millennia to react to varying amounts of sunlight exposure, governing everything from sleep-wake cycles, seasonal changes and more, but the proteins responsible for responding to different light environments for non-visual purposes are an under explored area of science. , led by a 91��ɫ Faculty of Science professor and a former 91��ɫ researcher, found that frogs have maintained a shocking number, and diversity, of these light-sensing proteins, called opsins, over evolutionary time.

Assistant Professor Ryan Schott

“We, and other animals, have many different types of nonvisual opsins and they can be present in different parts of the body including the eyes, brain, and skin. Right now, the days are getting longer as we approach summer and nonvisual opsins are involved in how our bodies respond to those differences,” says in the Department of Biology & Centre for Vision Research. “We found that frogs, despite being a largely nocturnal group, actually maintain more of these nonvisual opsin genes than any other group that is ancestrally nocturnal.”

Nonvisual opsins are found throughout the animal kingdom. In humans and other mammals, information about lighting conditions enters through the eye and is sent to the pineal gland, which will respond to light by suppressing or secreting hormones. This is an indirect process, but frogs still have a directly light sensing “third eye” that others in the animal kingdom lost long ago.

“There are several nonvisual opsins present in that organ in the top of the head, and that is going to help them regulate their day and night cycles,” says Schott. “Something interesting we found though was that most of these opsins are also still expressed in the eye, so the eye is still having a large role to play in light detection functions that aren't directly related to vision.”

Frogs, the researchers said, provide an opportunity to study the proteins under diverse ecological conditions. To investigate this diversity in frogs, the researchers combined genetic data from transcriptomes — the genetic sequences of all genes expressed in an organ — from the eyes of 81 frog species with publicly available genomes and multi-tissue transcriptome data from 21 additional species. These 102 species provided a broad sampling of frogs with different ecological adaptations.

“Frogs are cool because different species can live in the water, on land, in trees, or even underground,” says former Schott and Bell lab researcher Jack Boyette, lead author on the paper and current doctoral student at Penn State. “This gets further complicated by things like activity period — a lot of frog species are active at night, but some are active during the daytime. As you can imagine, all these different habitats have very distinct light environments, which has implications for the evolution and the function of sensory systems.”

The researchers say several groups, including mammals and snakes, have lost many opsin genes through the course of evolution, which might be explained by going through an evolutionary period where they lived nocturnally and the ability to sense light was not as important.

Frogs are also an ancestrally nocturnal group, so the researchers expected to find reduced nonvisual opsin diversity in frogs. Remarkably, the frog genomes assessed in this study contained all 18 ancestral vertebrate nonvisual opsins. This surprising finding may result from complex life histories.

“Within the lifetime of a single animal, many frog species transition between drastically different light environments,” Boyette said. “Even though a lot of adult frogs are nocturnal, that's not necessarily true of the larval tadpoles.”

Additionally, the researchers identified genetic differences in opsins between groups with differing ecologies, life histories, and body types. This could potentially indicate that frog nonvisual opsins have adapted to specific lifestyles or environments, similar to findings in Schott’s last study which looked at the visual opsins in frogs’ eyes.

Other members of the research team include Rayna C Bell, California Academy of Sciences and National Museum of Natural History, Smithsonian Institution; Matthew K Fujita and Kate N Thomas, University of Texas at Arlington; Jeffrey W Stretcher and David J Gower, Natural History Museum of London.

The findings were published today in the journal Molecular Biology and Evolution.

Schott says this study has given first hints about how opsin genes whose functions are currently unknown might operate in frogs and they’ve identified a candidate gene that may be involved in regulating seasonal breeding in frogs.

“We still need a better understanding of the specific functions of each type of nonvisual opsin and how those functions have evolved and adapted in different animals, like the frogs in our study, to meet their specific needs,” says Schott. “It's a really exciting step towards a better understanding these seasonal patterns and how frogs and other animals use light in different ways to regulate their biological functions.”

About 91��ɫ

91��ɫ is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for success. 91��ɫ’s fully bilingual Glendon Campus is home to Southern Ontario’s Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contacts: Emina Gamulin, 91��ɫ Media Relations and External Communications, 437-217-6362, egamulin@yorku.ca

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The life aquatic: a game changer for frog vision, but little difference between night and day, 91��ɫ-led study finds

egamulin — Thu, 04 Apr 2024 14:09:01 +0000

Ancestral legacy and continued present-day advantages may explain why diurnal frog species kept genes adapted to night vision

April 4, 2024, Toronto – Frogs display a remarkable diversity of species as a whole, but does the same hold true for their visual abilities? led by 91��ɫ’s Faculty of Science sought to answer this question by collaborating with researchers in Australia, Belgium, Brazil, Cameroon, Ecuador, Equatorial Guinea, French Guiana, Gabon, Seychelles, Sweden, United Kingdom and the United States, to get a sample of a diverse array of frogs to study the visual pigments found in their eyes.

Frogs display a large amount of diversity in their eye pigments, but the study did not find a large difference between nocturnal and diurnal frogs.

Prof. Ryan Schott

“Through this large international collaborative effort, we were able to study the pigments of frogs from all over the world who have adapted to myriad environments, and for the most part, we found this diversity is ‘reflected’ in the pigments in frogs’ eyes,” says research lead and Assistant Professor in the Department of Biology Ryan Schott.

“We saw this pattern of visual evolution being driven by differences in species that are either aquatic as adults, or that are living on the ground, or trees. On the other hand, we didn’t find much of a difference with the small groups of frogs that have adapted to daytime conditions as opposed to their nocturnal cousins.”

The study, published today in Molecular Biology and Evolution, examined the frog visual system by looking at the visual pigments and other genes in the eyes of a diverse selection of frogs living in vastly different light environments. Visual pigments are the molecules in the photoreceptor cells of the retina that are responsible for detecting light and then sending signals to the brain to perceive that light.

“We humans, as well as many animals, have these pigments in our eyes that actually absorb and respond to light,” explains Schott, also with the Centre for Vision Research at 91��ɫ and former research associate with the National Museum of Natural History at the Smithsonian Institution in Washington, D.C. “It's the differences in these pigments that allow us to see at night versus in the day, and allow us to perceive colour differences. So, we were interested in how these pigments have evolved in these frogs in different light environments.”

Schott, who studies the visual system of vertebrates in his lab located at 91��ɫ’s Keele Campus, has previously looked at vision changes of southern leopard frogs as they metamorphose from aquatic tadpoles to frogs living on land, and found a lot of differences. However, the lack of difference between the diurnal and nocturnal frogs came as a surprise. While it is possible that differences were not captured in the method of research, Schott says their evolutionary heritage may provide an alternate explanation.

“Most frogs are nocturnal, and so ancestrally, they really have this visual system that's adapted to these nocturnal environments,” he says. “This is probably suggesting that even the diurnal animals need these adaptations to survive because of course, they could say, get woken up in the night by a predator and then need to use their visual system to escape.”

About 91��ɫ

91��ɫ is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for success. 91��ɫ’s fully bilingual Glendon Campus is home to Southern Ontario’s Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contacts: Emina Gamulin, 91��ɫ Media Relations and External Communications, 437-217-6362, egamulin@yorku.ca

The post The life aquatic: a game changer for frog vision, but little difference between night and day, 91��ɫ-led study finds appeared first on News@91��ɫ.

Maternal instincts lead to social life of bees

roshanp — Fri, 26 Feb 2021 15:34:47 +0000

The social life of bees: once solitary, behaviour plays a role in gene selection for socialness

TORONTO, Feb. 26, 2021 – The maternal care of offspring is one of the behavioural drivers that has led some bee species to have an ever-expanding social life over the history of evolution, new research out of 91��ɫ has found.

The face of Ceratina calcarate female carpenter bee. Photo by Sandra Rehan

By virtue of being in a social group, the genome itself may respond by selecting more social rather than non-social genes. The behaviour and social environment come first setting the stage for future molecular evolution.

In addition, the researchers have found that a similar genetic evolution happened independently in different species at different times, suggesting there is a unifying principle leading to the same social trait.

“There seems to be something about sociality specifically that is driving the genome to evolve in this way. It’s a very interesting finding previously reported only in ants and honeybees,” says lead researcher Associate Professor of the Faculty of Science.

A founding nest female Ceratina_calcarata carpenter bee in a nest. Photo by Sandra Rehan

Rehan and her team looked at 16 different bee species across three different independent origins of eusociality – the transition from solitary to social life in which bees or other species live in a multigenerational group cooperatively caring for offspring where there is a reproductive division of labour.

They also sequenced the genome of six of the carpenter bee species – one from North America, three from Australia, one from Japan and another from Kenya – to find out how sociability effects genome evolution. They found that caring for the species’ young in a group has in many cases led to the selection of social rather than non-social gene regulation.

“When we see the rise of queens and workers in complex sociality, we tend to see a rise of more complex genomic signatures, rates of evolution in the genome, but also the complexity of the structure of the genomes,” says Rehan. “We know so little about how sociality evolves.”

A Ceratina_calcarata carpenter bee. Photo by Sandra Rehan

Most bees are solitary, but some, like honeybees and carpenter bees, have transitioned to being social. Overall, though, sociality is relatively rare in the animal kingdom, and in bees.

“We are trying to understand how life evolved from simple to complex. We’re mostly interested in how they got there. By studying these kinds of intermediatory groups and simple societies, we really can ask that question empirically,” says Rehan.

“It gives us a window into the evolution of complexity and behaviour broadly. We can study it very practically in insects and bees because they show remarkable diversity in behaviour, but it gives us insights into all animals, including ourselves.”

The research was published today in the Nature journal, .

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91��ɫ is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91��ɫ's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact:

Sandra McLean, 91��ɫ Media Relations, 416-272-6317, sandramc@yorku.ca

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