̽��ֱ�� of Cambridge - Emily Mitchell

Earth’s earliest sea creatures drove evolution by stirring the water

jg533 — Fri, 17 May 2024 15:01:02 +0000

A study involving the ̽��ֱ�� of Cambridge has used virtual recreations of the earliest animal ecosystems, known as marine animal forests, to demonstrate the part they played in the evolution of our planet.

Using state-of-the-art computer simulations of fossils from the Ediacaran time period - approximately 565 million years ago - scientists discovered how these animals mixed the surrounding seawater. This may have affected the distribution of important resources such as food particles and could have increased local oxygen levels.

Through this process, the scientists think these early communities could have played a crucial role in shaping the initial emergence of large and complex organisms prior to a major evolutionary radiation of different forms of animal life, the so-called Cambrian ‘explosion’.

Over long periods of time, these changes might have allowed life forms to perform more complicated functions, like those associated with the evolution of new feeding and movement styles.

̽��ֱ��study was led by the Natural History Museum and is published today in the journal Current Biology.

Dr Emily Mitchell at the ̽��ֱ�� of Cambridge’s Department of Zoology, a co-author of the report, said: “It’s exciting to learn that the very first animals from 580 million years ago had a significant impact on their environment, despite not being able to move or swim. We’ve found they mixed up the water and enabled resources to spread more widely - potentially encouraging more evolution.”

Scientists know from modern marine environments that nutrients like food and oxygen are carried in seawater, and that animals can affect water flow in ways that influence the distribution of these resources.

To test how far back this process goes in Earth’s history, the team looked at some of the earliest examples of marine animal communities, known from rocks at Mistaken Point, Newfoundland, Canada. This world-famous fossil site perfectly preserves early life forms thanks to a cover of volcanic ash (sometimes referred to as an ‘Ediacaran Pompeii’).

Although some of these life forms look like plants, analysis of their anatomy and growth strongly suggests they are animals. Owing to the exceptional preservation of the fossils, the scientists could recreate digital models of key species, which were used as a basis for further computational analyses.

First author Dr Susana Gutarra, a Scientific Associate at the Natural History Museum, said: “We used ecological modelling and computer simulations to investigate how 3D virtual assemblages of Ediacaran life forms affected water flow. Our results showed that these communities were capable of ecological functions similar to those seen in present-day marine ecosystems.”

̽��ֱ��study showed that one of the most important Ediacaran organisms for disrupting the flow of water was the cabbage-shaped animal Bradgatia, named after Bradgate Park in England. ̽��ֱ��Bradgatia from Mistaken Point are among some of the largest fossils known from this site, reaching diameters of over 50 centimetres.

Through their influence on the water around them, the scientists believe these Ediacaran organisms might have been capable of enhancing local oxygen concentrations. This biological mixing might also have had repercussions for the wider environment, possibly making other areas of the sea floor more habitable and perhaps even driving evolutionary innovation.

Dr Imran Rahman, lead author and Principal Researcher at the Natural History Museum, said: “ ̽��ֱ��approach we’ve developed to study Ediacaran fossil communities is entirely new in palaeontology, providing us with a powerful tool for studying how past and present marine ecosystems might shape and influence their environment.”

̽��ֱ��research was funded by the UK Natural Environment Research Council and the US National Science Foundation.

Reference: Gutarra-Diaz, S. “Ediacaran marine animal forests and the ventilation of the oceans.” May 2024, Current Biology. DOI: 10.1016/j.cub.2024.04.059

Adapted from a press release by the Natural History Museum

3D reconstructions suggest that simple marine animals living over 560 million years ago drove the emergence of more complex life by mixing the seawater around them

It’s exciting to learn that the very first animals from 580 million years ago had a significant impact on their environment, despite not being able to move or swim.

Emily Mitchell

Hugo Salais, Metazoa Studio

Artistic recreation of the marine animal forest

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Explore life in the Universe with new postgraduate programme

lw355 — Mon, 18 Sep 2023 10:00:19 +0000

A new postgraduate programme will train researchers to understand life's origins, search for habitable planets and consider the most profound question of all: are we alone?

Humanity’s quest to discover the origins of life in the universe

sc604 — Wed, 08 Mar 2023 17:10:32 +0000

For thousands of years, humanity and science have contemplated the origins of life in the Universe. While today’s scientists are well-equipped with innovative technologies, humanity has a long way to go before we fully understand the fundamental aspects of what life is and how it forms.

“We are living in an extraordinary moment in history,” said Professor Didier Queloz, who directs the Leverhulme Centre for Life in the Universe at Cambridge and ETH Zurich’s Centre for Origin and Prevalence of Life. While still a doctoral student, Queloz was the first to discover an exoplanet – a planet orbiting a star other than our Sun. ̽��ֱ��discovery led to him being awarded the 2019 Nobel Prize in Physics.

In the three decades since Queloz’s discovery, scientists have discovered more than 5,000 exoplanets. Trillions more are predicted to exist within our Milky Way galaxy alone. Each exoplanet discovery raises more questions about how and why life emerged on Earth and whether it exists elsewhere in the universe.

Technological advancements, such as the James Webb Space Telescope and interplanetary missions to Mars, give scientists access to huge volumes of new observations and data. Sifting through all this information to understand the emergence of life in the universe will take a big, multidisciplinary network.

In collaboration with chemist and fellow Nobel Laureate Jack Szostak and astronomer Dimitar Sasselov, Queloz announced the formation of such a network at the American Association for the Advancement of Science (AAAS) meeting in Washington, DC. ̽��ֱ��Origins Federation brings together researchers studying the origins of life at Cambridge, ETH Zurich, Harvard ̽��ֱ��, and ̽��ֱ�� ̽��ֱ�� of Chicago.

Together, Federation scientists will explore the chemical and physical processes of living organisms and environmental conditions hospitable to supporting life on other planets. “ ̽��ֱ��Origins Federation builds upon a long-standing collegial relationship strengthened through a shared collaboration in a recently completed project with the Simons Foundation,” said Queloz.

These collaborations support the work of researchers like Dr Emily Mitchell from Cambridge's Department of Zoology. Mitchell is co-director of Cambridge’s Leverhulme Centre for Life in the Universe and an ecological time traveller. She uses field-based laser-scanning and statistical mathematical ecology on 580-million-year-old fossils of deep-sea organisms to determine the driving factors that influence the macro-evolutionary patterns of life on Earth.

Speaking at AAAS, Mitchell took participants back to four billion years ago when Earth’s early atmosphere - devoid of oxygen and steeped in methane – showed its first signs of microbial life. She spoke about how life survives in extreme environments and then evolves offering potential astrobiological insights into the origins of life elsewhere in the universe.

“As we begin to investigate other planets through the Mars missions, biosignatures could reveal whether or not the origin of life itself and its evolution on Earth is just a happy accident or part of the fundamental nature of the universe, with all its biological and ecological complexities,” said Mitchell.

̽��ֱ��founding centres of the Origins Federation are ̽��ֱ��Origins of Life Initiative (Harvard ̽��ֱ��), Centre for Origin and Prevalence of Life (ETH Zurich), the Center for the Origins of Life ( ̽��ֱ�� of Chicago), and the Leverhulme Centre for Life in the Universe ( ̽��ֱ�� of Cambridge).

̽��ֱ��Origins Federation will pursue scientific research topics of interest to its founding centres with a long-term perspective and common milestones. It will strive to establish a stable funding platform to create opportunities for creative and innovative ideas, and to enable young scientists to make a career in this new field. ̽��ֱ��Origins Federation is open to new members, both centres and individuals, and is committed to developing the mechanisms and structure to achieve that aim.

“ ̽��ֱ��pioneering work of Professor Queloz has allowed astronomers and physicists to make advances that were unthinkable only a few years ago, both in the discovery of planets which could host life and the development of techniques to study them,” said Professor Andy Parker, head of Cambridge's Cavendish Laboratory. “But now we need to bring the full range of our scientific understanding to bear in order to understand what life really is and whether it exists on these newly discovered planets. ̽��ֱ��Cavendish Laboratory is proud to host the Leverhulme Centre for Life in the Universe and to partner with the Origins Federation to lead this quest.”

Scientists from the ̽��ֱ�� of Cambridge, ETH Zurich, Harvard ̽��ֱ��, and the ̽��ֱ�� of Chicago have founded the Origins Federation, which will advance our understanding of the emergence and early evolution of life, and its place in the cosmos.

ETH Zurich/NASA

L-R: Emily Mitchell, Didier Queloz, Kate Adamal, Carl Zimmer

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Vice-Chancellor’s awards showcase ̽��ֱ��’s societal impact and public engagement

ta385 — Mon, 14 Oct 2019 14:54:26 +0000

Now in their fourth year, the awards were made in four categories: collaboration, early career, established researcher/academic champion and professional service.

Winners in the collaboration category included PhD student Christoph Franck for an initiative creating a global air pollution sensor network driven by citizen science.

̽��ֱ��early career researchers included Jessica Miller whose project has changed understandings of mental health and trauma in UK policing, informing a new wellbeing service and leading to discussion in Parliament.

Among those commended as established researchers, Vincent Gnanapragasam developed a new tool to predict an individual’s prognosis following a prostate cancer diagnosis to help make decisions about the value of treatment. In a very different field, David Trippett was recognised for bringing an ‘indecipherable’ opera back to life through international performances, broadcasts and recordings.

In the professional services category Naomi Chapman from the Polar Museum Education team developed maps to enable young and partially sighted people to explore the Arctic and Antarctic by touch.

̽��ֱ��announcement was made at a prize ceremony held at the Old Schools on 14 October 2019.

Professor Stephen Toope, Vice-Chancellor of the ̽��ֱ�� of Cambridge, says: “This year’s nominations recognise impressive and inspirational individuals, and strongly reflect our mission to engage the public, tackle real-world problems and improve people’s lives. ̽��ֱ��award scheme focuses attention on the increasingly important role that institutions such as ours have to play in restoring faith in experts.”

̽��ֱ��Vice-Chancellor’s Research Impact and Engagement Awards were established to recognise and reward outstanding achievement, innovation and creativity in devising and implementing ambitious engagement and impact plans that have the potential to create significant economic, social and cultural impact from and engagement with and for research. Each winner receives a £1,000 grant to be used for the development and delivery of engagement/impact activity or relevant training.

This year’s winners are:

Collaboration Award

Emily Mitchell (Department of Earth Sciences)

Researchers and museum specialists collaborated on a museum exhibition and public programme, engaging a range of public audiences with research on the earliest fossils to illuminate the start of complex life.

Helen Strudwick ( ̽��ֱ��Fitzwilliam Museum)

This collaborative project engages audiences with our pioneering research on ancient Egyptian coffin construction and decoration, through a major exhibition, ‘Pop-Up’ museum targeting underserved audiences and digital resources.

Open-Seneca

Open-seneca is a student-led initiative creating a global low-cost mobile air pollution sensor network driven by citizen science. ̽��ֱ��aim of the initiative is to empower citizens with air pollution data to raise awareness, initiate behaviour change, and inform policy makers on environmental issues. ̽��ֱ��team are: Christoph Franck, Charles Christensen, Lorena Gordillo Dagallier, Sebastian Horstmann, Raphaël Jacquat and Peter Pihlman Pedersen.

Early Career Award

Saumya Saxena (Faculty of History)

Saumya’s research focuses on family law and gender in India. She advised the twenty-first Law Commission of India on reform of family law and worked with the Verma Commission on amendments to law relating to rape in India.

Jessica Miller (Department of Sociology)

Jessica’s project involved engaging with over 18000 police officers and staff to change the face of trauma resilience in UK policing, and inviting commitment from decision-makers to inform national policy and operational change.

Matthew Agarwala (Bennett Institute for Public Policy)

Matthew’s research on valuing natural resources is helping in the transition to sustainable economic growth. Having been adopted by the United Nations and other bodies, his work is shaping standards for measurement.

Zoë Fritz (School of Clinical Medicine)

Zoë’s research around resuscitation decisions led to the development of the ReSPECT process (“Recommended Summary Plan for Emergency Care and Treatment”), which has replaced problematic ‘DNACPR’s with tremendous impact on policy, practice, guidelines and beneficiaries.

Established Researcher and Academic Champion

Nicholas Thomas (Museum of Archaeology and Anthropology)

In 2018, Nicholas co-curated the landmark exhibition 'Oceania' at the Royal Academy in London. Based on collaborative research at Cambridge, the exhibition brought a dynamic, contemporary view of the art of an extraordinary region to European audiences.

Vincent Gnanapragasam (School of Clinical Medicine)

Vincent is the Chief Investigator for PREDICT Prostate, the first individualized prognostic tool accessible to both clinicians and patients to help make unbiased informed decisions about the value of treatment for newly diagnosed prostate cancer.

David Trippett (Faculty of Music)

An unheard opera by 19th-century composer Franz Liszt languished silently in a manuscript thought fragmentary and illegible. David’s meticulous reconstruction brought it to life, to global acclaim, through international performances, broadcasts and recordings.

Professional Service

Oliver Francis (Centre for Diet and Activity Research, and the MRC Epidemiology Unit)

Oliver’s leadership in communications has transformed the impact strategies at CEDAR and the MRC Epidemiology Unit. His innovative contributions span all aspects of the communications and impact portfolio.

Naomi Chapman (Scott Polar Research Institute)

With a local artist, Naomi developed innovative maps of the Arctic and Antarctic with which hundreds of young and partially sighted people have enjoyed a touch tour of polar research.

Twelve students, academics and professional members of staff from across the ̽��ֱ�� of Cambridge have received Vice-Chancellor’s Research Impact and Engagement Awards in areas as diverse as prostate cancer, family law, museum public engagement and police mental health.

This year’s nominations recognise impressive and inspirational individuals, and strongly reflect our mission to engage the public, tackle real-world problems and improve people’s lives

Professor Stephen Toope

Candy Welz

Airam Hernández and Joyce El-Khoury perform Sardanapalo at Staatskapelle Weimar

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Why life on Earth first got big

sc604 — Mon, 25 Jun 2018 14:52:12 +0000

̽��ֱ��research, led by the ̽��ֱ�� of Cambridge, found that the most successful organisms living in the oceans more than half a billion years ago were the ones that were able to ‘throw’ their offspring the farthest, thereby colonising their surroundings. ̽��ֱ��results are reported in the journal Nature Ecology and Evolution.

Prior to the Ediacaran period, between 635 and 541 million years ago, life forms were microscopic in size, but during the Ediacaran, large, complex organisms first appeared, some of which – such as a type of organism known as rangeomorphs – grew as tall as two metres. These organisms were some of the first complex organisms on Earth, and although they look like ferns, they may have been some of the first animals to exist – although it’s difficult for scientists to be entirely sure. Ediacaran organisms do not appear to have mouths, organs or means of moving, so they are thought to have absorbed nutrients from the water around them.

As Ediacaran organisms got taller, their body shapes diversified, and some developed stem-like structures to support their height.

In modern environments, such as forests, there is intense competition between organisms for resources such as light, so taller trees and plants have an obvious advantage over their shorter neighbours. “We wanted to know whether there were similar drivers for organisms during the Ediacaran period,” said Dr Emily Mitchell of Cambridge’s Department of Earth Sciences, the paper’s lead author. “Did life on Earth get big as a result of competition?”

Mitchell and her co-author Dr Charlotte Kenchington from Memorial ̽��ֱ�� of Newfoundland in Canada examined fossils from Mistaken Point in south-eastern Newfoundland, one of the richest sites of Ediacaran fossils in the world.

Earlier research hypothesised that increased size was driven by the competition for nutrients at different water depths. However, the current work shows that the Ediacaran oceans were more like an all-you-can-eat buffet.

“ ̽��ֱ��oceans at the time were very rich in nutrients, so there wasn’t much competition for resources, and predators did not yet exist,” said Mitchell, who is a Henslow Research Fellow at Murray Edwards College. “So there must have been another reason why life forms got so big during this period.”

Since Ediacaran organisms were not mobile and were preserved where they lived, it’s possible to analyse whole populations from the fossil record. Using spatial analysis techniques, Mitchell and Kenchington found that there was no correlation between height and competition for food. Different types of organisms did not occupy different parts of the water column to avoid competing for resources – a process known as tiering.

“If they were competing for food, then we would expect to find that the organisms with stems were highly tiered,” said Kenchington. “But we found the opposite: the organisms without stems were actually more tiered than those with stems, so the stems probably served another function.”

According to the researchers, one likely function of stems would be to enable the greater dispersion of offspring, which rangeomorphs produced by expelling small propagules. ̽��ֱ��tallest organisms were surrounded by the largest clusters of offspring, suggesting that the benefit of height was not more food, but a greater chance of colonising an area.

“While taller organisms would have been in faster-flowing water, the lack of tiering within these communities shows that their height didn’t give them any distinct advantages in terms of nutrient uptake,” said Mitchell. “Instead, reproduction appears to have been the main reason that life on Earth got big when it did.”

Despite their success, rangeomorphs and other Ediacaran organisms disappeared at the beginning of the Cambrian period about 540 million years ago, a period of rapid evolutionary development when most major animal groups first appear in the fossil record.

̽��ֱ��research was funded by the Natural Environment Research Council, the Cambridge Philosophical Society, Murray Edwards College and Newnham College, Cambridge.

Reference
Emily G. Mitchell and Charlotte G. Kenchington. ‘ ̽��ֱ��utility of height for the Ediacaran organisms of Mistaken Point.’ Nature Ecology and Evolution (2018). DOI: 10.1038/s41559-018-0591-6

Inset image:
A close-up view of the Mistaken Point ‘E’ surface community. Credit: Emily Mitchell.

Some of the earliest complex organisms on Earth – possibly some of the earliest animals to exist – got big not to compete for food, but to spread their offspring as far as possible.

Reproduction appears to have been the main reason that life on Earth got big when it did.

Emily Mitchell

CG Kenchington

Artist’s reconstruction of the community at Lower Mistaken Point

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Earliest evidence of reproduction in a complex organism

sc604 — Mon, 03 Aug 2015 15:00:00 +0000

Researchers led by the ̽��ֱ�� of Cambridge have found the earliest example of reproduction in a complex organism. Their new study has found that some organisms known as rangeomorphs, which lived 565 million years ago, reproduced by taking a joint approach: they first sent out an ‘advance party’ to settle in a new area, followed by rapid colonisation of the new neighbourhood. ̽��ֱ��results, reported today in the journal Nature, could aid in revealing the origins of our modern marine environment.

Using statistical techniques to assess the distribution of populations of a type of rangeomorph called Fractofusus, the researchers observed that larger ‘grandparent’ rangeomorphs were randomly distributed in their environment, and were surrounded by distinct patterns of smaller ‘parents’ and ‘children’. These patterns strongly resemble the biological clustering observed in modern plants, and suggest a dual mode of reproduction: the ‘grandparents’ being the product of ejected waterborne propagules, while the ‘parents’ and ‘children’ grew from ‘runners’ sent out by the older generation, like strawberry plants.

Rangeomorphs were some of the earliest complex organisms on Earth, and have been considered to be some of the first animals – although it’s difficult for scientists to be entirely sure. They thrived in the oceans during the late Ediacaran period, between 580 and 541 million years ago, and could reach up to two metres in length, although most were around ten centimetres. Looking like trees or ferns, they did not appear to have mouths, organs, or means of moving, and probably absorbed nutrients from the water around them.

Like many of the life forms during the Ediacaran, rangeomorphs mysteriously disappeared at the start of the Cambrian period, which began about 540 million years ago, so it has been difficult to link rangeomorphs to any modern organisms, or to figure out how they lived, what they ate and how they reproduced.

“Rangeomorphs don’t look like anything else in the fossil record, which is why they’re such a mystery,” said Dr Emily Mitchell, a postdoctoral researcher in Cambridge’s Department of Earth Sciences, and the paper’s lead author. “But we’ve developed a whole new way of looking at them, which has helped us understand them a lot better – most interestingly, how they reproduced.”

Mitchell and her colleagues used high-resolution GPS, spatial statistics and modelling to examine fossils of Fractofusus, in order to determine how they reproduced. ̽��ֱ��fossils are from south-eastern Newfoundland in Canada, which is one of the world’s richest sources of fossils from the Ediacaran period. Since rangeomorphs were immobile, it is possible to find entire ecosystems preserved exactly where they lived, making them extremely suitable for study via spatial techniques.

̽��ֱ��‘generational’ clustering patterns the researchers observed fit closely to a model known as a nested double Thomas cluster model, of the type seen in modern plants. These patterns suggest rapid, asexual reproduction through the use of stolons or runners. At the same time, the random distribution of larger ‘grandparent’ Fractofusus specimens suggests that they were the result of waterborne propagules, which could have been either sexual or asexual in nature.

“Reproduction in this way made rangeomorphs highly successful, since they could both colonise new areas and rapidly spread once they got there,” said Mitchell. “ ̽��ֱ��capacity of these organisms to switch between two distinct modes of reproduction shows just how sophisticated their underlying biology was, which is remarkable at a point in time when most other forms of life were incredibly simple.”

̽��ֱ��use of this type of spatial analysis to reconstruct Ediacaran organism biology is only in its infancy, and the researchers intend to extend their approach to further understand how these strange organisms interacted with each other and their environment.

̽��ֱ��research was funded by the Natural Environment Research Council.

Reference:
Mitchell, E. et al., Reconstructing the reproductive mode of an Ediacaran macro-organism, Nature (2015), DOI: 10.1038/nature14646

Inset image: A group of Fractofusus specimens from the ‘E’ surface, Mistaken Point Ecological Reserve, Newfoundland, Canada Credit: AG Liu

A new study of 565 million-year-old fossils has identified how some of the first complex organisms on Earth – possibly some of the first animals to exist – reproduced, revealing the origins of our modern marine environment.

Rangeomorphs don’t look like anything else in the fossil record, which is why they’re such a mystery

Emily Mitchell

C. G. Kenchington

Artist's reconstruction of the Fractofusus community on the H14 surface at Bonavista Peninsula

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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