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Human Genomes Shaped by Past Events that Caused Sharp Dips in the Population

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Representation of the impact of a founder event on genetic data with an initial population made of various genomic segments that were inherited identical-by-descent (IBD) from a common ancestor. Following a founder event, the diversity of IBD segments is reduced and due to recombination events, the length of these IBD segments shortens gradually—these two parameters are thus informative about the founder strength and age, respectively. CREDIT Rémi Tournebize and Priya Moorjani (

The genomes of many human populations show evidence of founder events, which occur when a small number of initial members start a new population, and can lead to low genetic diversity as well as increase the risk of certain genetic diseases in the new population. Rémi Tournebize and Priya Moorjani of the University of California, Berkeley report these new findings in the open access journal PLOS Genetics.

Founder events can occur when a population experiences a sharp decrease in numbers or when a few individuals colonize an isolated environment, such as an island. Despite the large impact that founder events can have on a population’s genetics, we know few details of how these events have shaped the evolution of humans and other species.

To better understand these past events, researchers developed a new technique called ASCEND that uses genomic analysis to estimate the timing and strength of founder events. In the new study, they applied ASCEND to analyze about 460 human populations worldwide. The researchers found that over half of the populations that they analyzed had evidence of recent founder events, including most living hunter-gatherer, nomadic and indigenous groups that were sampled. These founder events are associated with geographic isolation, a hunter-gatherer lifestyle, or the cultural practice of marrying within your own group or religion.

The researchers also analyzed about 200 modern dog populations and found that most populations show signs of extreme founder events. These events occurred within the last 25 generations, coinciding with the start of dog breeding during Victorian times, and may be related to inbreeding and the use of a few highly prized males to sire numerous litters.

The new analysis technique will help scientists to identify groups that experienced strong founder events and that may be at high risk of certain genetic diseases. Ashkenazi Jews and Finns, who experienced strong founder events, often undergo genetic screening to learn about their pre-disposition to certain genetic diseases. The study found that several populations among Native Americans, Oceanians, and South Asians have experienced even more extreme founder events than Ashkenazi Jews, and so these populations may also benefit from genetic screening.

“Some human populations like Ashkenazi Jews or Finns have been extensively studied in population genetics and have helped researchers identify many disease-causing mutations,” say the researchers. “Hence, we wanted to study if other populations have a similar history that could enable further progress in medical genetics. We were surprised to see how widespread the history of founder events is in humans, both in present-day and ancient DNA samples, suggesting that investigation of disease-causing variants will be fruitful to identify and reduce disease burden among contemporary groups.”

Republished courtesy of PLOS. 

 

 

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Arena resuscitation: Coun. Sharp to head up committee overseeing work on Calgary Event Centre – Calgary | Globalnews.ca

Arena resuscitation: Coun. Sharp to head up committee overseeing work on Calgary Event Centre - Calgary | Globalnews.ca

Calgary’s new event centre committee held its inaugural meeting Monday to chart a course for the work it’s been tasked with over the coming months.

The meeting, held mostly behind closed doors, saw Ward 1 Coun. Sonya Sharp appointed as committee chair and a meeting schedule approved.

Sharp, Ward 8 Coun. Courtney Walcott and Ward 13 Coun. Dan McLean were the representatives from city council chosen after the committee’s formation was unanimously approved after a lengthy closed door council meeting last month.

Read more:

Calgary city council strikes committee to oversee work on event centre project

Brad Parry, president of Calgary Economic Development, and Deborah Yedlin, president of the Calgary Chamber of Commerce, were also selected to sit on committee as citizen members and Yedlin was elected to serve as vice-chair on Monday.

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“The goal is to have an event centre,” Sharp told reporters following the meeting. “It’s not if, it’s when, and this committee is really to make sure it oversees the work of administration and that we get the job done.”

The committee is scheduled to meet once every month through to October, but how much information about what happens in those meetings to be shared with Calgarians remains unclear.


Click to play video: 'Calgary Flames organization pulls out of new arena deal with city due to rising costs'







Calgary Flames organization pulls out of new arena deal with city due to rising costs


Calgary Flames organization pulls out of new arena deal with city due to rising costs – Dec 22, 2021

Sharp said their goal is to be transparent with citizens on the progress of the work that’s underway.

“We need to make sure that there is transparency with this,” Sharp said. “Not to say that there wasn’t before, but this is a different time with this project.

“We need to make sure that we’re keeping that trust and confidence with our partners, the citizens and the rest of the business community, and transparency is key to that.”

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According to Sharp, the committee will not be “negotiating any sort of deals,” but rather overseeing administration and the work of the third party organization, which will be undertaking that work.

The committee was created after the collapse of the original project with the Calgary Sports and Entertainment Corporation (CSEC) prior to construction.

Read more:

City council seeks 3rd party to ‘start fresh,’ find partners for Calgary Event Centre

The committee is also being tasked with building on the work already undertaken by the event centre assessment committee. That committee, chaired by then-Ward 6 councillor Jeff Davison, was formed in 2018 by the previous city council to develop a partnership framework, financial strategy and determine a location to build a new event centre.​

“We’re committed to ensuring that we get this right for the city,” Walcott said. “That’s really at the core of our mandate here: that we provide something that is of high value to the city and that’s something that all of us share in common.”

The previous deal with CSEC came to a close near the end of December 2021 with the corporation citing rising costs as a key issue to not move forward.


Click to play video: 'Calgary city council creates committee to oversee work on event centre project'







Calgary city council creates committee to oversee work on event centre project


Calgary city council creates committee to oversee work on event centre project – Mar 8, 2022

In January, city council voted unanimously voted to find a third party to begin talks again with CSEC. Though the third party has yet to be announced, its job will be to gauge CSEC’s interest to come back to the drawing board, along with seeking other parties who may want to be involved with the project.

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A report released in summer 2021 pegged the project at $608.5 million, which forced both Flames ownership and the city back to the table to make adjustments to the agreement.

The costs jumped again after the Calgary Planning Commission added several climate resiliency and infrastructure conditions as a normal part of the approval process for the building’s development permit, which totaled around $16 million.

The City of Calgary offered up $6.4 million to assist with the added costs, but Flames ownership notified Mayor Jyoti Gondek just before Christmas that the organization was pulling out of the agreement.

Construction was slated to begin on the project in early 2022.

–with files from Jessika Guse, Global News

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