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Can Gene Duplication Promote Evolution?

first_imgImagine you had no mouth but needed to eat.  A hamburger comes flying at you.  When it hits your body, your skin folds around it and pinches off, sealing it inside.  Dozens of 3-armed parts form a geodesic dome around it and carry it to the stomach.  Once delivered, all the parts are recycled for the incoming freedom fries.    If this sounds bizarre, it’s kind of what really happens in your cells.  Except for specialized channels that accept particular molecules, like water (12/20/2001 and salt (01/17/2002), a cell has no mouth; it is surrounded by a continuous membrane.  When large nutrients need to get in, the membrane has acceptors on the outside that signal a cascade of events.  The membrane dents inward and envelops the particle.  On the inside, proteins called clathrins form a geodesic structure around the incoming vesicle as the membrane pinches off and seals the contents inside.  Other proteins and enzymes stand at the ready to deliver the nutrient where needed.  This process goes on continually and is called endocytosis.  A press release from the University of Queensland says the cell eats its entire skin every 30 minutes.    Progress continues to be made understanding clathrin-mediated endocytosis since our 10/07/2003 entry, but the evolutionary origin of this elegant system seems illusory.  UC and Stanford biochemists writing in PNAS1 noted that two forms of clathrin are so different, being coded by different genes, they must have had separate evolutionary histories.  They propose this happened during gene duplication events up to 600 million years ago.    Andreas Wagner, however, publishing in Molecular Biology and Evolution,2 casts doubt on that method of evolutionary change:I here estimate the energy cost of changes in gene expression for several thousand genes in the yeast Saccharomyces cerevisiae.  A doubling of gene expression, as it occurs in a gene duplication event, is significantly selected against for all genes for which expression data is available.  It carries a median selective disadvantage of s > 10�5, several times greater than the selection coefficient s = 1.47 x 10�7 below which genetic drift dominates a mutant’s fate.  When considered separately, increases in messenger RNA expression or protein expression by more than a factor 2 also have significant energy costs for most genes.  This means that the evolution of transcription and translation rates is not an evolutionarily neutral process.  They are under active selection opposing them.  My estimates are based on genome-scale information of gene expression in the yeast S. cerevisiae as well as information on the energy cost of biosynthesizing amino acids and nucleotides.   (Emphasis added in all quotes.)Whatever the origin of clathrin, its reputation as a versatile molecule is growing.  In the April 28 issue of Nature,3 three Cambridge biologists wondered what it does when endocytosis is halted during cell division.  They discovered that clathrin has another essential job:Clathrin has an established function in the generation of vesicles that transfer membrane and proteins around the cell.  The formation of clathrin-coated vesicles occurs continuously in non-dividing cells, but is shut down during mitosis, when clathrin concentrates at the spindle apparatus.  Here, we show that clathrin stabilizes fibres of the mitotic spindle to aid congression of chromosomes.  Clathrin bound to the spindle directly by the amino-terminal domain of clathrin heavy chain.  Depletion of clathrin heavy chain using RNA interference prolonged mitosis; kinetochore fibres were destabilized, leading to defective congression of chromosomes to the metaphase plate and persistent activation of the spindle checkpoint.  Normal mitosis was rescued by clathrin triskelia [complete 3-part clathrin proteins] but not the N-terminal domain of clathrin heavy chain, indicating that stabilization of kinetochore fibres was dependent on the unique structure of clathrin.This is not just an incidental task for clathrin to do till cell division is over.  “The importance of clathrin for normal mitosis,” they say, “may be relevant to understanding human cancers that involve gene fusions of clathrin heavy chain.”1Wakeham et al., “Clathrin heavy and light chain isoforms originated by independent mechanisms of gene duplication during chordate evolution,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0502058102, published online before print May 9, 2005.2Andreas Wagner, “Energy Constraints on the Evolution of Gene Expression,” Molecular Biology and Evolution, 2005 22(6):1365-1374; doi:10.1093/molbev/msi126.3Royle et al., “Clathrin is required for the function of the mitotic spindle,” Nature 434, 1152-1157 (28 April 2005) | doi: 10.1038/nature03502.Gene duplication is one of the mechanisms Darwinists invoke when Natural Selection seems inadequate for a job, and they want to make it seem like there are other tricks in the toolkit of Charlie the Magician.  The abstract of Wagner’s paper seems to make it clear that duplication is not going to help.  If two tools are fighting each other, like front and rear tires spinning in opposite directions, the vehicle is not going anywhere.  Now go back and reread the 10/07/2003 entry about endocytosis and see if you think the Darwin Party has a prayer for explaining it.  Be sure to watch Allison Bruce’s cool video of clathrin making geodesic domes.  How many of you would vote for chance and natural selection producing this geometrical marvel?  Someone other than a Darwinist, who not only has a prayer but a Recipient, should get a hearing.(Visited 14 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

December 19, 2019 0

Willemse to push Junior World Champs

first_img10 May 2012South Africa’s Ashwin Willemse was recently selected by the International Rugby Board (IRB) to be the ambassador for its upcoming IRB Junior World Championship, which is contested by under-21 teams. In this capacity he’ll help to promote the event around South Africa, and build national excitement and support for it.The event takes place at Cape Town’s brand new UCT Stadium and Stellenbosch’s Danie Craven Stadium from 4 to 22 June.Willemse was previously a member of a junior World Cup-winning squad (which was known as the Under-21 World Cup at the time) when he made his national debut on the left wing for the South African team that took home the silverware at the 2002 event, played in South Africa.The coach of that team was Jake White, who went on to lead South Africa to Rugby World Cup glory in 2007.Player of the YearIn 2003, Willemse was selected to represent the Springboks at the Rugby World Cup in Australia. That same year he won three prestigious awards at the annual South African Rugby Awards, being named Player of the Year, the Players’ Player of the Year, and Most Promising Player of the Year.Four years later he was part of the World Cup winning team in France, making him one of the handful of players to have won both of the International Rugby Board’s (IRB) junior and senior championships.Willemse was capped 19 times in total, and scored five tries for his country, but injuries undermined what could have been an even better career.“The IRB Junior World Championship is a huge stepping stone for young players who aspire to be full internationals,” he said at the tournament’s launch event in Cape Town. “I’m looking forward to playing my part, to convince all Capetonians to get behind the tournament.”Pool BSouth Africa has been drawn in pool B along with England, Ireland and Italy. Their traditional arch-rivals Australia and New Zealand are playing in pools C and A respectively.The President of the South African Rugby Union, Oregan Hoskins, described Willemse as an outstanding role model for youngsters.“Ashwin is a shining example of what you can achieve through hard work, dedication and commitment,” he said. “As a teenager and later as a young adult, he rose above his challenging circumstances to establish himself as one of the best junior rugby players in the country and later as a worthy Springbok.”Although he grew up on the Cape Flats without a father and mentor, at school Willemse excelled at sport. Speaking at the Beyond Sport Summit in 2011, he named Namibian Olympic silver medallist Frankie Fredericks as one of his childhood heroes.‘You were not supposed to become anything’“Where we grew up,” he said, “you were not supposed to become anything, you were not supposed to achieve anything. You were limited to the walls and the boundaries of the school, and the boundaries of the town, and the gangs and drugs and violence that existed in your immediate environment.”In his first year of high school Willemse encountered his first mentor, an English teacher and sports coach named Andre de Bruin, who took the gifted young sportsman under his wing.De Bruin’s patronage wasn’t enough to prevent Willemse from succumbing to the temptation of gangs and drugs. He eventually became an addict and a member of the notorious Americans gang, and saw several of his friends die in gang-related violence.But throughout those turbulent times, Willemse retained his passion for rugby. The turning point came in 1999, when former Springbok wing Breyton Paulse, another of Willemse’s heroes, visited his school to talk to the kids. At the time Willemse was 17 years old, with massive potential but was, in his own words, a “juvenile delinquent with no future”.Willemse was introduced to the affable Paulse, who was informed that the youngster had been selected for the annual national provincial schools rugby festival, the Craven Week – known as a scouting ground for future national stars – but had no rugby kit to take with him. Paulse donated a kit bag with all the essentials to help Willemse get to the tournament and, touched by the gesture, Willemse made the commitment to leave his life of crime behind.Breyton Paulse’s 50th test jerseyIn 2002, Willemse was selected for the junior national team, replacing none other than Paulse on the wing. Two years later the two players were teammates on a tour to the UK, and after the second test match against Ireland – which happened to be Paulse’s 50th test – Willemse asked him for his specially printed shirt as a souvenir.When Paulse questioned Willemse’s request, the latter player reminded him of the day when, as a high school pupil, his life was changed by Paulse’s kindness. “He didn’t realise that boy was me,” said Willemse.The rugby star attributes much of his success to the fact that he was fortunate enough to have good people come his way at crucial times, who helped and guided him on the right path.In 2009 Willemse retired from international rugby and is these days a popular motivational speaker. He is also a member of the Supersport television panel of rugby analysts.SA under-20 preparationsIn April, the South African under-20 team wrapped up a series victory over Argentina’s Pumitas, winning two games and drawing the third. The South Americans were on a whirlwind tour ahead of the world championships.“We are very proud of the ways our boys played. We proved that we can be competitive at an international level and this gives us the confidence we need to prepare for June,” said coach Dawie Theron.“This tour was a great learning experience even for us coaches. We now know how ready our players are for the JWC and what we still need to work on.”The team has since been announced and includes a number of players with experience in the Sevens and Super Rugby international tournaments.The 28-man squad includes Blue Bulls’ flank Wian Liebenberg as captain, Vodacom Cheetahs’ flyhalf Johan Goosen (whose participation is questionable because of injury), DHL Stormers’ prop Steven Kitshoff, and up-and-coming flyhalf Tony Jantjies, the younger brother of Springbok flyhalf Elton.South Africa start their campaign with a game against Ireland at the Danie Craven Stadium on 4 June.First published by MediaClubSouthAfrica.com – get free high-resolution photos and professional feature articles from Brand South Africa’s media service.last_img read more

December 18, 2019 0

OR: a visionary leader

first_imgBrand South Africa CEO, Kingsley Makhubela, shares his thoughts on leadership from former African National Congress (ANC) leader, Oliver Reginald (OR) Tambo, who passed away in 1993. This year marks the centenary of Tambo’s birth.Oliver Tambo displayed an important quality when it comes to leadership: the ability to provide solutions to current challenges, says Brand South Africa CEO, Kingsley Makhubela. (Image: Melissa Javan)Kingsley MakhubelaThe most important quality when it comes to leadership is to provide solutions for current challenges and inspire people to work towards a better future for all.Because the past is over and cannot be changed, leaders who want to project confidence and the impression that they are in control of events talk optimistically of the future, often emphasising that today’s sacrifices will pay dividends down the road, observe the US business theorists Jeffrey Pfeffer and Robert Sutton.The leadership qualities demonstrated by late ANC president Oliver Reginald (OR) Tambo provide an eloquent illustration of this principle.Moreover, the ability to project into the future was evident in his diplomatic skills, particularly when he drafted one of the ANC’s strategic documents for negotiations with the apartheid government, the Harare Declaration. It was later adopted by the UN General Assembly as the Declaration on Apartheid and its Destructive Consequences in Southern Africa.The document articulates conditions under which the negotiations regarding the South African conflict should take place.Following the end of the Cold War, the late 1980s were characterised by fundamental changes regarding conflict resolution. During this time, Tambo realised the importance of having a framework for negotiation on the South African conflict. The Harare Declaration was drafted in anticipation of possible negotiations, brought on by global changes after the end of the Cold War.Once the declaration was adopted at the Summit of the Frontline Heads of State, it was escalated to the meeting of the then Organisation of African Unity (OAU) held in Addis Ababa, Ethiopia, in July 1989.The presentation of this declaration to the OAU’s summit of heads of state was an act of brilliance on the part of Tambo, given that some leaders doubted its merits. Tambo’s diplomatic skills were fundamental to ensuring the unanimous adoption of the declaration at that summit.Tambo understood that the opposition of even a single country had the potential to derail the adoption of the document by world leaders at the UN General Assembly. His grasp of the value of UN consensus and political support underlined his resolve to present a united front by African states at the UN.A step aheadThe document was finalised within a short time. I have no doubt that Tambo’s health was severely affected by the work he needed to complete before the General Assembly gathering in September 1989. I remember him missing his annual medical checkup because he had to prioritise gaining the support of all frontline member states regarding changes to the document, as mandated by the OAU summit.As always, Zambia’s then president Kenneth Kaunda provided him with a plane to fly to all the frontline states to finalise these changes.Tambo flew to six countries in three days and accomplished his mission. The gruelling travel demands contributed to his suffering the stroke which eventually took his life. I cannot forget that day: Wednesday, 9 August 1989. It was the day Tambo made the supreme sacrifice to ensure that there was a viable framework for the negotiation of a democratic South Africa.A closer look at the UN Declaration highlights the fact that one needs to appreciate Tambo’s understanding of the Westphalian political order, which has at its core the notion of state sovereignty.To this end, the declaration is divided into sections dealing with the principles of a future democratic South Africa based on constitutionality, the rule of law and an independent, nonracial judiciary.Our constitutional democracy is rooted in Tambo’s sterling work, which provided a climate for negotiations by spelling out what the apartheid regime needed to do to create conditions conducive for negotiations.Scholars on the subject of negotiation suggest that some form of compromise by both sides during the negotiation process is a key enabling condition for success. However, Tambo was a step ahead of them in the way that he had structured the Harare Declaration. He ensured that the onus was on the apartheid regime to level negotiations by undertaking to unconditionally release political prisoners, lift the ban on political parties, end the state of emergency and cease all political trials.These concessions were to be made by the apartheid regime without the expectation of any concession on the ANC’s part.Tambo was aware that once the apartheid regime made some positive steps, there would be an expectation for the other side to make concessions.But concessions by those opposing the apartheid regime would be tantamount to capitulation by liberation forces in the face of blatant power asymmetry at the negotiation table.The declaration was equally unequivocal when it came to guidelines regarding the process of negotiations. To this end, Tambo was strategic in ensuring that the declaration articulated the parameters of the negotiation process with regard to the role of the international community. He ensured that the international community underwrote the negotiation process to guarantee a positive outcome.The UN Declaration made it clear that the dismantling of the apartheid regime in its entirety was the only item for negotiation. In its programme of action, the document spelt out steps that needed to be taken to dismantle apartheid, and mandated that, based on progress during negotiations, sanctions should be gradually lifted. The road map to the integration of South Africa into the global community was stipulated by the declaration.Finally, certain aspects of the Declaration on Apartheid and its Destructive Consequences in Southern Africa found expression in our Constitution, thanks to Tambo’s leadership and vision. South Africans will be eternally grateful for this.Follow on Makhubela on twitter @[email protected] @Brand_SA CEO was the key note speaker at the OR Tambo Exhibition launch #ORTambo100 pic.twitter.com/fJZyUebAV7— Tsabeng (@tsabengr) August 23, 2017This is an edited version of the keynote address at the launch of an exhibition at Johannesburg’s Apartheid Museum marking the centenary of Oliver Tambo’s birth.Would you like to use this article in your publication or on your website? See Using Brand South Africa material.last_img read more

December 18, 2019 0

Kenya’s take on Adele’s “Hello”

first_imgKenyan Afropop singer Dela Maranga has offered a fresh take on the popular song Hello from Brit singer Adele. Maranga sings the song in Swahili and it’s going viral on YouTube. It has already been viewed more than 250 000 times. Kenyan Afropop star Dela Maranga has covered Adele’s hit single “Hello” in Swahili and it is getting international acclaim. (Photo: Adele, screengrab via YouTube/ Maranga, Facebook) • Former child soldier turns his story into a graphic novel • Infographic: Africa’s best brands  • From Nollywood to New Nollywood: the story of Nigerian film’s runaway success  • Gallery: South Africa’s rich and colourful heritage  • African history gets animation treatment Priya PitamberThe smash hit Hello by the British singer-songwriter, Adele, has already been covered numerous times, even though the song, which was released at the end of October, is barely two months old.Kenyan Afropop songbird Dela Maranga decided to sing her rendition in Swahili, except for the word “hello”. And the cover has been receiving critical acclaim from international publications.Elle magazine described it as a version “that stands out above the rest”.Evan Real from the American publication, Harper’s Bazaar, wrote: “Even if you can’t fully understand what Maranga is belting, know that it is still okay to cry. Because obviously, an Adele inspired sob session is inescapable – no matter what language you speak.”US lifestyle portal Refinery 29 reads: “The rhythm and musicality of the song translate effortlessly, and an emphasis on a little added percussion adds just the right note to keep this version feeling fresh.“Maranga’s gorgeous voice more than does the song justice.”On Twitter, Maranga admitted that she had fun performing the song.Watch her version here:How do you think it compares to Adele’s hit:Maranga started singing when she was seven years old, as a member of a choir. She moved on to backing vocals and in 2008, she started to sing professionally. “At only 19, her debut on the big stage was her collaboration with Kenya’s most famous boy band, Sauti Sol, that saw her song MAMA PAPA make a record number one hit for 18 weeks on Kenya’s most popular reggae radio station Metro FM,” reads her profile on her Facebook page.RT Blavity: Adele’s “Hello” in Swahili is the best thing you’ll hear today https://t.co/6Q4HybXbi2 #nowplaying … https://t.co/Y54GxzKGxL — #nowplaying (@now_playing___) December 16, [email protected] you should do a duet with Dela Maranga she has a cover of Hello in Swahili. It’s beautiful. Would do more for world peace than the UN — David Stalker (@DavidStalker) December 14, 2015last_img read more

December 18, 2019 0

Punjab rivers in spate, 600 families rescued

first_imgAs heavy rains lashed Punjab during the past three days, leaving its rivers Sutlej, Ravi and Beas in spate, a flood-like situation was witnessed in many parts of the State on Monday. Punjab Chief Minister Captain Amarinder Singh on Monday announced ₹100 crore for emergency relief and rehabilitation measures in the flood-hit regions of the State and said a special ‘Girdawari’ will be conducted as soon as the water level recedes to ensure adequate compensation for the affected farmers.The Chief Minister made these announcements during a tour of the flood-affected areas of Rupnagar district. Capt. Amarinder also expressed grief over the death of three persons due to roof collapse in Ludhiana district on Sunday.Rupnagar Deputy Commissioner Sumeet Jarangal informed the Chief Minister that due to heavy downpour in Rupnagar district the total release at Ropar headworks was 2,50,000 cusecs, in addition to unprecedented increase in flow in many rivulets like Swan Nadi (90,000 cusecs), Sirsa Nadi (60,000 cusecs), and Budhki Nadi (20,000 cusecs). “The district administration rescued more than 600 families from 45 villages. While there had been no reports of loss of human life there was significant loss of crops and cattle which was being assessed,” he said.Later, the Chief Minister held a meeting to review the flood situation in the State with senior officials. During the meeting it was revealed that the overall situation in the rivers Beas and Ravi was under control though danger continued to lurk in areas adjacent to the Sutlej river and further downstream, at Harike headworks in Ferozepur. The flood releases from the Bakhra dam was above its maintainable level, flowing currently at 1681.23 feet, an official statement said. Meanwhile, the National Disaster Response Force and State Disaster Response Force have been stationed at villages in Jalandhar. Deputy Commissioner Jalandhar Varinder Kumar Sharma said keeping in view the alarming situation due to release of 2,40,000 cusecs of water from Ropar headwork, companies of NDRF and SDRF have been stationed at vulnerable points in Shahkot, Nakodar and Phillaur. Also, Army authorities have also been requested to station their companies at all these sub-divisions so that they could help the administration in case of any need, he added. Flood relief teams of the Army under the Western Command are actively carrying out rescue operations in various areas of Punjab and Haryana. Teams of strengths of 60-70 persons each with requisite equipment and resources have been deployed at Mirthal in Pathankot district, Dinanagar in Gurdaspur district, Phillaur, Nakodar, and Shahkot in Jalandhar district and near Karnal in Haryana.A total of 15 persons have been rescued so far from various areas, said an official statement. In neighbouring Haryana, a flood-like situation was seen in many parts. The Indian Air Force rescuing nine persons stuck in Karnal district owing to the rise of water in the Yamuna river.last_img read more

December 1, 2019 0