Evolutie in het Nieuws #3

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Op donderdag 10 september 2015 19:27 schreef Molurus het volgende:
Resten nieuwe mensachtige soort ontdekt in Zuid-Afrika

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Onderzoekers hebben resten van een nieuwe mensachtige soort ontdekt en de soort 'homo naledi' (ster) gedoopt, naar de vindplaats; een grot in Zuid-Afrika.

De volwassen man was 1,50 meter lang, woog 45 kilo en zijn schouders hadden meer weg van een mensaap.

De eerste vondsten van resten werden al in 2013 gedaan. Volgens onderzoeker John Hawks van de universiteit van Wisconsin oogt de 'sterrenmens' als een van de primitiefste mensachtigen die ooit zijn gevonden.

De naledi had een brein ter grootte van een sinaasappel, de helft van het brein van de moderne mens. Hij had aapachtige kromme vingers, maar voeten die nauwelijks te onderscheiden zijn van de onze.

Meer: nu.nl

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Op vrijdag 11 september 2015 09:23 schreef Gehenna het volgende:
Interessant nieuws weer Zoals eigenlijk altijd wel in dit topic.

Maar toch moet ik zeggen: Schedels kussen

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Op zaterdag 21 november 2015 10:55 schreef Semisane het volgende:
Evolution Is Finally Winning Out Over Creationism
A majority of young people endorse the scientific explanation of how humans evolved.

[...]

Now, at long last, there seems to be hope: National polls show that creationism is beginning to falter, and Americans are finally starting to move in favor of evolution. After decades of legal battles, resistance to science education, and a deeply rooted cultural divide, evolution may be poised to win out once and for all.

The people responsible for this shift are the young. According to a recent Pew Research Center report, 73 percent of American adults younger than 30 expressed some sort of belief in evolution, a jump from 61 percent in 2009, the first year in which the question was asked. The number who believed in purely secular evolution (that is, not directed by any divine power) jumped from 40 percent to a majority of 51 percent. In other words, if you ask a younger American how humans arose, you’re likely to get an answer that has nothing to do with God.

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Bron Slate.com

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Op zaterdag 21 november 2015 10:55 schreef Semisane het volgende:
Evolution Is Finally Winning Out Over Creationism
A majority of young people endorse the scientific explanation of how humans evolved.

[...]

Now, at long last, there seems to be hope: National polls show that creationism is beginning to falter, and Americans are finally starting to move in favor of evolution. After decades of legal battles, resistance to science education, and a deeply rooted cultural divide, evolution may be poised to win out once and for all.

The people responsible for this shift are the young. According to a recent Pew Research Center report, 73 percent of American adults younger than 30 expressed some sort of belief in evolution, a jump from 61 percent in 2009, the first year in which the question was asked. The number who believed in purely secular evolution (that is, not directed by any divine power) jumped from 40 percent to a majority of 51 percent. In other words, if you ask a younger American how humans arose, you’re likely to get an answer that has nothing to do with God.

[...]

Bron Slate.com

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Evolution by natural selection, Darwin wrote, mainly depends on “success in leaving progeny.”1 He also recognized that such success may be achieved by “dependence of one being on another.” When are individuals most successful living on their own, and when can they benefit from working with others?

It’s not always an easy question to answer. For parasites living in or on other organisms, for example, maximizing reproduction is a tricky proposition. Using more host resources lets parasites produce more offspring, but overexploitation shortens host life span, reducing the amount of time the parasites have to reproduce. So it may make sense for parasites to avoid harming their hosts, and parasites that increase host life span may fare even better. As British evolutionary biologist and geneticist John Maynard Smith noted more than 100 years after Darwin’s musings on reproduction and cooperation, you shouldn’t kill the goose that lays the golden eggs.2

But Maynard Smith recognized that this strategy is based on a critical assumption: that if you do not kill the golden goose, no one else will either. [...]

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Modern humans adopted innate immune genes responsible for recognizing invading microbes from Neanderthals and Denisovans, according to two studies published today (January 7) in The American Journal of Human Genetics. The two teams, based in France and Germany, independently concluded that humans picked up some versions of a cluster of toll-like receptors by interbreeding with archaic hominin relatives.

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Grootste mensaap ooit ging aan eigen omvang ten onder

Het uitsterven van de Gigantopithecus zo'n 100.000 jaar geleden was een gevolg van zijn gigantische afmetingen waardoor hij zijn dieet niet aan zijn veranderende omgeving wist aan te passen. Dat blijkt uit een nieuwe studie. Met een lengte tot 3 meter en een gewicht tot 540 kilo was de mensaap de grootste primaat die ooit heeft geleefd.

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In a paper published in the open-access journal eLife this week, researchers say they have pinpointed what may well be one of evolution’s greatest copy mess-ups yet: the mutation that allowed our ancient protozoa predecessors to evolve into complex, multi-cellular organisms.

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Op woensdag 3 februari 2016 15:59 schreef Papierversnipperaar het volgende:

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Bijzondere ontdekking: libel vliegt duizenden kilometers

Een libel van nauwelijks drie centimeter lang blijkt de beste langeafstandsvlieger uit het dierenrijk. De ‘wereldzwerver’ legt duizenden kilometers af over de oceaan, van continent tot continent.

3 maart 2016 Paul Heuts

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Tiny Fungus Pioneered Life on Terra Firma

Before primitive ocean-dwellers could crawl out of the primordial sea millions of years ago, there needed to be an ecosystem capable of sustaining them. An ancient, pioneering fungus may have played a key role in transforming Earth’s surface into a life-sustaining ecosystem.

Dr. Martin Smith, now at Durham University, discovered the 440-million-year-old fossilized remains of a stringy fungus belonging to the genus Tortotubus — similar to mushrooms today. The minuscule fossils are believed to be the oldest-known evidence of a land-dwelling organism. Researchers believe Tortotubus helped terraform the earth by decomposing organic matter and collecting nutrients, paving the way for more complex organisms to establish themselves on land.

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A team of scientists unveiled a new tree of life on Monday, a diagram outlining the evolution of all living things. The researchers found that bacteria make up most of life’s branches. And they found that much of that diversity has been waiting in plain sight to be discovered, dwelling in river mud and meadow soils.

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Complex life a billion years earlier than thought?

Researchers said Tuesday they had uncovered fossils showing that complex life on Earth began more than 1.5 billion years ago, nearly a billion years earlier than previously thought. But the evidence, published in Nature Communications, immediately provoked debate, with some scientists hailing it as rock solid, and others saying they were wholly unconvinced.

After first emerging from the primordial soup, life remained primitive and unicellular for billions of years, but some of those cells eventually congregated like clones in a colony. Scientists even took to calling the later part of this period the "boring billion", because evolution seemed to have stalled. But at some point there was another huge leap—arguably second in importance only to the appearance of life itself—towards complex organisms. This transition progressively gave rise to all the plants and animals that have ever existed.

Exactly when multi-cell eukaryotes—organisms in which differentiated cells each contain a membrane-bound nucleus with genetic material—showed up has inflamed scientific passions for many decades. The new study is sure to enrich that tradition.

"Our discovery pushes back nearly one billion years the appearance of macroscopic, multicellular eukaryotes compared to previous research," Maoyan Zhu, a professor at the Nanjing Institute of Geology and Palaeontology, told AFP. The fossils were uncovered in Hebei Province's Yanshan region, where Mao Zedong and his communist army hunkered down during World War II before coming to power.

Zhu and colleagues found 167 measurable fossils, a third of them in one of four regular shapes—an indication of complexity. he largest measured 30 by eight centimetres (12 by three inches). Taken together, they are "compelling evidence for the early evolution of organisms large enough to be visible with the naked eye," said Zhu.

"This totally renews current knowledge on the early history of life."

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Op woensdag 18 mei 2016 14:04 schreef Perrin het volgende:

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Call it a tall task: researchers have decoded the genomes of the giraffe and its closest relative, the okapi. The sequences, published on May 17 in Nature Communications, reveal clues to the age-old mystery of how the giraffe evolved its unusually long neck and legs.

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As the tallest mammals on Earth, giraffes can reach heights up to nearly 6 metres, with necks stretching 2 metres. To prevent fainting when they lower their heads to drink water, giraffes have developed an unusually strong pumping mechanism in their hearts that can maintain a blood pressure 2.5 times greater than that of humans.

[...]

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A clear, internal jelly that helps sharks and other marine animals detect the electrical signals of their prey offers the highest proton conductivity in the natural world, according to a new study.

The jelly in question is found in the 'ampullae of Lorenzini' (AoL) - an array of electrosensory organs present in cartilaginous fish such as sharks, skates, and rays. While scientists have known about the ampullae of Lorenzini for centuries, the remarkable conductivity of the jelly-like substance inside has come as a surprise, and it could even lead to new technological applications for the biological material.

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Getting babies to stop crying and not die may have made humans smarter

With sleepless nights and puzzling crying spells, caring for a newborn may seem like a mind numbing endeavor. But the mental abilities needed to keep a helpless, fussy infant alive may actually be the source of our smarts.

Humans’ extraordinary intellectual abilities may have arisen, in part, in an evolutionary feedback loop involving the care of helpless infants, researchers hypothesize in a study published in the Proceedings of the National Academy of Sciences. In the loop, big-headed babies are born relatively early in their development to ensure that they fit through the human vaginal canal. The underdeveloped newborns then rely heavily on the savviness of their parents for survival. Through generations, this selects for brainy parents, which pushes kids to have ever fatter noggins and, thus, earlier births.