Why Do Koalas Have Human Fingerprints?
By Esther Inglis-Arkell | io9.com
Some accuse evolution of being pretty directionless. After all, the whole process involves random genetic mutations. But if evolution is just a toss of a million-sided die, why do so many animals turn out eerily similar? Nope, itís not intelligent design. We take a look at the creepy look-alikes brought on by what biologists call "convergent evolution."
Could a koala frame you for a crime? Probably not you, but it could certainly frame your species. Koala fingerprints and human fingerprints are so alike that experts can mistake one for the other. Which makes no sense, since koalas and humans split off from each other between 125 and 150 million years ago. Our genetics havenít crossed over since (although that would be one cute baby), weíre not the same size, we donít do the same things, and yet the pads of our fingers look exactly alike. How did that happen?
With the emergence of epigenetics, we are getting hints that passing on certain characteristics to oneís offspring may not be entirely random. Lifestyle, stress, and nutrition in the previous generation can play a part in the next generation, and may even shape the species. Still, the heavy lifting of evolution has always been in random genetic mutation. Nature will throw whatever mistakes and quirks happen in the double helix at the wall and see what sticks. Convergent evolution happens because only a certain number of things stick to a certain kind of wall. There are only so many ways to climb a tree, live in desert sands, or go between the sea shore and the ocean. As niches get more specific, more specific methods are needed to fill them, and distinct animals will inevitable evolve specific similarities.
Convergent evolution can be prompted by any set of conditions. White snow brings out white plumage, fur, or scales, in all kinds of unrelated species. Similar predators will chase totally different species into the same trees, or under the same rocks, or force them to fight with the same poison. Any specific food source that isnít already being depleted will bring out similar characteristics in different species. And, of course, much depends on how similar the species are in the first place. This is why placental mammals and marsupials are the poster species for both divergent and then convergent evolution.
When Marsupials Went Away and How They Came Back
Marsupials and placental mammals were identified as different species 125 million years ago, splitting off from a common ancestor via divergent evolution. They seem to have been working their way back towards each other ever since. Marsupials dispense with the last stage of pregnancy and simply give birth to a severely underdeveloped offspring. The baby animal works its way around to a pouch or protected spot on the marsupial and grows from there. Mammals came up with a special thing called the placenta, which nourishes the fetus in the uterus for much longer, and so they give birth to more developed babies. Although we think of marsupials as Australian, since that continent supports the most dominant and diverse marsupials, itís likely that they got there from South America via an iceless Antarctica millions of years ago.
Placental mammals and marsupials found their way with similar genes to similar environments, and converged so spectacularly that theyíve been featured on intelligent design blogs ever since. Some would say that their similarities are more the results of parallel evolution, but considering the distance and the time that separate the animals, and the uncannily similar animals they developed into on separate continents, they do display a gift for convergence.
The flying squirrel has its marsupial equivalent in the flying phalanger. The anteater meets its match in the long-tongued ant-eating numbat. (These not only developed, distinct from other species, lost teeth, developed massive salivary glands, and pumped up their stomachs enough to eat ants. They became the same animal multiple different ways.) Placental mammals and marsupials even fill the same evolutionary nitches. A small forest-living kangaroo in Australia stores fruit by burying it, the way squirrels do in the rest of the world. Since trees with the most kangaroo-or-squirrel-accessible fruit benefit most from this, entire convergent ecosystems spring up. Each pair of animals arenít within over a hundred million years and several oceans of each other, and yet each could pass - on sight - for close relations. But while marsupials and mammals are the most widespread examples of convergent evolution, they arenít the weirdest.
Read the full article at: io9.com
The Ferocious Sabre-Tooth... Marsupial?
íMarsupialí robots could roam Mars and the Moon
Oil spill fingerprinting and nabbing the culprits
Masonic Child Identification Program (takes DNA, dental impression, fingerprints...)
Riddle of missing fingerprints on Dr David Kellyís íoverdoseí pill packs
Polish priest checks fingerprints for mass attendance
Cancer patient held at airport for missing fingerprint
Latest News from our Front Page
Professor: Reason Itself Is A White Male Construct
A philosophy and religion professor at Syracuse University gave an interview to The New York Times Thursday in which he critiqued the notion of pure reason as simply being a “white male Euro-Christian construction.”
Prof. John Caputo was being interviewed by fellow philosophy professor George Yancy for the 13th installment of an interview series Yancy conducts with philosophers regarding racial topics.
Given its emphasis on first principles ...
The Broken Window Fallacy
Youtube description: This short video explains one of the most persistent economic fallacies of our day.
Jenji Kohan and the Jewish Hyper-Sexualization of Western Culture
As detailed in The Culture of Critique, Freud and his followers regarded anti-Semitism was a universal pathology which had its roots in sexual repression. The theoretical basis for this can be found in Freud’s Three Essays on the Theory of Sexuality where he linked aggression to the frustration of human drives — especially the sex drive. Kevin MacDonald notes that: ...
Confederate History - Dispelling the Myths
History books, the media, the school systems, etc abound in falsehoods and inaccuracies of Confederate and Southern history. This fact sheet will help to clarify and dispell some of these rampant inaccuracies.
MYTH - The War of 1861 - 1865 was fought over slavery.
FACT - Terribly untrue. The North fought the war over money. Plain ...
Gays Rights May Open Door for Pedophile Rights
Democrats have attempted to normalize pedophilia as a sexual orientation.
A recent Supreme Court ruling on same-sex marriage may soon allow pedophiles to argue they are suffering discrimination.
‚ÄúUsing the same tactics used by ‚Äėgay‚Äô rights activists, pedophiles have begun to seek similar status arguing their desire for children is a sexual orientation no different than heterosexual or homosexuals,‚ÄĚ writes Jack Minor ...
|More News » |