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Nathan Pieplow
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Nathan Pieplow

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A successful land war in Asia: the DNA evidence

Linguists have long suggested that a wave of invaders swept across Europe and Asia several thousand years ago, probably starting from somewhere in the Black Sea region.  Spreading out in all directions, these people brought the new technology of farming with them, and a new language called "proto-Indo-European."  Over the centuries, this language split and diversified into Spanish, Hindi, Russian, Farsi, Gaelic, and many other modern languages, including the one you're reading right now.

What happened when these invading cultures clashed with the pre-existing ones?  Did they kill everyone?  Drive them away?  Or settle down and intermarry with them?

DNA sequencing provides new evidence for an answer.  By comparing the genetics of 39 skeletons buried in the same region of Germany at different times in the past 40,000 years, researchers found a sudden switch from one set of gene types to another, associated with the switch from a hunting-and-gathering culture to a farming lifestyle.  In other words, it looks like the "settling down and intermarrying" theory can be largely ruled out, at least in this area of Germany.  (Personally, I suspect there were lots of spears and swords involved.)

Not all remnants of the earlier cultures are gone, however.  Modern Finns, Hungarians, and Estonians speak languages related to one another, but not to the Indo-European group.  Their ancestors likely survived the invasion of the farmers, whether by fighting them off or by making peace with them.  But even these people may have been invaders once: the Basque people of northern Spain and southern France speak a language with no known connection to any other surviving tongue.  They could be the sole survivors of the invasion before last. 

And before the Basques?  Who knows?  The languages are now silent.  But perhaps DNA will one day provide an answer.
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Only have two hands? Blame Euphanerops.
A looong time before anybody crawled out of the water, fish got into an evolutionary "arms race" (ha!). Some of them were evolving jaws and teeth, the better to eat each other with. Perhaps in response to these new weapons (or to take full advantage of them), some fish were also evolving fins in pairs, which apparently increased their speed and agility. Those fins would one day form the basis for the body plan of all land vertebrates... including us.
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Right side male, left side female

In the face of modern political arguments that certain types of people or behaviors are "not natural," it's well worth remembering that nature entertains far more possibilities than some people do.

When the two sides of your body are different sexes, you're called a bilateral gynandromorph. For reasons we don't fully understand, this happens fairly frequently in some groups of animals, especially butterflies and birds.

Here's one way it can happen.  In many organisms (including humans and butterflies), the "Y" chromosome is what makes an organism male. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).

Right before a cell divides, it copies all its chromosomes.  Male cells at this stage are temporarily XXYY.  One Y chromosome is supposed to end up in each daughter cell, but if both of them land in the same cell, that cell will be male and the other daughter cell will be female. If this happens at an early stage of development of a male embryo, it can cause half of the entire organism to become female.

At least in butterflies, more complex patterns of male/female combinations are also possible.  This is called "mosaic gynandromorphy."

The post below is old, but well worth resharing. +finch wench put together what appears to be the internet's largest collection of photos of gynandromorphic birds.  How do these birds act?  Of one bird, it was written, "he sang in courtship ritual and was reported to be hostile with the male suitors of his left side."

In nature, almost anything is possible.
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7 sexes, 21 combinations!
The sex life of this microscopic protozoan is wild. It has seven different "mating types," or sexes, that can reproduce in any of 21 combinations. Any combination can produce offspring of any of the sexes.  New research shows that after fertilization, the offspring cell genetically "chooses" its sex at random.

Original study: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001518
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The mystery of the deformed bird beaks
In 1991, a Black-capped Chickadee with a grossly deformed beak came to a backyard birdfeeder in southern Alaska.  People thought it was an unfortunate, isolated case of a bird developing improperly.

It wasn't.  It was the start of a regionwide crisis.

Today researchers estimate that up to 7% of all Black-capped Chickadees and up to 17% of crows in southern Alaska have deformed beaks.  Over 30 other species are also affected.  The problem has reached "epizootic" proportions (that's what you call an epidemic when it occurs in animals).  For the past 14 years, researchers have doggedly pursued the causes of the phenomenon, seeking links with malnutrition, disease, parasites, genetics, and a variety of possible pollutants including heavy metals, pesticides, and PCBs.  They've considered the possibility of contaminants riding air currents from East Asia to Alaska.  So far, there's still no explanation.

Whatever the cause, the malady makes it difficult for afflicted birds to feed themselves.  And whatever it is, it seems to be spreading. It may now be affecting crows and hawks as far south as Seattle.  The Alaska Science Center has set up a webpage where you can learn about the latest research and help document the extent of the problem.

#ScienceSunday
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The same malaise is happening in our oceans. It's not really a surprise that it should happen to the air as well.
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Have him in circles
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Nathan Pieplow

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Would love to discuss this on Sunday.  There's been some controversy about whether these "hobbits" are really a separate evolutionary branch of the human family tree, or merely humans suffering from a condition called microcephaly.  A new study is being spun as another piece of evidence for the former conclusion.
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Sounds good to me!
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Tudor warship Mary Rose and her evocative contents going on permanent display in Portsmouth in May
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Are You Interested In Discussing Science, and Science in the News, In Hangout?

We want to engage the public on a weekly discussion show, to start soon. You do not need to have a science background, but if you want to participate, you will need to be willing to read 5-10 science articles put up in a shared Google Drive document weekly. We will go through these topics as we discuss them live on hangout. The show will run for about an hour a week. If you are a panelist, you do not need to attend every week, but the weeks it fits your schedule. 

The benefits to you for participating on the show will be exposure for the things you participate in. We ask  that you have a good solid grasp of science basics; but please don't feel like it will be a quiz or test of your knowledge. We are trying to engage the public during these hangouts as well as just open it up to some basic questions and see what we can answer.  

 If you work or study in a science related field, we would also be delighted to have you participate as well. This is an outreach experiment we are trying. Our first show would be set to air in about 3 weeks. 

If you are interested, please comment below and we'll send you a message to set up a private hangout. Please don't be intimidated! We would love to talk with you and facilitate communication. Part of the issue with science communication is that it's often seen as cut off from the public. We feel opening dialog about the process can only lead to greater understanding, so this hangout experiment might help in that regard. We'd also like to end each show with a recommendation of a non-fiction book in the sciences which we think is a good read.

The format of the show is meant to be friendly, fun, and accessible. Let us know if you have any thoughts on the matter. 
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Nathan Pieplow

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Using audio recordings to travel back in time.
 
Voices from the Past: Recordings of Extinct Birds
My favorite is the 1954 recording of the elderly Maori man who remembered the song of the extinct Huia from his youth, and was able to whistle it into the microphone for the New Zealand Broadcasting. Reblogging an old post, inspired by today's news about Pacific bird extinctions: http://news.sciencemag.org/sciencenow/2013/03/scientists-gauge-ancient-die-off.html?ref=hp
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What happens when you save the wrong species
Biologists thought Colorado's state fish, the Greenback Cutthroat Trout, was on the road to recovery, with reintroduced populations doing well throughout their former range in northeast Colorado. But DNA analysis now shows that, due to attempts to save them by restocking, those fish actually aren't greenbacks at all -- they are hybrids with Colorado River cutthroat trout.

Since 1889, fish hatcheries have been raising what they thought were greenbacks in captivity and releasing them into streams where native greenbacks persisted, in order to bolster the wild populations.  At first this was done for the benefit of fishermen; later it was done for the benefit of the fish populations themselves. Only problem is, the fish being released into the stream were misidentified. Now they've interbred with the native populations, and no pure-blooded greenbacks remain in any of these restocked streams.

Luckily, one pristine population of the original fish does survive, and ironically, that's the fault of sloppy re-stocking efforts too.  In the 1880s, a hotel owner who wanted to attract fishermen to his inn near Pikes Peak stocked some greenbacks into his local stream, Bear Creek, which is outside the species' original range. There's no word on whether his gambit earned him business, but the stream was so small and remote that it escaped further fish stocking for 130 years, and now holds the only living greenback cutthroat trout whose DNA matches that of the museum specimens preserved in alcohol in the 19th century.

The hybrid populations of "greenback" cutthroats in northern Colorado are likely to be renamed. The real greenback cutthroat is now apparently critically endangered, with an estimated 750 individuals surviving.
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