Tuesday, February 21, 2017

High-Handed Heterozygotes?

Granted, this paper is from 1981 and the results are somewhat inconclusive, but the premise is still interesting. Jews in particular are a rather interesting population because until recently they tended to only mate within themselves, meaning that genetic drift was rampant (and making them perfect for this study on possible heterozygote advantage in not contracting tuberculosis). Unfortunately, this study found no correlation between the two so having Tay Sachs or being a carrier for it still just sucks.

Art of Science

Voting has opened for the 2017 CNSI Art of Science competition at UCSB. Community voting is open to the entire community.

General info here.

View all the entries and vote for your top five here.

(Full disclosure, Grace is a postdoc in my wife's lab. Her painting is freaking awesome though.)

Ubiquitous cephalopod identified

So, if you, like me, were wondering, what that cephalopod that shows up in all the artist depictions of the Ordovician is, it's probably a member of Orthoceras which is pretty neat. If you want to know pretty much everything about it, I suggest you take a look at this paper, which is pretty dense. And if you just want to read something from the 1930s about fossils in China, check this out. They're proposing a new genus for some fossils that kinda look like Orthoceras. 
Charlie Moffatt

Monday, February 20, 2017

Extinct marine reptile that gave live birth!!!!

*I passed this article around to a couple of you but I thought it might be interesting to everyone*

Baby ‘Sea Monster’ Found Inside Fossil Mother

This article is cool for a couple of reasons. One being that its about a super interesting prehistoric marine reptile with a crazy long neck (which is conveniently depicted in the artist reconstruction painting I have tacked on below. John, that one's for you.) Another being that this 245 million year old marine reptile, which belongs to the same subclass as a number of ancient crocodiles and birds, gave live birth rather than egg birth. Although not the only prehistoric reptile to do so, it is one of few which is really interesting when thinking about the evolutionary pressures and changes that brought marine animals to land and how live birth versus laying eggs could have contributed to that transition.

Who runs the world? GIRLS! --> Female Zebra Shark has babies without mating

Asexual reproduction is nothing new, but a shark switching from sexual to asexual reproduction throughout her lifetime certainly is something to question. Leone, a zebra shark living in at the Reef HQ Aquarium in Australia, gave birth to 3 pups in 2016 after being separated from males since 2012. Christine Dudgeon from the University of Queensland conducted a study to test if Leone had been storing sperm for all these years. Using DNA fingerprinting, Dudgeon found that the pups only had cells from mama Leonie- no DNA was found from any other shark. This is the first time scientists have seen this type of asexual reproduction, known as parthenogenesis. Read this Live Science article and read Dudgeon’s paper to better understand why Leonie the Zebra Shark “don’t need no man” in her reproductive life!!

What actually caused the human bottleneck???

Wait. A super-volcano explosion in present-day Indonesia caused the near extinction of the human population and an extreme bottleneck effect?! Sounds crazy. But maybe that's because it is. Check out this really interesting article from BBC about an Oxford research team that published a paper contesting this theory. They studied tiny glass shards found under tens of meters of sediment in Lake Malawi (just west of where Toba, the super-volcano, was located) and reported finding no changes in composition of the sediment that would indicate a significant enough drop in temperature to induce a "nuclear winter" as is thought to have occurred after the eruption. They suggest that the bottleneck effect observed through genetic studies was from mass migrations out of Africa. Could they be right? Does this theory have it all wrong?


Monday, February 6, 2017

In honor of Darwin day

From Bruce, and in recognition of the fact that Sunday Feb 12 is Darwin Day:

Three things you might not know about Charles Darwin