Posts Tagged ‘Genetics’

Connecting via common ancestors and Genographics – Interview with Wolfgang Haak

// December 8th, 2010 // Comments Off on Connecting via common ancestors and Genographics – Interview with Wolfgang Haak // Recent Research, Science Communication

At the Genographic Event at the RiAus I also interviewed Dr Wolfgang Haak, who spoke about Y-chromosome markers to determine paternal ancestry. He’s been involved in the Genographic Project for three and a half years.

What are the benefits of understanding ancestry?

It’s pretty much a personal thing, at the end of the day, because I suppose everyone’s interested in his or her own genetic history. This is my personal driving force, finding out more about myself. Where’s my place in this planet, in this world, where do I tie into the global picture? That’s a big motivation for me, and as I find out more as I work with people that it’s the same motor or driving force with them as well.

We share a common ancestry after all, there’s a common interest in our genetic history as well.

What first attracted you to the Genographic Project?

I have always been interested in genetics, but I actually come from an anthropologic background and genetics is certainly a part of that. I also come from an Ancient DNA lab. This was a step further into more modern population genetics. This is about getting both things together. Having a modern day perspective, plus adding a timely depth to that picture that we get from modern day diversity.

Tell us about your own ancestry, have you genotyped yourself?

Yes, I’ve done both. Mitochondrial, I’m haplogroup H, and I can further pin that down to group H1, so that is a Palaeolithic, Mesolithic one that might have come into Europe prior to the last glacial maximum, around modern day Spain or Italy or even a South Eastern refuge. It’s not entirely clear but we’ll find out over the next couple of years.

On the paternal side its even more enigmatic. I’m part of a North African lineage that probably originated around the Horn of Africa, so there’s that connection on the Eastern side of Africa where it connects to Saudi Arabia, and that has a high frequency there into the Nile Valley, and from it spreads into South Eastern Europe. Not entirely sure when it spread across the Mediterranean region, but probably historic times rather than prehistoric times.

Genographics, Neanderthals and Cannibalism, an Interview with Carles Lalueza-Fox

// December 8th, 2010 // 1 Comment » // Recent Research, Science Communication, Sex and Reproduction

After the event last night about the worldwide Genographic Project, I caught up with Prof Dr Carles Lalueza‑Fox, the first speaker on the night, for a quick interview. He’s an expert on Neanderthals, or Neandertals I think we call them now. Named after the Neander Valley where the first specimen was discovered.

What first sparked your interest in studying Neandertals?

When the first Neandertal sequence was retrieved in 1997 I had been working on ancient DNA for a while, but then Neandertals seemed to be something in a different league.

In the first ten years it was only possible to get mitochondrial DNA from Neandertals.

For me, I really liked Neandertals and human evolution as a child. Ancient DNA was something particularly difficult at the time, and the thing that brought me to the subject.

How human do you think Neandertals were?

How human?

Yes, tricky question.

Haha, yes. It’s a very long question, a very difficult question. One must always take into mind our tendencies are always fluctuating. We saw them as a very primitive human lineage in the early 20th Century, but I’d say that now we’re turning to the point where we see them as very similar to us.

Maybe the best thing to think about Neandertals is they are more different from us than any modern human to any other modern human. That’s the way we should think about them.

If we want to think of them as a different species that’s fine for me, but there is a range of difference between us and the Neandertals.

The cuts found along Neandertal bones you suggest are evidence for cannibalism. Could they just be an example of de-fleshing prior to burial?

Well, yeah, it might be right in some circumstances. But this is not only cutting, you know de-fleshing the bones. It’s also fragmenting the bones with small stone tools, very small fragments, and even the skull, and the faces. For me it’s very difficult to think that this kind of post mortem activity is something more because this is a complete destruction of the bones.

It’s very similar to what we see in other sites with fauna, the bones are broken to extract the marrow in the same way.

And it’s a pretty common thing, well, not common these days, but certainly we humans have our own history of cannibalism.

Yes, well there are several sites with the signs in Neandertals. But you almost think that life was very tough and they were structured in very small groups, so the fact that you find another one… I mean you’d say “hey, we are Neandertals all of us,” but I’d say that’s a modern conception.

Whereas for them it might be “hey, you’re not one of my family I may as well eat you.”

Yeah, the idea of humankind, in fact, is very recent. After the second World War, and the UNESCO thing. So even the idea of humankind is more recent than we might think now.

And what do you think of the possibility of Neandertals and humans mating?

I think it’s plausible with the data we have. It was probably something that was a minority, restricted in time and space, it was nothing important in my view. The thing is we can detect it now in non-African modern humans is because this was an expanding population, so even a small event of just a few, say it was, this was amplified later on.

The Genographic Project in Adelaide

// December 8th, 2010 // Comments Off on The Genographic Project in Adelaide // Science Communication

The Genographic Project in Adelaide

Last night I was lucky enough to attend the Genographic Project event at the RiAus, where they discussed results of samples collected from the Adelaide public.

The event was a huge success. Every seat was full, and I was fortunate to find a spot tucked in a corner. And that despite the torrential rain that hit earlier in the afternoon, blocking traffic around the city.

One thing that really struck me about the night was the feeling of connection. The billions of humans around today arose from small populations 50,000 years ago. If you start looking back far enough, you share the same ancestral group as the stranger sitting three rows down. In a sense we’re all brothers and sisters.

As more people become involved in the project, we find out more about where and when different groups migrated around the globe. Being involved makes you a piece of the puzzle that will uncover our stories, which have been lost to the past.

Ten years since the Human Genome Project

// June 26th, 2010 // 2 Comments » // How Things Work

Image credit: Russ London

Ten years ago today scientists published the first draft of the Human Genome Project, which aimed to sequence the DNA shared by humans.

This picture is a printout of the human genome in a series of books in London. The 3.4 billion units of DNA code are in more than a hundred volumes, each a thousand pages, in type so small it’s hardly legible. That’s some good reading.

The human genome project was pretty exciting science, hell it still is. A few years ago they thought it would revolutionise medicine, cure cancer, save the world.

It hasn’t been that simple. After all, the amount of DNA we have in common with apes and fruit flies is pretty astounding, knowing the code is not enough. The way the code is read is also crucial, and we don’t understand that very well.

One thing that always interested me was epigenetics, which are non-DNA-coded inherited traits which are passed on through generations. For example how DNA is packaged in the cell determines which parts of the code are read and which are ignored. A heart cell has the same DNA as a hair follicle, but because of epigenetics we don’t have hairy hearts, or hearty heads.

Part of what the human genome project revealed was how little we know about DNA, and how many mysteries are still wrapped up inside us. Nonetheless it was one of the most important projects in human scientific history, and to that let us drink rum!

Meet telomerase, the enzyme that won a Nobel Prize

// February 18th, 2010 // 20 Comments » // Recent Research

As a pirate I am rarely afforded the luxury of meeting the rich and famous, but today I met Elizabeth Blackburn. She was awarded the 2009 Nobel Prize in Physiology or Medicine, making her the first first FEMALE Australian born scientist to win a Nobel Prize. (I also met the PM and Senator Kim Carr, just to round out my VIP day.)

Sadly the story didn’t make the news on TV… further evidence that science just doesn’t rate to the media.

Well, it rates to ME. So I’m dedicating this post to the research that nabbed the Nobel Prize, the discovery of telomerase, builder of telomeres, protector of chromosomes.

WTF is a telomere? Inside your cell you have 46 chromosomes, long strands of DNA that have ends. Chromosomes have telomeres for the same reason we shipfolk dip the ends of rope in wax – so the ends don’t fray. Instead of wax, we have the same sequence of DNA bases (TTAGGG) that repeat over and over and wrap around some special proteins to make a nice neat little end.

When it comes to that special time in a cells life when the mommy cell loves itself very much, it needs to make a copy of all its DNA so it can split into two new cells. Because of how the machinery works it needs some DNA at to hold onto before it can start copying, which means some DNA at each end is lost every time the cell splits. That’s another good reason to have telomeres, you can lose a bit of them each time and it doesn’t hurt your genes.

However you’ve only got a certain amount of telomeres, and once they run out two things can happen. One: the cell stops dividing. Two: Something bad.

Something bad is that the cell, keeps dividing and starts cutting into the rest of its DNA. Suddenly you have lose ends of DNA whipping around the cell like untied ropes in a storm. The cell freaks out and thinks “eep, my DNA strand has been cut! Must sew it back together!” and then attaches one end to another end, probably to another chromosome altogether. That’s actually okay, until it comes time to divide again. The chromosomes need to separate so they can go into the daughter cells, and oh noes they are attached to each other! Solution? Rip them apart, then sew two bits back together… somewhere… Oh dear…

Soon you have DNA that has been stitched together a bit like Frankenstein’s monster. Most of the cells will die (for obvious reasons), but some will survive, will become stronger, better, faster than before, will become the cancer.

So telomeres protect your cells, but usually run out over the life of the cell. Fortunately there’s an enzyme that makes more of those TTAGGG repeats, so you have more telomeres! That’s what Elizabeth Blackburn helped discover – the superdooper trooper enzyme TELOMERASE.

Most of your cells don’t make telomerase, but stem cells do – that’s why they can survive for your whole life. Having an active version of telomerase can help protect against that split/stitch cycle and prevent cancer forming… mice often have more telomerase in their cells, and longer telomeres – as a result they get different kinds of cancers to us.

Pretty nifty enzyme, hey. Don’t know why the media wouldn’t be interested in that… you know, protects against cancer, important part of stem cells… no, don’t put THAT on the news. Let’s have some hardcore sport and a weather feature or two. GORDAMMIT!!!






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