Category Archives: Channels & Publishers
How to regrow a rainforest – Willie Smits on TED Talks
Willie and the orangs
My Grade 12 class have looked at this story before, and now we can hear about it from Willie Smitts, a primatologist and conservationist who has led a huge project to replant and revive a section on rainforest in Borneo. They have taken over 8,000 hectares of scorched and cleared land and are returning it to a habitat worthy of orang-utans and many more endangered species.
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Smits was featured in TED2009 and here he is with his story of how they regrew the rainforest.
Science and Islam – BBC4 Series
I heard about this series on BBC 4 when listening to the Guardian Science Weekly podcast recently. They had the presenter and physicist, Jim Al-Khalili, on the show talking about some of the great discoveries and advances made in the Islamic world between the 8th and 14th Centuries.
Think about it this way – if it has an ‘al’ at the beginning, there’s a fair bet that it was discovered, invented or pushed forward in the Islamic world: algebra, algorithms, alkali, alcohol…
Alhazen (Ibn al-Haythem) is considered one of the founders of the scientific method which we still use today – a good scientist formulates a hypothesis and devises a method to prove it wrong. In this way, we know if a scientific idea stands up to testing. If not, we need to revise the hypothesis and test again.
You can see the official BBC page for the programme here, but the video may no longer be available to download. Alternatively, pick up the episodes (broken into parts), from YouTube:
1: The Language of Science
Part 1, Part 2, Part 3, Part 4, Part 5, Part 6
2: The Empire of Reason
Part 1, Part 2, Part 3, Part 4, Part 5, Part 6
3: The Power of Doubt
Part 1, Part 2, Part 3, Part 4, Part 5, Part 6
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To find out more about Science and the Islamic world, try some of these resources:
1001 Inventions: a great resource for Science and Tech discoveries
Go there!
Facebook gives you cancer and infantilises the population. Ahem.
“There is no evidence because it would be hard to prove…” Aduh.
BadScience hero Ben Goldacre and Jeremy Paxman take on Baroness Greenfield, The Daily Mail (always a good target) and Aric Sigman in this interview from Newsnight. For a bit of background this is all a response to this story from the Daily Mail: http://www.dailymail.co.uk/health/article-1149207/How-using-Facebook-raise-risk-cancer.html
If you’re in my class, the page you need to comment on is here.
The Daily Mail reports Sigman is claiming (without any real evidence) that time on the computer takes you away from real people. This makes you isolated and lonely and means you are not producing the right hormones and your genes will act up – potentially leading to cancer, immune problems and impaired mental function. That’s a far reach for a newspaper article to be making, but these kind of shock headlines sell papers, or get more traffic on their website.
In this debate we see the importance of peer-reviewed research before making public claims. We see that correlation does not necessarily imply causality and we see that poor reporting of sensitive issues can lead to gross misunderstandings. If we remember, the Daily Mail was central in the reporting of the MMR vaccine scare.
When you watch this interview and read the article, can you think of responses to these questions?
– Are there parts of Sigman and Greenfield’s claims that might sound plausible?
– What kind of evidence would you want to see to support these claims?
– What is the significance of Goldacre’s comment “… you can make anything look dangerous if you are selective in which evidence you quote” ?
– Sigman makes a comment “The paper weas supposed to be a one-sided provocative feature article for The Biologist to make people think more carefully about where society is going.” How does he feel about the media attention that his words have attracted outside this publication?
– Central to Sigman’s claims were that internet use increases social isolation. He had no peer-reviewed work after 1998 to support this, yet Goldacre pointed out all these references that suggest otherwise.
– Sigman tries to re-state ‘social networking’ as a phrase meant for real-life interactions between people rather than internet-based interactions. How has his interpretation of the term led to confusion in the wider public? Who do you think is responsible for this confusion and how could it be rectified?
– Sigman tries to distance himself from the headlines and the conjectures of Greenfield and returns to his concern that internet use is having a direct and negative impact ont the lives of children. Take this opportunity to discuss the benefits and potential negative impacts of the internet with regard to childhood use.
– Goldacre makes a comment that it woudl be bad for research to prioritse what research is done based on the headlines in the newspapers. Do you agree/ disagree? Why?
– How do you think the precautionary principle might relate to the decisions parents make based on this issue?
How would you like to see this story develop? What further research would convince you of the harms or otherwise this debate?
Nature’s YouTube Channel (and some others)
On the heels of the NewScientist YouTube channel we have the offering from Nature. Where NewScientist provides a news-style clip of current Science headlines, Nature’s YouTube channel takes the approach of a video background to articles published in their journal. So far they have ten videos, though they provide useful background to articles such as the Antikythera mechanism, whale evolution and this one on sequencing the platypus genome:
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It’s an encouraging trend to see these journals reach out into internet video publishing – cheap, easy and a great starting place for students getting involved in science. Let’s hope Nature can keep their channel going longer than ScientificAmerican, who started strongly but seem to have given up.
Of course, the bees knees of YouTube channels so far are NationalGeographic, with 847 videos to date. Here’s a gratuitous Great White clip:
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JoVE
Another great channel (though not on YouTube) is the Journal of Visualised Experiments – actually publishing scientific research papers as videos. A good idea, and some really effective videos – especially for letting us see what is going on in the experiment or operation. Unfortunately, their videos can’t be embedded, so get yourself on over there and have a look.
Now comes the question of citing online videos in your work – and here is the answer! (pdf)
Other ‘tube’ resources worth a look are DNAtube and TeacherTube.
Parthenogenesis – Virgin Births in Nature
Happy (belated) Christmas!
How do you really reproduce without sexual reproduction? Asexual reproduction, of course. Simple, really… but not for the females of some species.
There are loads of links in this post, so click on them to learn more.
Parthenogenesis
Some plants, insects, shark and lizard species are known to reproduce by parthenogenesis – embryo development is carried out without fertilisation by a male -so called ‘virgin creations.’
Parthenogenesis can take a range of pathways :
- The egg can be fertilised by a polar body (a ‘leftover’ of egg production), making the chromosome number diploid and triggering embryo development. Here is a simple explanatory animation from amateurmicrography.net.
- Chromosomes in the egg can self-replicate, making up the diploid number and the embryo develops from there.
Other methods include suppression of male genotypes (technically still sexual reproduction?), or eggs cells dividing by meiosis.
The resulting offspring are going to be all the same gender. In some species, the XY system determines gender and parthenogenesis produces all females. In other, the ZW system dictates that they will all be male.
Parthenogenesis is a reproductive strategy that sacrifices the genetic variation (a driving force of evolution) of sexual reproduction for the simple ability to reproduce. Small invertebrates, such as aphids, can use it to produce large numbers of females very quickly.
Komodo Dragons
Larger organisms, such as Komodo dragons (Indonesia link!), have been known to use parthenogenesis in the absence of males, producing an all-male clutch of eggs. It is thought that this might allow them to set up new populations on isolated islands, using just a single female. Here’s a quick video of a Komodo dragon parthenogen hatching:
Some interesting Komodo readers here from Richard Dawkins and Not Exactly Rocket Science.
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Parthenogenesis in sharks
Parthenogenesis has also been observed in captive sharks – the female had no access to males, yet gave birth to live young (though only one, where the normal litter would be larger). Genetic tests confirmed parthenogenesis, rather than the alternative hypothesis of superfecundation (storing sperm for a long period of time). Read the full paper here, and another on hammerheads here. BBC audio explanation here.
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So can it work in us?
Let’s let House MD explain:
In short, no. Not naturally.
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Generally, we use mitosis to replace and repair damaged cells and tissues and for growth and development – filling in the gaps with copied cells. Along the way, our cells differentiate to their function and we end up with a body full of specialised cells – each cell’s structure and biochemistry reflect its function.
We don’t use mitosis for reproduction, as it narrows genetic variation – one of the driving forces of evolution. Instead, when sperm and eggs are produced, meiosis is used – producing daughter cells with half a set of chromosomes. During meiosis, crossing over occurs, giving some recombinants – or ‘mixed up’ chromosomes – leading to some varation. The greatest variation comes from the process of sexual reproduction itself – the gametes – sperm and egg – meet in fertilisation, combining their chromosomes to make a new blastocyst, which becomes an embryo, then a fetus and out pops a baby.
All the offspring of organisms that reproduce sexually carry two copies of each chromosome – one from each parent – and each chromosome carries different alleles – ‘versions’ of each gene. This leads to a great deal of variation and this genetic diversity keeps the the population going.
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What about uses in technology?
Funny you should ask that…
Induced parthenogenesis is being pursued as a method for obtaining embryonic stem cells. Read this New Scientist article to learn more.
The disgraced Korean scientist Hwang Woo-Suk, who shot to infamy after faking stem cell results, was actually and inadvertently pivotal in the use of parthenogenesis as a method to produce human embryonic stem cell lines:
Normally these parthenogenic embryos die after a few days, yet researchers are able to harvest them for stem cells for research. Ethically, these are considered engineered eggs, rather than human embryos. How do you feel about that?
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Questions to think about:
1. How does parthenogenesis differ from binary fission in bacteria, or vegetative reproduction in some plants?
2. How do the XY and ZW gender systems work?
3. How does sexual reproduction lead to genetic variation?
4. What are the costs of parthenogenesis in terms of evolution or resistance to disease?
5. How would the genetic fingerprint of a parthenogen differ from its parent?
6. How would researchers use genetic fingerprinting to determine whether the offspring were parthenogens or were the product of sexual reproduction?
7. What are the ethical considerations of using parthenogenic human ambryonic stem cells?
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References:
Chapman et al. Parthenogenesis in a large-bodied requiem shark, the blacktip <i>Carcharhinus limbatus</i>. Journal of Fish Biology, 2008; 73 (6): 1473 DOI: 10.1111/j.1095-8649.2008.02018.x
Chapman et al. Virgin birth in a hammerhead sharkBiol Lett. 2007 August 22; 3(4): 425–427. Published online 2007 May 22. doi: 10.1098/rsbl.2007.0189.
2000 year-old Greek “computer” recreated
A British curator has recreated an ancient proto-computer, the Antikythera device, based on 2000 year-old salvaged parts, X-ray tomography and huge patience – and got it to work!
As you can see in the NewScientist video, it was an example of a mechanical computer – designed to pr
edict the relative positions of the planets, chart astrology and count down to the Olympics.It shows us just how advanced Greek science was, and makes us wonder – what would have happened if this technology had not been lost? Would the Greeks have been playing Spore in 200AD?
Some questions to think about:
– What makes this a computer?
– What sets it apart from an old alarm clock?
– Where do you think we would be now if this knowledge hadn’t been lost?
The Contraption
Bro Taylor sent another quality video. His title was ‘What Engineers do when they retire‘, though looking at the original website, it should read ‘what workshy engineering graduates do when they don’t want a real job.’
This is kind of contraption that would put Wallace and Gromit to shame:
My favourite quote from their website:”Baynham & Tyers is no longer an active company, as Ben and Tom are heavily involved in exciting new projects.” Like gluing things to the wall, evidently.
Secrets of the Sequence – The Discovery of DNA
This 9-minute clip is an ideal ‘watcher’ to go along with the reader in the Course Companion – it tells the story of the discovery of the DNA double helix structure by Watson and Crick and how their discovery was dependant on the prior work of Rosalind Franklin and the compeitive/cooperative nature of research:
This clip is taken from the vdeo lesson resource provided by Virginia Commonwealth University’s ‘Secrets of the Sequence’ website. They have 50 different videos, each with accompanying lesson plans and activities.
They also have a YouTube channel: VCULifeSciences.
Stem cells used in trachea transplant
Doctors have successfully used stem cells in a rejection-free transplant of a trachea.
This is a great example of internationalism in science – the patient was Colombian, the hospital in Barcelona, stem cells cultivated in Bristol and the final stage of the windpipe construction completed in Milan.
Check your understanding:
Did they grow a new trachea from scratch?
How did they prevent rejection of the tissue?
There is a good short reader on the NewScientist website.
The original research paper was published by The Lancet.
Foldit – help science by playing a game
Foldit is ridiculously addictive. 
It is a protein-folding game/simulation, designed and produced collaboratively between the University of Washington’s Computer Science and Engineering and Biochemistry departments. There is a great introduction to the roles of proteins in metabolism and disease, as well as protein folding, on their about page.
Apart from the great software and in-game tutorials in protein structures, players at the highest level may be contributing to medicine! The University and associated labs are setting problems of protein folding for players to solve – each one an important molecule in its own right and some even the key to curing some diseases.
There is a great article about the game on RichardDawkins.net: ‘Computer game’s high score could earn the Nobel prize in medicine.’ There’s even a classic quote from co-developer Prof. David Baker:
“I imagine that there’s a 12-year-old in Indonesia who can see all this in their head.”
Too right. Let’s represent for Indonesia!
Here’s a quick clip of the game in action at a high level:
Download the game here and get playing!
i-Biology 
