Archive for the ‘Science and Politics’ Category

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UK approves experimental genetic engineering of human embryos

Saturday, 6 February, 2016

Good news from the United Kingdom, with the UK Human Fertilisation and Embryology Authority (HFEA) being the world’s first regulatory authority to explicitly approve genetic engineering of human embryos. There are other countries who haven’t banned the technology, but this is the first one to purposefully allow it.

Of course, these won’t be designer babies, as the experiment must cease after the embryos are about 256 cells (about two weeks old). But this is necessary to study the effects of the technology so that maybe one day it will actually be safe enough to use for therapeutic or reproductive purposes. See more about the story in Nature News, Wired and The Guardian.

You can also read some opposition to the decision, with Craig Venter writing in Time and Donna Dickenson in The Telegraph. Both pretty much argue that we don’t yet know enough and should be cautious, and with this I agree. But unless we take the few cautious steps forward by doing the research, we’ll never know enough to be able to edit human genomes. Somehow I think that’s precisely the outcome the opponents want.

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Keeping the brain plastic

Wednesday, 31 March, 2010

Neural plasticity, the capacity for neurons to change their connections, is a fundamental property of the brain. It’s what allows us to learn. But as we age, the plasticity of the brain decreases. Indeed, there are developmental windows called ‘critical periods’ where the brain is especially plastic, usually when very young. The neural basis for vision, as an example, is laid down at during infancy, and doesn’t change easily thereafter. This is why kittens, raised in a visual environment of many vertical stripes, find it difficult as adult cats to see horizontal stripes – their brains, while plastic, had adapted for certain visual features, and found it difficult to adapt to new ones.

Recently, researchers at the University of California San Francisco have found a way to renew the infant-like plasticity of the mouse brain, allowing childlike learning to begin again. They did this by injecting embryonic mouse neurons (not to be confused with embryonic stem cells) into young mice, which had been raised with one eye deprived of light. Without the injection, mice that were deprived up until around a month old (the usual critical period for mouse ocular dominance) would have difficulty adapting to seeing through the eye that had been deprived of light. But with an injection of embryonic neurons into the brain, the mice went through sort of a second critical period, when the injected brain cells were about a month old, thereby aiding the mice to learn to see from their deprived eye.

This has profound consequences for enhancement of human intelligence. The obvious therapeutic outcome would be using embryonic human neurons, taken from human embryos or cultured from human embryonic stem cells, and injecting these into adult humans to give a second chance at a critical period of learning, which would be useful for re-learning to walk after an injury or learning to adapt to blindness (or, I don’t know…learning to control your new cyborg limbs?). But on a grander scale, if we could have a constant trickle of neural stem cells, developing into immature neurons, throughout life, we could very well keep our critical periods going for the rest of our lives, allowing our brains to stay young and malleable!

There is one caveat I can think of. There must be a reason why the brain has evolved to shut off critical periods of learning. Most likely, learning is a costly process in some way, thereby creating a pressure to keep learning periods are short as possible.  If this is merely an increased energy cost, humans in the first world can probably deal with it (seeing as most of us eat too much food energy anyway). But if shutting down mechanisms of learning is necessary for enhancing the function of the newly learned circuits (that is, if we don’t perform as well if we keep ‘changing our minds’), there may be a question of whether learning is worth the cost.

I would assume in this ever changing technological environment and with our lives getting longer and longer (making what we learned during our critical period more and more irrelevant), that keeping the brain plastic would be very useful indeed.

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NIH-funded embryonic stem cell research is now ALMOST legal

Tuesday, 10 March, 2009

I really, really don’t want to rain on anyone’s parade, but you still can’t get federal funding for embryonic stem cell research in the US. But with President Obama signing an executive order yesterday (my time) overturning President Bush’s 2001 statement that banned federal funding for embryo-destructive research, it is one step closer.

It would be good, however, to remember that the ban on federal funding for such research did not orginate with President Bush. The Dickey-Wicker Amendment, which was enacted by Congress in 1996 (during Clinton’s years) and renewed every year since. This law prohibits the US Health and Human Services (of with the National Insitute of Heatlh is a part) from using funding for

(1) the creation of a human embryo or embryos for research purposes; or
(2) research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death

So Obama himself hasn’t pulled down all the barriers, contrary to most uninformed media reports (The New York Times gets it right, though it is a bit unfair on Obama. And scientific journals like Nature, of course, get this right as well). In addition, Obama has not said anything expressly approving federal funding for embryonic stem cell research, so the matter is far from settled legally.

But don’t despair just yet. The removal of the Bush ban on funding this research, and the fact that Obama is supportive of such research, means that when new legislation does appear to permit such funding, President Obama will likely not veto the changes like Bush did (twice).

An important battle has been won, but the war is not over yet. I wouldn’t be celebrating freedom of research just yet.

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Foetal stem cells cause tumours: Irrelevant and obvious

Friday, 20 February, 2009

Too many people overreacting about a recently released story of a boy developing tumours subsequent to being treated by foetal stem cells, grasping onto the case as evidence for the soundness of their moral viewpoint on embryonic stem cells. A typical example is Josephine Quintavalle of Comment on Reproductive Ethics, who is reported to have said:

The risks of tumour formation in association with embryonic stem cells are widely acknowledged and one reason why there are very serious concerns about the proposed use of such cells in treating spinal cord injury in the US. It would appear from this report that foetal stem cells are similarly unstable. These are not areas of therapy we should be rushing into, whatever the ethical debates surrounding the use of embryo or foetal tissue per se.

Notice she just assumed foetal stem cells are the same as embryonic stem cells?

The first objection to this madness is simply that embryos are not foetuses and foetuses are not embryos. The paper in which this case was presented, in the journal PLoS Medicine, clearly states that the “neural stem cells used were derived from fetuses aborted at week 8-12”, and in fact defines the term fetus as “unborn offspring from the end of the 8th week after conception”.  These are not pluripotent embryonic stem cells, sourced from embryos and able to develop into many tissues. The cells used were ‘merely’ multipotent foetal neural stem cells, sourced from foetuses and only able to develop into neural tissues.

Pro-life groups, who rely on misusing words to equivocate babies with single-celled zygotes, are likely to continue making this mistake. Strangest of all, they should not be opposed to foetal stem cells, as they are sourced from abortions that would have happened anyway. In this sense, they are similar to the embryonic stem cells sourced from otherwise discarded leftover IVF embryos. Better they be used as a cure rather than be binned and incinerated, right? So, this case, while unfortunate, is irrelevant to whether embryonic stem cells should be used.

Secondly, cancer is a risk present with all stem cells (and indeed all cells). After all, stem cells are, by definition, able to proliferate – to grow and mitotically divide – many times. As a consequence, it only takes a single mutation to some aspect of growth regulation for a stem cell to become a tumour. For a normal cell to become cancerous, it must gain the ability to proliferate in addition to a lack of regulation. This has been known for ages, and is reviewed well by Michael Clarke and Michael Becker in Scientific American and, more technically, by Michael Clarke and Margeret Fuller in the journal Cell. All stem cells pose a risk of turning cancerous, regardless of whether they are adult stem cells, embryonic stem cells, or a somatic cell induced into pluripotency.

Embryonic stem cells, foetal stem cells and induced pluripotent stem cells carry such high risk of cancer for the same reason that makes them have such great potential for repairing tissue and curing disease. While adult stem cells can divide many times, only embryonic stem cells (or similar) can divide almost indefinitely.The restricted lifespan of adult stem cells make them less likely to form a tumour, but also means they have less time to repair the tissue. Preferring stem cells for this reason is rather like preferring to hire elderly people to be spies because they likely to retire or die before they go rogue or are turned into being a double agent.

Unfortunately, all current stem cell therapies with the promise of embryonic stem cells also carry the elevated risk of cancer.  So this case of a boy developing tumours from stem cell therapy, while unfortunate, was obviously going to happen to someone.

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Significant minority favour designer babies

Wednesday, 28 January, 2009

The results of a recent study into public opinion on reproductive genetics (reprogenetics) have been released. It’s promising, as the percentage of respondents who would consider using genetic testing to select for a child with increased athleticism or intelligence was in the double digits (10 and 12.6% respectively). In addition, the majority of respondents (52.2%) also said that there was no form of genetic testing that should be always off limits, meaning that genetic enhancement may be considered allowable if it was to be voted upon.

That said, the respondents were people who were visiting a genetic counsellor, and therefore the results may contain some bias towards acceptance of genetic testing or genetic enhancement.

For a longer and more in-depth analysis, read what George Dvorsky had to say on it.

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Why we should resurrect Neanderthals

Monday, 10 November, 2008

The recent announcement that scientists had cloned a mouse that had been dead and frozen for 16 years has been raised hope that extinct species may be cloned and brought back to life ála Jurassic Park. The first species on the agenda is currently the woolly mammoth, but being that I love ethically troubling science, I say the first species we should be aiming to bring back are our long-lost brothers and sisters, the Neanderthals. While these may not be found frozen any time soon, enough DNA is considered to be potentially available that the Max Planck Institute for Evolutionary Anthropology, in partnership with 454 Life Sciences, has been working on sequencing the full genome for Neanderthals. Once complete, it would clearly be possible (though maybe not technically feasible as yet) to construct a physical Neanderthal nucleus, and from that produce a living Neanderthal (who would need to grow up from baby to adult, of course).

Neanderthals are an extinct species of hominin, which were driven to extinction some time around 20-25,000 years ago. Modern humans, Homo sapiens, and Neanderthals, Homo neanderthalensis, are generally accepted to be sister species, evolving from a speciation (splitting of one species into two) of the our common ancestor between 150,000-350,000 years ago. The speciation event can’t be pinned to any specific year, as interbreeding between the two species may have occurred for many millenia, and may have always been possible.

Neanderthals, also physically distinct enough to be classed as a separate species, would still very similar to modern humans. Francisco Ayala and Camilo Cela-Conde write of the difference between Neanderthals and humans:

“If we leave behind last century’s romantic view of Neanderthals as brutes, clumsy and deformed, and instead we dressed them up in any of our neighbor’s clothes, would we pick a Neanderthal out among a group of human beings? Maybe not. But would that make him one of us?” Ayala and Cela-Conde (2007), Human Evolution, Oxford University Press, p 314

Such ‘romantic’ view of another species are hardly surprising, given the common caricature of even other races within our species as brutish simpletons. While racism may be on its death bed, and we would think it horrid to insult somebody by calling them a ‘Nigger’, speciesism is still as rife as ever, and we would hardly think it especially offensive to denigrate another with the label ‘Neanderthal’.

And this is the reason why I think Neanderthals should be brought back. Currently, we have expanded the circle of protection from ourselves to others of our group and then to strangers outside our group (other races, other religions), and will continue to expand it (as Peter Singer, borrowing from W.H. Lecky, has argued). But I don’t think we will ever see unanimous equality between species until we actually can see another species similar enough to humans for this species barrier of ethics to be broken down.

It is a well known effect that discrimination decreases as diversity increases, but currently we have no diversity among our genus. We modern humans are the only species in our genus, so it is then hardly surprising that many humans are extremely intolerant and bigoted towards other species. What would their reaction be, then, when confronted with a young Neanderthal child? Will they consider the child to be less than human for not belonging to the superior species, just as a girl child was in the past considered a lesser human for belonging to the superior gender? Or will they realise that their species is not superior, and that other species are their moral equals.

Evidence suggests that Neanderthals had culture, religion, art and, vitally, language. A key factor in removing any bigotry is for the group being discriminated against to be able to speak out against such behaviour (noting that the ability to speak vocally is not required, as deaf and dumb humans would no doubt have me emphasize). Therefore, it seems likely that Neanderthals will be in the best position to argue against speciesism, being a member of another species.

There are three common argument for humans to have rights. First is that human are unique, exceptional among other life forms, and (sometimes) the sacred creation of a divine being. And, this argument goes, any human being is therefore deserving of rights just for being human. As I’ve argued previously, this argument is blatant bigotry, and therefore combating this viewpoint is one important reason for bringing Neanderthals back*.

Second, a being is said to deserve rights if it can understand the concept of responsibility. Of course, this doesn’t let humans infants have any rights, so these people usually just fall back on the above mentioned view, and say that it is enough to be a member of a species with the concept of responsibility (why species? why not genus, or family?). Anyway, it appears that this will be a moot point, as it would be likely that Neanderthals would have had some concept of moral responsibility if they had language and formed groups with religions and cultural traditions.

adult_male_neanderthalLastly, and the view I favour, is that rights are political representations of our responsibility towards other autonomous sentient beings. If a being is capable of valuing its life, it can then consent to life or death, and therefore only with this consent can its life be permanently and irreversibly ended. From this, therefore, I conclude that this being has a right to life. Likewise if a being is capable of valuing being free of pain, we give a right to not be tortured or suffer unnecessarily. Under this viewpoint, not only would Neanderthals have almost all the rights of humans, but many of these rights could also be extended to other animals, especially the great apes.

It may be, then, that speciesism will always remain, or at least until we can develop human-level artificial intelligence or encounter human-level alien life. But even without this moral imperative seeming likely to be successful, the field of evolutionary anthropology would be accelerated tremendously by examining the difference between Neanderthals and humans.

By the way, for a fictional account of this, I have been made aware that a series of novels by Jasper Fforde has mention of bringing Neanderthals back via science, and the subsequent Neanderthal rights movement.

*A minor group of scientists is of the opinion that Neanderthals are merely a sub-species of humans, Homo sapiens neanderthalensis (with us being in the sub-species Homo sapiens sapiens). With a living Neanderthal to examine, their viewpoint might be pushed – for emotional reasons – into popular acceptance, or even be found to be true. This would undermine any efforts to combat speciesism, as it would merely pull Neanderthals into the circle of our species rather than move the circle out to take in another species. To count this, I’d suggest cloning other species of genus Homo, such as our direct ancestors H. erectus or H. heidelbergensis, but the relatively recent demise of the Neanderthals makes gathering the requisite DNA much more feasible, and the similarities between Neanderthals and modern humans are enough to make it more likely that we would end up accepting Neanderthals as persons, if not as fellow human beings.

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Mice reject human embryonic cells – so what?

Friday, 22 August, 2008

Researchers at Stanford University School of Medicine found that mice mounted an immune response after being injected with human embryonic stem cells (hESCs). The result: all the transplanted stem cells—which hold the promise of maturing into several different types of tissue—were dead within a week [from Scientific American].

All of this is leading many to claim that embryonic stem cells won’t work. But that is is big stretch from the data in that study.

First, this study examined human cells implanted into mice. Mice are not the same as humans. The genetic difference there is obviously going to be a factor. That said, it is true that mice have also rejected murine embryonic stem cells (Wu et al 2008), but some research has shown that mice are more likely to develop a tolerance to embryonic cells than to other transplanted tissues (Robertson et al 2007).

Second, scientists already thought this would happen. It is for that reason that the whole concept of therapeutic cloning was considered. If the embryonic cells were genetically identical to the patient, the immune system would likely not attack those cells.

That said, therapeutic cloning still leaves the 16 genes that are present in the egg donor’s mitochondria. It is possible (though, considering that these genes are not cell-surface proteins, unlikely) that this slight difference could still cause an immune response. This has lead some to tout induced pluripotent stem cells as an answer, but those cells are genetically modified in order to induce their pluripotency, so not even they are identical.

I think that both therapeutic cloning and induced pluripotency will be solutions to this immune problem, although I personally would favour the genetic modification of the immune system to stop it being so reckless and killing that which is trying to help. After all, those of us who suffer from autoimmune diseases know that the immune system can quite easily attack cells which are genetically identical to all your other cells.