Archive for the ‘Evolution’ Category

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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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Why can’t I have wings?

Tuesday, 1 April, 2008

Dr Samuel Poore, a reconstructive surgeon, has an interesting article in The Journal of Hand Surgery about how to transform a human arm into a bird wing (why that would be a popular idea, I don’t know). Read the write-up at New Scientist if you don’t have journal privileges. He ends up concluding that it is too hard (at least if the wings were intended to facilitate flight), and ends with this advice:

Despite advances in surgical technique that could theoretically lead to the ability to construct wings from arms, it is evident that humans should remain human, staying on the ground pondering and studying the intricacies of flight while letting birds be birds and angels be angels.

Unfortunately, even though I read the whole article, I do not think it is at all ‘evident that humans should remain human’ (emphasis mine). Plus, I don’t want to. Poore provides some good reasons why we can’t yet build working wings out of our arms, but that doesn’t mean we shouldn’t do if we one day can.

There are a few issues that I would raise regarding Poore’s reasons for not being able to give humans any wings:

1. Turning our arms into wings is not what most people would want.

Just look at Archangel from X-Men. Most fictional conceptions of flying humanoids have wings AND arms (except maybe harpies), because arms and hands are just so amazingly useful to human beings that I don’t see why anyone would want to give them up permanently for the mere advantage of flight.

2. What about bat wings? Or pterosaur wings, or even insect wings!

The article is titled ‘ The Morphological Basis of the Arm-to-Wing Transition’, but doesn’t look one of the three historical arm-to-wing transitions – that of the chiropterans (bats). Going down this road would overcome the problem which Poore considers the most difficult – how to give humans the ability to grow feathers. Being mammals, we have a skin structure that probably wouldn’t support feathers (though Poore did not consider the possibility of genetically modifying our skin, so that the areas supporting feathers would have avian-like skin structure). Plus, bats have clawed wings, so by increasing the number of digits on our hand, we might be able to have bat wings and still maintain some sort of ability to pick things up and manipulate objects. I don’t think people would mind looking more like gargoyles rather than angels, would they?

3. Forget about the trabeculae?

Bird, at least the big ones that fly, have rather hollow bones. Mammals have these hollows in their bones too, but not to the dramatic extent that birds do (a bird’s bone has a density of about 0.3g/cm3, whereas a human would average 1.5g/cm3). Bones are mostly air-filled, but reinforced by cross-beams known as trabeculae (Latin for ‘small beams’). This makes the bones of large flying birds extremely light. But Poore overlooks this when he states:

…for a 170-lb human to achieve any type of flight, he or she would need wings with approximately 20 square feet of surface area.

Any person seeking to achieve flight will likely seek hollow bones too, decreasing their weight (though not by much, because bones only represent ~15% of total body mass – so reducing bone weight by 80% will only reduce total body mass by 12%).

If wings are ever to be part of a future human being, the scientists of that age will probably also will look at avian lungs too, which are far more efficient for their size than mammalian lungs. This enables smaller avian lungs to do the same work as big mammalian lungs, will also reduce the weight of the body.

So, why can’t I have wings?
Basically, the reason why humans (probably) can’t ever have any functional wings is that we’re too big.

The power required to flap the wings enough to raise the body is the major roadblock in giving humans wings. Birds, bats and pterosaurs have very large pectoral muscles, (making up about 30-35% of their body mass), which powers their wings. If you think you’ve got enough muscle to flap wings, try doing a push-up and generating enough force to lift your body off the ground and imagine doing that repeatedly. Maybe you just want to glide? Well, lie on your stomach and spread your arms out as far as they can go, and push with your arms enough to raise your chest just off the ground (without bending at your elbows), and hold that position for as long as you can. To glide or fly, you have to use only your arms/wings to hold your entire bodyweight above the ground, such as in the gymnastic position known as the Maltese Cross. The human body is not adapted to this position, and only a few well-muscled gymnasts can hold it for any length of time.

This position is known as the Maltese Cross. You are not even strong enough to glide until you can hold this position.

The addition of the massive chest muscles that a human would require for sustained powered flight would add too much weight, which would necessitate increased wingspan and therefore increase the power needed to fly, thereby requiring more muscles…and so on. There is a point where you simply cannot get any more advantage by adding more muscle mass. But it’s not known what this upper limit is. Existing flying animals don’t get much bigger than 20kg (such as the Great Bustard), but some extinct animals might have been able to fly and were quite large, such as the ~85kg bird Argentavis and the 90-200kg pterosaur Quetzalcoatlus (and both of those animals are predicted to have been mostly soaring animals). Evolution has so far gone through at least three different pathways to sustained flight (birds, bats and pterosaurs), and proven sustained fliers all seem to have very strict constraints on body mass.

So because humans are at least three times heavier than a flying animal should be, maybe the ability for humans to fly will only be possible when we have bionic muscles of super-strength, that are lighter and stronger than biological muscle. Failing that, we could make humans two-thirds smaller. But small humans with large pectoral muscles – they’d look less like fairies and more like…well, birds.

As for wing size, Poore estimates a wing area of 20 square feet (1.85m2) for a 170lb (77kg) human. This seems surprisingly low, as Argentavis weighed about as much as a human but had a wing area of 7m2 (75 square feet) and a wingspan of up to 8m. But Argentavis had a relatively typical wing loading of 11.5kg/m2, and the maximum known for birds is 25kg/m2, so perhaps it could have done some very basic flight with wings half that size. Given his superhuman strength, Archangel’s 4-5m wingspan might be enough, but a better estimate would be almost around 7m for a winged human. But without the necessary pectoral muscles for powered flight, even 7m wings on a person would only be usable for gliding.

Anyway, I’m not saying it is impossible – a gliding human is probably possible (but far easier with a hang glider). But the important thing is, there is no reason I can see of why we shouldn’t try to give humans the ability to fly (and keep them looking mostly like humans). Many humans have wished they could fly, and I don’t see why we couldn’t allow them to grant that wish if it ever becomes possible. There’s nothing morally wrong with granting that wish.

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Darwin Day and it’s relevance

Tuesday, 12 February, 2008

Today marks the 199th anniversary of the birth of one of the 19th centuries most influential naturalists, Charles Darwin. The works of Darwin, like the works of Galileo before him, served to knock humans off another pedestal. Galileo showed that humans were not the centre of the universe, and Darwin’s work showed that humans were not the pinnacle of the biological world. It is perhaps for that reason that evolution of humans is not as accepted as the evolution of animals (despite the fact that since Linnaeus, humans have been part of the animal kingdom). But one’s acceptance of evolution can have consequences for the acceptance of human modification.

The majority of people who do not accept evolution do so for religious reasons. As a result, many choose to believe the more exciting view that humans are not just another ape species but are the divine work of God (some, such as theistic evolutionists, are happy to believe both are true).

The Qu’ran, Surat Al-i-Imran (3:59) tells of the story of the first man, Adam:

Lo! the likeness of Jesus with Allah is as the likeness of Adam. He created him of dust, then He said unto him: Be! and he is”

This is much the same the idea in Genesis 1:27 – that humans are made in the image of God. Therefore, it can be considered to be an unwise move to tamper with the work of a Creator, who is far wiser than any scientist.

Ecclesiastes 7:13 (which incidentally was used in the opening scene of the movie Gattaca) reads:

“Consider the work of God: for who can make that straight, which he hath made crooked?”

If we ignore for the moment the effect this verse may have on the practice of medicine (except for faith healing), it is a nice summary of the idea espoused by many. Humans are the work of God, and a good work at that, and so we can only bring things back to His standard, and cannot make ourselves better.

As is common in the debate of human enhancement, this argument has a secular counterpart among the political Greens and other environmentally minded secularists (whether the Gaians are secular is matter of debate). Basically, it is the argument that the current natural state of humankind is the best we can have.

All of these arguments can be demolished quickly by just accepting (or in the case of the Greens, remembering) that evolution happens. And if humans evolve, and are currently evolving, then any idea of an ‘ideal state’ comes with many problems. If one desires to preserve the current human genome or current human nature, then one must not only work to prevent technological interventions but also the ongoing process of mutation and natural selection that Darwin uncovered (actually, co-uncovered along with Alfred Russell Wallace).

This is summarised by John Harris in his recent work, Enhancing Evolution (p16):

If our ape ancestor had thought about it, she might have taken the view espoused by many of our contemporary gurus, Leon Kass, Michael Sandel, George Annas, Francis Fukuyama, and many others, that there is something special about themselves and that their particular sort of being is not only worth preserving in perpetuity, but that there is a duty to not only ensure that preservation, but to make sure that neither natural selection nor deliberate choice permit the development of any better sort of being.

As we can see, the acceptance of evolution should completely demolish any ‘fetish of a particular evolutionary stage’. However, evolution is not accepted by many people for a variety of reasons, and even if it is, the full consequences of the idea are not recognised. Therefore, doing your part to promote evolutionary theory today (or any other day) will do wonders for the cause of transhumanists around the world.