My essay on the Post-Human body, now freely available online at Public Philosophy Journal 'The Philosopher' thephilosopher1923.org
Sunday, 3 September 2023
Monday, 12 December 2022
You sure axolotl questions
So I fell down a google hole for a little personal project I started recently on life forms that can regrow and become rejuvenated after serious injury and loss of parts. It's something I got interested in ages ago through reviewing a James Elwick book which detailed the way regeneration was a topic of fascination for biologists in the 19th Century. Apparently Richard Owen, the founder of the Natural History Museum and head honcho biology man in the UK until a certain mr Darwin came along and dethroned him, was particularly enamoured of the problem of explaining why some creatures could grow new bits to replace ones that fell off, and others could not. For Owen the ability of a lobster to regrow a claw, or a lizard to replace its tail, was a central mystery of life and held the key to understanding not only how life works but how to prolong it.
Owen's research program fell into disfavour in the late 19th Century because he never got along very well with Darwinism. I still find his explanation for varying regenerative capacity fascinating though. He theorised that in higher life forms, the vital essence had become centralised in the nervous system, especially the brain, which is why higher forms can only reproduce if they're imbued with 'fecundating principle' A.K.A sperm. Simpler creatures have their life force spread out more evenly throughout their bodies, which is why if a fragment breaks off it can simply regrow. I don't know why this appeals to me so much.
The axolotl is a bit of a poster child for regeneration, because it regrows not only its tail but other limbs and even internal organs.Sea cucumbers get the prize for self-repairing not just comprehensively but rapidly, regrowing lost parts in as little as a week. Hydras outdo their mythological name sake, because any fragment larger than a few hundred epithelial cells that is isolated from the body has the ability to regenerate into a smaller version of the whole. They're also thought to be truly immortal, because they show no processes of senescence -aging. They can just renew indefinitely. A planarian flatworm can also grow back its entire body from a speck of tissue,
One interesting thing is that there is often a key area or body part that must remain intact, in order for regeneration to be viable. We all know (right?) that an earthworm's future depends on where you split it. But did you know that if you cut it after its 13th segment (counting from the head) then it can regrow its head, but not sexual organs? Whereas cutting it between segments 20 and 21 can create two whole new worms? but cut between the 23rd and 55th segments and you'll end up with no worm at all. Mind you, this is just 'red wrigglers', while 'blackworms' will actually self-amputate in response to temperature shifts. And one unfortunate species can be induced to develop a head at both ends.
Why can't humans regrow limbs and organs? The standard modern line would, I think, be that such regenerative powers in a complex multicellular would be too risky, because it would make cancers more dangerous. But this isn't really a complete explanation. Axolotls are pretty complex after all - why doesn't cancer destroy them? Why do some very complex organisms suffer little or no cancer at all? Variable regenerative power could be a product of inherited constraints, frozen into certain lineages by chance.
Makes me wonder if there is any cool scifi imagining humans with axolotl-like abilities. Some superheroes have it, sure, but what if everyone did - how would that change society? It wouold affect our attitude towards risk, presumably. And create interesting new possibilities for body modification.
Right i should really get back to work now.............
Wednesday, 15 September 2021
Day 2 Group selection for Maynard Smith and Sober
So yesterday went really well. To my surprise, i did everything i'd planned! My brain was working, i made some good headway on the talk.
Today - meh. I often find that a good, smart day is followed by a dip. And i didn't even get drunk! I just woke up and couldn't face going back to the notes i'd finished the evening before. It's not the end of the world because i was in and out of EPSA talks and meetings today anyway.
But then this book arrived in the post and has saved me. It's a book that's kind of hard to get hold of. At least, libraries rarely have it, and pdfs don't seem to circulate online, so i had to stump up and buy it. Which is another reason why scholars without much cash - say early career folk who pay for a lot of childcare - are disadvantaged in academia. But i don't have eye-watering childcare costs anymore, so worldofbooks got my money.
It was so worth it! For a random edited collection from 1987, its pretty widely-cited, and now i can see why. Chapter 5 'How to Model Evolution' by John Maynard Smith, and the ensuing back and forth he has with Elliott Sober, is gold.
I think i can build one of my chapters around it (not the one i was meant to be working on, but hey) so i'm going to put my initial thoughts about it down here.
Wednesday, 14 November 2018
Alex Byrne responds
Friday, 9 November 2018
On whether sex is binary
Monday, 17 September 2018
Duck willies
Thursday, 23 November 2017
Autumn days
We are enjoying yet another stunning autumn day here in the North of England - it’s cold but crisp, the light has a wonderful slightly honeyed clarity and the pavements are decorated with delicate origami shapes in an array of purple, yellow and dazzling red. For November 23rd this is highly irregular and I'd personally call it the best autumn in memory. The Forestry Commission predicted as much, back in August, when an unusually wet summer gave trees the opportunity to store plenty of sugars in their leaves. The following months have been almost uniformly dry, warm and still - no frosts to kill off the leaves, no water to turn them into mulch and very little wind to blow them away. The results have been breath taking. Autumn has always been my favourite time of year and the kids are used to me staring at the sky a lot and constantly stuffing fine specimens into my pockets to be pressed and displayed at home, but this year I've been insufferable. By rights it ought to be dark and damp and full-on SAD by now, but its almost December and the skylines are still dripping with iridescent, flaming leaves.
Furthermore, I've just made a thrilling new discovery.
Thursday, 7 April 2016
Ker ching: Putting the Extended Evolutionary Synthesis to the test
Thursday, 31 March 2016
Passing cuddles down the generations (and what else besides?)
Did you know, a mother’s love is so strong that the power of her kiss can be felt many generations after it happens? It is true of rat mother love, at least. In 2004 Michael Meaney's group published the results of a study showing that the nurturing behaviour of a mother rat brings about physical changes in her babies that are subsequently transmitted to grandchildren too. It is a fascinating example of an epigenetic effect – a change that is passed across cellular or organismal generations, even though there is no change to any DNA sequence.
Sunday, 3 January 2016
Brown and Heyes: Social learning and the other cooperation problem
This is the latest in my series of blog posts summarising the talks and responses that took place at the meeting 'Inheritance and cooperation'.
Unfortunately, some idiot forgot to press the 'rec' button on this one (an idiot called 'Clarke'). So i cannot make any audio available I'm afraid : (
Dr Rachael Brown is a Lecturer at Macquarie University in Sydney who has written about learning, its ability to act as an inheritance mechanism and its effects upon evolutionary processes. Her talk, 'Generating benefit: Social learning and the “other” cooperation problem', explored the idea of treating social learning as a cultural inheritance mechanism, and one that occurs, furthermore, in non-human animals.
Monday, 7 September 2015
Birch and Bentley: Time and relatedness in microbes and humans
Friday, 7 August 2015
Powers and Clarke: Insititutions and the development of human sociality
Sunday, 26 July 2015
Merlin and Clark: Extending inheritance
Thursday, 23 July 2015
Helanterä and Uller: Superorganisms as model systems
Helanterä is interested in establishing whether sufficient heritable variation exists at the level of whole insect colonies to support a between-colony selection process, in which colonies act as units of selection in their own right.
Tuesday, 21 July 2015
Inheritance and cooperation: Clarke introducing the themes
Friday, 27 March 2015
Conference Announcement
Inheritance and Cooperation
June 25th & 26th, Balliol College Oxford
Wednesday, 26 November 2014
On the eco-evo-devo of cooperation
Wednesday, 17 September 2014
Kin selection and horizontal gene transfer
Here is a sentence I came across in a paper from the Sterelny/Joyce/Calcott/Fraser collection on Cooperation and its Evolution;
"According to Hamilton's rule, any modification of focal relatedness of genes specifying cooperative behaviors may have an effect on the stability of cooperative behaviors between interacting individuals." (Riboli-Sasco, Taddei and Brown 2013, 281).
I realise the many perils of basing a discussion on a single amputated sentence, but I think it is fair to represent the point being made as the following;
Friday, 11 July 2014
The price of holding a baby
What I adore most about this fact is its utter irreconcilability with all our usual assumptions about why adult animals do things, in terms of fitness maximisation etc. I see nothing a monkey stands to gain from squidging someone else's little 'un (maybe I'm wrong?) except good old-fashioned cuteness.
Babies are just nice. Fact.
Friday, 27 June 2014
In praise of an unkempt garden
There are plenty of houses, in the transitional area of Oxford where I live, whose gardens are what some would call anti-social. Lawns uncut all year, rubble piled up, weeds taking over and generally making the property appear vacant, unloved and unfriendly. At least, this is the typical societal attitude towards such gardens, I think. More careful, considerate homeowners keep everything neat and tidy, which makes the whole street feel safer, keeps house prices higher and generally pleases those inclined towards neighbourhood-watch stickers in their windows. Unkempt houses make a house look empty, which implies no one wants to buy it, which will depress all the prices. Or like it might be occupied by squatters, who are terribly dangerous. Or, worst of all, like students live there.