Verra interestin an convincin airticle by Julia A. Sherman, ‘Evolutionary origin of bipolar disorder-revised:EOBD-R’ in the journal ‘Medical Hypotheses’ (2011). It turns oot that there a connection atween bipolar disorder (whit yist tae be cried manic depression), seasonal affective disorder, an a cauld-adaptit body shape. Aa thir is peened doon tae a certain gene (EOBD-R).
Circadian rhythms in folk wi bipolar disorder is seemilar tae rhythms in beasts that hibernate. Maist intriguin tae me is the norie that the relevant gene cud hae come fae the Neanderthals. It wad been an adaptation tae life in a cauld climate.
… the question is asked, “How could Neandertals survive the winters if they were all depressed? How could they go out to hunt if they were depressed?” … … bipolar individuals have the capacity to switch out of depression during emergencies. … … during the Pleistocene hunting during the winter was often a fruitless, life-threatening activity. Hunters were well advised to save their energy for a better day. Neandertals were known to store dried meat, but as anthropologists have described, during the winters Neandertals did often verge on starvation … The argument of the … hypothesis is that Neandertals would have been even worse off without the bipolar adaptations. Imagine the winter scenario for a group of people, not depressed, living in close quarters for several months. People would become bored and likely to fight over sex partners and food. Some would impulsively venture to the outside never to return. The increased energy expenditures, social conflict, and loss of life seem less adaptive than the scenario of winter depression.
In the mean time the search aye continues for somethin special aboot the modren mind, somethin exceptional tae explain oor predominance an render it inevitable afore the event. At the Gene Expression blog on Discover Magazine, Razib Khan haes been chowin this ower, ever an anon. He questions whether there haes tae be a single 'point mutation' that made wis modren. An e'en gin there is somethin in oor genes that gied us the edge ower the Neanderthals, it michtna come oot in aabody, bit juist in the antrin charismatic leader or aff-the-wa genius. There's interestin discussion in the comments tae his posts an aa, wi a hantle fowk inclinet hae pit it doon tae demography - a creetical mass that allooed the transmeesion o knawledge, specialisation, an organisation.
In contrast tae Khan's thochtfu haunlin o the subjeck, there a gey dire airticle in the New Scientist (staundards haes been faain there for a whilie), 'Different minds' by Kate Ravilious. For maist fowk the story is that Neanderthals had forms o the ilk genes that causes autism an schizophrenia in modrens, genes that's aften associatit wi creativity an lateral thinkin. Some fowk, leukin tae heeze up the Neanderthals, has suggestit that we got thir genes fae the Neanderthals, an sae the Neolithic Revolution is doon tae hybrid vigour efter we mellit wi thaim. For Ravilious on the ither haun - yeukie tae haud doon the Neanderthals - the pynt is that
Neanderthals carried subtly different forms of the AUTS2, CADPS2 and NRG3 genes compared with modern humansWhaur her airticle really faas doon, though, is the suggestion that modren humans war uniquely 'tolerant' o fowk tinged wi mad genius, an sae we cam tae dominate. There isnae a scart o evidence for this, an it sticks in ma thrapple as a blaud o preachy political correctness, shamelessly smearin an opponent as intolerant on the basis o naethin but self-congratulatory sanctimoniousness. Flame aff.