goingtothedo

A question if anyone out there can answer it for me: We humans have colour vision based on three sets of different types of receptor, each sensitive to a different range of light frequencies. Birds demonstrably also have colour vision. Is theirs based on the same method of detection? 1) If so, was theirs and ours evolved separately? Or does it go back to somewhere deep in the roots of the vertebrates? Humans, I assume lost theirs somewhere along the way when our ancestors were nocturnal "shrews", but did we lose it altogether and then have to re-eveolve it? Or did we almost lose it and then recover it? 2) If not, what is the bird method?

Our eyes do not see reality. Our eyes collect rather a specialised set of data which is fed to the brain. The brain then constructs a model giving us useful information on how to interact with the world. There was a test run, quite some years ago where volunteers were fitted with spectacles that inverted their image of the world. i.e. they saw everything upside down. After a few days, their brains adjusted and re-inverted the images so that even with the upside down lenses, they saw the world right side up. And when they took the specs off again, their brains had to relearn how to display their vision. It took a few days again for their normal sense of vision to revert. When someone buys a pair of "varifocal" glasses (i.e. spectacles with varying focal length to allow vision for distance, reading and all in-between), it again takes a few days for the brain to learn how to see through them; typically a couple of days to a couple of weeks. After this learnng period, vision feels "normal" again.

Really? So are they all genetically identical? In effect, clones?

Sorry. Try this http://www.timesonline.co.uk/tol/news/world/europe/article1980396.ece

I think the general agreement on this is that for any individual person, s/he has a top limit to their potential intelligence which is the result of genetic parameters. However, environment and upbringing determines whether and to what extent that potential is fulfilled. i.e. You may be born with the potential to be an Einstein, but if you don't get the early environment to nuture that potential then you probably won't achieve it

I was reading this article in The Times. http://www.timesonline.co.uk/t.....980396.ece It is arguing that human settlement into communities instead of a hunter gatherer existence took place much earlier than originally thought; about 400,000 years earlier. Any opinions on this out there?

Sorry just looked it up and reminded myself what polyploidy is (I've little formal education is this area; just a deep interest and a lot of reading). Yes, it happens particularly in plants doesn't it; multiplication of sections of the genome. So when that arises in an individual, how does it go about breeding? i.e. finding an appropriate partner? Must it multiply vegetatively to produce other individuals to get a compatible match?

Please tell me more

Yes, it is too easy to take a handy mental toolkit and impose that onto the real world out there. I rather liked the tale of the lawyer who argued that evolution could not be true because it would mean that in the transition from one species to another, it would mean that somewhere along the generations, a mother would give rise to an offspring who was not the same species as herself..... Kind of a temporal version of a ring species I suppose

Being pack animals may the reason behind dogs' heart appetites. It's a standard treatment with vets if a dog has seriously lost its appetite to put it in with a group of other dogs as this encourages them to join the scramlbe for the dinner bowls. I've got four dogs and meal times are very short indeed.....

"Species" is kind of a fuzzy term, even Darwin thought so. He went to some considerable lengths in The Origin of Species to spell out that some well qualified parties may consider a particular set of individuals as species and another equally well qualifed consider the same individuals to be varieties of a species or races. His point was that varieties are, to use his phrase "incipient species". Left to go on in the same track they may well become established as fully fledged species incapable of breeding with each other. But should circumstances draw the groups together again they will merge back into one amalgamated species. A better definition of species than individuals that can mate with each other is perhaps individuals who will tend to mate with each other, but even this definition is fraught with rocky shores and wayward currents. In the end, "species" is an artificial term, handy for cataloging, but to be approached with caution who dealing with real living entities.

Hi, i'm new on this forum, so I thought a bit of the kind of thing that interests me might be appropriate. I penned this a couple of years ago on a bitingly cold Christmas night. Christmas on the Doorstep I look above to velvet sky amid the Winter night, Orion rising through the dark, Rigel blue and bright. I see Hunter’s sword where misty birthing stars shine clear, And glowering Betelgeuse, dimly red, marks the dark months of the year. In aged bloated body, the giant’s embers glowing low, Self devoured, consumed within, ashes choking now, The time will come, the spark will fade, pressures no more to be borne, And the giant will blaze in his final incandescent morn. Betelgeuse awaits the day his fires dim and die, When he will burst his iron heart in his final fiery cry, The Red Hand of the Hunter will shed his sundered flesh, In a divine wind suicidal, to nurse his children’s creche. The shattering of his death throes will seed all coming things, Tin, silver and nitrogen, and gold, the gift of kings, Oxygen, uranium, all these he will give, And carbon darkly bright, that his children’s childer might live. The Hunter’s sword in spangled sky shines with birthclouds bright, Full circle round the story comes in gleam of new starlight. “Fiat Lux” says the old tale, but the wonder strikes me through, When from my garden step, at my own back door, I see the birthing of the new. The new stars gleam like diamond dust studded in dusky swirl, And shimmering vapours shroud the stars in glowing, glimmering pearl. We live in a universe of marvels, all there for anyone to find, Needing only open eyes and ears, and more, an open mind. They say we are born of ashes. They say we go to dust. But they never said how this came to be. It irks me and thus, This night I leave the party, to stand amid icy blast, The sound of Jingle Bells and Silent Night from the indoors drifting past. I watch the skies through lucid air, and the birthing stars proclaim The cyclic story, creation’s glory and how the death of others became, The birth of the new, the start of all. Creation’s children are us. Ashes to ashes? But what ashes! We are all born of stardust. As an addendum, "Betelguese", an arabic word translates to mean "the red hand of the hunter".

Rather a nice article by Paul Davies in this week's New Scientist http://www.newscientist.com/ch.....ysics.html Possibly the most extreme version of an anthropic theory I've encountered, but a lot of fun. It revolves around a quantum effect such that a particle may have a "fuzzy" future, and by extension a "fuzzy" past. It extends that to the entire universe and then argues that because we are here to observe it, we are fixing the laws of the universe acquired at the beginning such that a universe suitable for life, and us, is the result. Doubtless there are those of you out there far more able than I to comment intelligently on this. Weird but intriguing.