brown@cs.rochester.edu (Chris Brown) (04/08/91)
Jetlag and shift work -induced disorientation are noticeable factors in human performance. I'm wondering if any work has been done on the effects of the twice-yearly switch between standard and daylight-savings times on wildlife. Do the lost and gained hours disturb their alertness or reproductive cycle? The spring switch could be especially bad for birds. Since animals are often more sensitive than we know to even subtle environmental changes, I'm wondering if our messing with their circadian rhythms in this way has had any documented effects. Another example of modern man's insensitivity to Nature? If this topic has received no research, isn't it about time? Of course I realize it's political dynamite. Chris Brown .
vangeldr@cmgm.Stanford.EDU (Russ Van Gelder) (04/09/91)
The human circadian clock free-runs (that is, adopts a period in the absence of time-cues) of about 25 hours - so most people adapt easily to the "fall back", but have a really hard time with "spring forward". This is the same reason most people find it easier to fly west than east. A great suggestion that I heard a few years ago is to make the spring (forward) change "fun Friday". Instead of causing increased sleep-loss by moving the clocks forward on Sunday morning, why not move them forward at 4:00 Friday afternoon? I think most sleep researchers would agree that this is a better time to shift the clock than the middle of the sleep period. Politically I think it would be popular with the working folk, too... Russ
wgpsy471@nmt.edu (Bill Grother) (04/09/91)
In article <1991Apr7.180823.1462@cs.rochester.edu> brown@cs.rochester.edu writes: >Jetlag and shift work -induced disorientation are noticeable factors in human >performance. I'm wondering if any work has been done on the effects of the >twice-yearly switch between standard and daylight-savings times on wildlife. >Do the lost and gained hours disturb their alertness or reproductive cycle? >The spring switch could be especially bad for birds. Since animals are often >more sensitive than we know to even subtle environmental changes, I'm >wondering if our messing with their circadian rhythms in this way >has had any documented effects. > I'm not sure that the DST switch is going to affect wildlife...animals in the wild don't keep track of time [unless the deer are wearing digital watches nowadays] except through the natural day-night cycle and that develops over the lifetime of the animal and is very resistant to small changes. As for lab animals, I imagine that if they are used to having something happen at a particular time each day (feeding, weighing, injections, etc.), a conscientious experimenter will alter the schedule to keep the event at the same time relative to the animals [good experimental technique]. The bottom line is that very few animals are going to become directly affected by us humans changing the clock back and forth by an hour [except for animals such as cows, chickens, pigs, etc., which are found in farms where chores are scheduled to begin at the same time each day]. As a matter of fact, it was the farm lobby which had a big hand in getting daylight savings time so that during the summer, there would be more daylight in the afternoon to allow crops to be harvested, as most normal farm chores are performed in the morning. Bill Grother
minsky@media-lab.MEDIA.MIT.EDU (Marvin Minsky) (04/09/91)
In article <1991Apr7.180823.1462@cs.rochester.edu> brown@cs.rochester.edu writes: >Jetlag and shift work -induced disorientation are noticeable factors >in human performance. I'm wondering if any work has been done on the >effects of the twice-yearly switch between standard and >daylight-savings times on wildlife. Very funny. Another question is whether it is OK for us neo-humans to inhabit the temperate zones. If our ancestors migrated from the tropics a mere few dozen millenia ago, perhaps the changes in season length is bad for us. It's not as though summer and winter are "natural", after all.
cl@lgc.com (Cameron Laird) (04/09/91)
In article <1991Apr7.180823.1462@cs.rochester.edu> brown@cs.rochester.edu writes: >Jetlag and shift work -induced disorientation are noticeable factors in human performance. >I'm wondering if any work has been done on the effects of the twice-yearly switch >between standard and daylight-savings times on wildlife. Do the lost >and gained hours disturb their alertness or reproductive cycle? >The spring switch could be especially bad for birds. >Since animals are often more sensitive than we know to even subtle environmental >changes, I'm wondering if our messing with their circadian rhythms in this way >has had any documented effects. > >Another example of modern man's insensitivity to >Nature? If this topic has received no research, isn't it about time? Of course >I realize it's political dynamite. > >Chris Brown >. France and Japan have both investigated the effects of the switch on schoolchildren. The result was that it's no big deal: students are restless and a bit disturbed the first couple of days after the shift, but nothing is left to de- tect within a week. I agree that there's a lot going on to which we're insensi- tive, but my own conclusion is that there are more important--demonstrably important--issues to pursue. -- Cameron Laird USA 713-579-4613 cl@lgc.com (cl%lgc.com@uunet.uu.net) USA 713-996-8546
w.p.coyne@uk.ac.newcastle (04/10/91)
minsky@media-lab.MEDIA.MIT.EDU (Marvin Minsky) writes: > Another question is whether it is OK for us neo-humans to >inhabit the temperate zones. If our ancestors migrated from the >tropics a mere few dozen millenia ago, perhaps the changes in season >length is bad for us. It's not as though summer and winter are >"natural", after all. Well the time was long enough for them to evolve light skin. (What advantage does a lighter skin give over a darker skin? heat retention?) And talking of skin colour do the esquemoes (sp?) have skin as light as north europeans? Department of Process and Chemical Engineering, + Newcastle University, United Kingdom. + "If we breed like rabbits, + in the long run we have JANET: W.P.Coyne@uk.ac.newcastle + we have to die like UUCP : ...!ukc!newcastle.ac.uk!W.P.Coyne + rabbits" Carlson on ARPA : W.P.Coyne@newcastle.ac.uk + population growth. ................ ................................+.......................
cse223@uk.ac.cov.cck (David Sandiford) (04/11/91)
[stuff deleted] >Well the time was long enough for them to evolve light skin. (What advantage >does a lighter skin give over a darker skin? heat retention?) >And talking of skin colour do the esquemoes (sp?) have skin as light as north >europeans? I heard about an experiment which seemed to show that lighter skin is better at synthesising vitamin D from sunlight.
dag@hp-lsd.COS.HP.COM (David Geiser) (04/16/91)
In :sci.bio, brown@cs.rochester.edu writes:
.
.
b>Another example of modern man's insensitivity to
b>Nature? If this topic has received no research, isn't it about time? Of course
b>I realize it's political dynamite.
I hate DST. The extra hour of daylight burns my lawn.
dag
"in semi-arid Colorado Springs"grayt@Software.Mitel.COM (Tom Gray) (04/17/91)
In article <1991Apr8.180949.19534@medisg.Stanford.EDU> vangeldr@cmgm.Stanford.EDU (Russ Van Gelder) writes: > > > A great suggestion that I heard a few years ago is to make the >spring (forward) change "fun Friday". Instead of causing increased >sleep-loss by moving the clocks forward on Sunday morning, why not >move them forward at 4:00 Friday afternoon? I think most sleep >researchers would agree that this is a better time to shift the clock >than the middle of the sleep period. Politically I think it would be >popular with the working folk, too... > This effect actually happens with shift workers. It may be fun in the spring but working an hour extra in the fall is not. Shift workers have regular shifts in their sleep schedules of about 8 hours. If DST is going to affect productivity, then why wouldn't this show up for shift workers. It always amuses me to hear executives complain of the effects of jet lag. Their shift workers are exepcted to perform normally with 8 hour changes in their schedules every week.