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[Scampi]

Very interesting article on the BBC website about scientists studying post-reproductive orcas to try to work out why menopause has survived evolution.  I don't know how to post a link, but it's in the Magazine section of the News pages.

[CLKD]

We have a thread here already,  keep up Girl, keep up 

[Scampi]

I didn't see the thread.  I still haven't seen the thread and I haven't got time to trawl for it.  I saw the article after a long (11 hour) day at work and thought it might interest some.  I found the 'rolling eyes' 'smiley' upsetting, and certainly won't risk making such a post again.  My apologies for wasting everyone's time. 

[Cazikins]

Hi Scampi,

Don't worry about it, it happens all the time on here & CLKD always, always notices it  .

Lucky for her she has more time than some of us.

And you certainly haven't wasted anyone's time.

Cazi x

[CLKD]

Oh for goodness sake Scampi …….. it would be easy for the threads to be merged  …… so that we all read the same stuff.

Sorry if you feel you have wasted anyone's time, however, did anyone suggest that you had done? 

[dazned]

I think it was obvious CLKD meant it tongue in cheek though,no malice,well thats how I read it anyway .

[CLKD]

I don't have any malice.  Don't have energy for it.

Written word is static …….. ladies here can be fragile. 

Scampi - what else has happened to upset you …………  .  I'm worried why you are upset …….. it wasn't my intention but to save time and energy having 2 threads 

[Cazikins]

Try & be kind & understanding CLKD - don't ask for an explanation as to what else has upset Scampi, it is none of our business - we all have bad days. including you & me.

Members have been supportive of you over the years on here. Your health, mother, anxiety, tummy issues have all been discussed & I hope you have benefitted from the members.

Try & be nice, because I know you can - you do not own this forum, we all are a part of it.

I'm sure you are not really trying to be  malicious as dazned has said, but as you say "Written word is static".

Cazi x

[Hurdity]

Ooer....

Thanks anyway Scampi - this is very interesting!!

Here's the link for anyone who hasn't found it and doesn't have time to Google!!!!:
Brief article:
http://www.bbc.co.uk/news/science-environment-37025088

Actual programme:
http://www.bbc.co.uk/programmes/b07mxv62

I caught the tail end of it on the news the other day and was going to post but saw yours......

Needless to say I haven't had time to listen yet but would be very interested to when I have the time. Did you come away with a any messages Scampi - has the mystery been solved?

I do find the evolutionary concept of menopause difficult to understand except in terms of survival of offspring - if we reproduced right up until our death then those born at the end of our lives would have less chance of survival. However that being the case I would expect us to reproduce up until 15 years or so before we die - but maybe evolution hasn't caught up yet with our artificially induced greatly increased life expectancy - so perhaps we will see the average age of menopause gradually increasing over the next 1000 years (although other factors will come into play before then I expect like running out of oil, climate change, nuclear catastrophe etc!!!).

Well that's my two penn'orth anyway!

Hurdity x

[Scampi]

I got the impression from the article that having a long post-reproductive life is beneficial to the three species that do it (us, orcas and another whale!) as the older females help to care for the young ('it takes a village') - the study also found that the whale pod seemed to rely on the older females to lead them to new feeding grounds when times were hard.  So it appears the 'wisdom' of the post-reproductive females is beneficial to the species as a whole.  As a biologist, I found it very interesting.  It's not so much 'why do we have menopause' - rather 'why do we live beyond reproductive age'.

[CLKD]

>wave Scampi< was thinking of you earlier.  That's interesting, did you read my bit about 'oestrus' in the other thread, maybe you can throw some light on my thoughts 

[Hurdity]

Nice to meet a fellow biologist Scampi - although I should say former in my case, as in I don't now have a profession in any way connected with biol.

What I can't get my head round is the selection process though - for a trait that manifests itself post-reproduction. The way I think I've worked it out is this:

As I said in my previous post below - since infant and young human babies cannot survive on their own there is a clear selective advantage in living long enough to rear them to maturity/independence - so any gene/mutation which meant that women stopped reproducing before they die would confer an advantage and be passed on to their offspring - who would survive longer.

Then you have to postulate an age at which such independence would happen - eg 12 or 15 or something like that.

Having gradually evolved towards this (all these offspring would survive longer so the gene for some sort of menopause would become more numerous), then the gene is being passed on to her offspring and then her grand-offspring which the original mother helps to rear, so that greater survival of all of them would occur not just for the mother/grandmother living 15 years after last child, but a good deal longer - enough to ensure survival of grand-offspring. Presumably this would then mean that the gene - for longer menopause - if inheritance is straightforward - would have been passed on to the grand-offspring ( let's say it's sex linked - my genetics is very rusty...) and therefore become more numerous.

Does that make sense?

Not sure where lifespan comes into play - I'm not sure that lifespan has changed much in evolutionary terms - compared to life-expectancy and a lot more of us are having a longer menopause, because a greater proportion of us are living to our biological lifespan.

I still find it a bit confusing and think my arguments might be a bit circular.

Anyone help me out here?!!

Hurdity x

[Scampi]

Sounds very plausible, Hurdity.  There's an awful lot about the mechanism of evolution and selection that we don't understand, and I doubt we every will!  And I like that uncertainty - I'd hate to live in world where everything is understood.

CLKD - off to look for your post now .... found it - replied 

[CLKD]

 

off to read your reply 

[Kathleen]

Hello ladies.

I'm going out in a minute so I need to be quick lol.

I read the article and listened to the broadcast and they didn't mention the life expectancy of male Orcas although they had observed some individuals dying at thirty. This made me think that if males lived long enough to help the species and thereby provide 'grandad' care perhaps the females would die at the end of their reproductive lives. In other words surely only one member of the species needs to live long enough to confer a genetic advantage, so why females and not males?

K.