Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: neilep on 26/08/2008 22:45:49

Title: Why Has Cassandra Not Evolved ? ( A sharky question )
Post by: neilep on 26/08/2008 22:45:49
Dearest Peeps Who have Evolved !

See Cassandra here ?


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Nice eh ?..now as far as Great Whites go, I hear she's one hellova babe !

Apparently, ..she's the epitome of her species as she has shown great reluctance to evolve further for the last few  zillion years !!..as a species I admire this lazy attitude to evolve further......

...but why's that then ?...why has Casandra not evolved for such a long time ?..have the oceans really not changed that much in such a long time ?

Are there any other examples of non-evolution over such a great expanse of time ? flora ? fauna ? other ?


As a  sheepy, I of course am also at the pinnacle  of my own species evolutionary ladder !!...Oy !!..I heard ewe think that !...and that !!..how rude !!


Your answers of educational gifts will be most welcome.


Hugs et les shmishes


Neil
Evolved Psychic Sheep

mwah mwah mwah mwah
xxxxxxxxxxxxxxxxxxxxxx

Title: Why Has Cassandra Not Evolved ? ( A sharky question )
Post by: RD on 27/08/2008 11:33:05
why has Casandra not evolved for such a long time ?..have the oceans really not changed that much in such a long time ?

Deep ocean conditions have not changed for eons,  and the laws of hydrodynamics which shaped Casandra are constant.

Quote
Are there any other examples of non-evolution over such a great expanse of time ? flora ? fauna ? other ?
In this thread  (http://www.thenakedscientists.com/forum/index.php?topic=15775.msg191616#msg191616) our not-so-tame creationist Asyncritus has been claiming coelacanths (another deep ocean fish) have not changed in 418Myr.

The phrase "non-evolution" is incorrect: evolution never stops. The form of some creatures who have become ideally adapted to a constant niche may have changed little over millions of years, but evolution has still changed them during this period, e.g. new pathogens will exert an evolutionary pressure on their immune systems. New pathogens are constantly being created by evolution. Those creatures whose immune system can defeat the new virus survive and pass on this immunity to their progeny. Those whose immune system cannot defeat the new virus perish and are an evolutionary dead-end.


So Cassandra's immune system, and possibly brain/behaviour and other systems (e.g. olfaction) will not be the same as her look-a-like fossilized ancestors: evolution has never stopped in her case, or any other species. 
Title: Why Has Cassandra Not Evolved ? ( A sharky question )
Post by: neilep on 27/08/2008 12:43:26
why has Casandra not evolved for such a long time ?..have the oceans really not changed that much in such a long time ?

Deep ocean conditions have not changed for eons,  and the laws of hydrodynamics which shaped Casandra are constant.

Quote
Are there any other examples of non-evolution over such a great expanse of time ? flora ? fauna ? other ?
In this thread  (http://www.thenakedscientists.com/forum/index.php?topic=15775.msg191616#msg191616) our not-so-tame creationist Asyncritus has been claiming coelacanths (another deep ocean fish) have not changed in 418Myr.

The phrase "non-evolution" is incorrect: evolution never stops. The form of some creatures who have become ideally adapted to a constant niche may have changed little over millions of years, but evolution has still changed them during this period, e.g. new pathogens will exert an evolutionary pressure on their immune systems. New pathogens are constantly being created by evolution. Those creatures whose immune system can defeat the new virus survive and pass on this immunity to their progeny. Those whose immune system cannot defeat the new virus perish and are an evolutionary dead-end.


So Cassandra's immune system, and possibly brain/behaviour and other systems (e.g. olfaction) will not be the same as her look-a-like fossilized ancestors: evolution has never stopped in her case, or any other species. 


I am indebted to this wonderful information by RD.

It's also true that sharks donlt get cancer too eh ? could that be an example of inside evoloution?


Many thanks

Neil
Title: Why Has Cassandra Not Evolved ? ( A sharky question )
Post by: RD on 27/08/2008 13:31:40
Sharks do get cancer  (http://web.ncf.ca/bz050/sharksgetcancer.html).

As our resident creationist Asyncritus has correctly pointed out,
 most genetic mutations are either destructive or neutral, only a tiny minority are beneficial (http://www.thenakedscientists.com/forum/index.php?topic=15775.msg191856#msg191856).

Cancer is one of those destructive genetic mutations, which can affect all creatures, (including sharks).
Title: Why Has Cassandra Not Evolved ? ( A sharky question )
Post by: neilep on 28/08/2008 21:37:25
Sharks do get cancer  (http://web.ncf.ca/bz050/sharksgetcancer.html).

As our resident creationist Asyncritus has correctly pointed out,
 most genetic mutations are either destructive or neutral, only a tiny minority are beneficial (http://www.thenakedscientists.com/forum/index.php?topic=15775.msg191856#msg191856).

Cancer is one of those destructive genetic mutations, which can affect all creatures, (including sharks).

Well I guess I won't be doing a Jeff Goldblum with Casandra then !!

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All those years of planning !!..wasted !! [>:(]