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Author Topic:   Lions and natural selection
redstang281
Inactive Member


Message 1 of 67 (4134)
02-11-2002 10:52 AM


Instintively a male lion will kill a litter of baby lions if it happens across them. This allows the mother of the cubs to come into heat faster and allows for the murdering male lion to mate with the female sooner. Also it helps insure that the strongest male lion is passing along his genes.
Could someone describe by strickly the means of natural selection how a lion could acquire this trait?
I understand how this trait could continue to exist once it has been aquired, but I am wondering how it could be aquired to start with?

Replies to this message:
 Message 2 by LudvanB, posted 02-11-2002 11:02 AM redstang281 has replied
 Message 11 by joz, posted 02-11-2002 10:27 PM redstang281 has replied
 Message 15 by toff, posted 02-12-2002 7:37 AM redstang281 has replied
 Message 31 by mark24, posted 02-12-2002 11:33 AM redstang281 has replied

LudvanB
Inactive Member


Message 2 of 67 (4135)
02-11-2002 11:02 AM
Reply to: Message 1 by redstang281
02-11-2002 10:52 AM


quote:
Originally posted by redstang281:
Instintively a male lion will kill a litter of baby lions if it happens across them. This allows the mother of the cubs to come into heat faster and allows for the murdering male lion to mate with the female sooner. Also it helps insure that the strongest male lion is passing along his genes.
Could someone describe by strickly the means of natural selection how a lion could acquire this trait?
I understand how this trait could continue to exist once it has been aquired, but I am wondering how it could be aquired to start with?

Hum...somehow,i sense that this is not just academic curiosity...trying to point out that lion now kill the cubs they encounter as a result of man sinning are we perhaps? But to answer your question,all animals have in them the instinctive drive to procreate but that drive is always individual. Meaning,the lion from your exemple does not think in term of his species survival but in terms of HIS survival through his progeny and anything that gets in the way of this is a threat...even other cubs of his own species. If the male wants to procreate and encounters a female with cubs,his natural instinct is to get rid of the cubs of another lion so she'll bear HIS cubs,thus insuring the survival of HIS progeny. As for when this started,it probably did with the advent of life on earth. It is unlikely that there ever was a time when a lion would not have acted this way. Thats the basic tenet of survival through natural selection. Thankfully,humans are not ALWAYS like that...

This message is a reply to:
 Message 1 by redstang281, posted 02-11-2002 10:52 AM redstang281 has replied

Replies to this message:
 Message 3 by redstang281, posted 02-11-2002 11:15 AM LudvanB has replied

redstang281
Inactive Member


Message 3 of 67 (4136)
02-11-2002 11:15 AM
Reply to: Message 2 by LudvanB
02-11-2002 11:02 AM


quote:
Originally posted by LudvanB:
Hum...somehow,i sense that this is not just academic curiosity...trying to point out that lion now kill the cubs they encounter as a result of man sinning are we perhaps?

I suppose it is curiosity to the extent of how well thought out the theory of evolution based on strickly natural selection is. Regardless, I will admit I have my own beliefs, though I have not specifically subjected them in this forum at the moment.
[b] [QUOTE] But to answer your question,all animals have in them the instinctive drive to procreate but that drive is always individual. Meaning,the lion from your exemple does not think in term of his species survival but in terms of HIS survival through his progeny and anything that gets in the way of this is a threat...even other cubs of his own species. If the male wants to procreate and encounters a female with cubs,his natural instinct is to get rid of the cubs of another lion so she'll bear HIS cubs,thus insuring the survival of HIS progeny.
[/b][/QUOTE]
Yeah, this is basically what I was trying to say with my first post. I don't think anyone would disagree with it. It is what we observe and is science, or should I say biology.
[b] [QUOTE] As for when this started,it probably did with the advent of life on earth.
[/b][/QUOTE]
So at some point something had to think up this strategy?
I would consider killing a young to ensure your gene pool is spred a strategy, would you not?
[b] [QUOTE] It is unlikely that there ever was a time when a lion would not have acted this way.
[/b][/QUOTE]
From the entrance of natural selection, I would also agree.

This message is a reply to:
 Message 2 by LudvanB, posted 02-11-2002 11:02 AM LudvanB has replied

Replies to this message:
 Message 4 by LudvanB, posted 02-11-2002 11:56 AM redstang281 has replied

LudvanB
Inactive Member


Message 4 of 67 (4141)
02-11-2002 11:56 AM
Reply to: Message 3 by redstang281
02-11-2002 11:15 AM


I think you are approaching this from a wrong perspective. The lion of your exemple does not elaborate a strategy. He doesn't sit in some corner,thinking about where he's gonna find his next conquest and what he'll do if she happens to have kids. All of what he does is instinctive reactions. Some lions do kill the cubs of prospective mates to facilitate the continuation of their genes but yet other actually adopt the cubs they encounter,though its much more rare. I dont believe that anyone actually thought up this behaviour for lions or any other animals. I believe that it developed on its own when the first creature that was faced with this situation on earth acted this way. From an evolutionary perspective,its conceivable that even microbes did the same at some point before they evolved into more complex(read bigger) life forms

This message is a reply to:
 Message 3 by redstang281, posted 02-11-2002 11:15 AM redstang281 has replied

Replies to this message:
 Message 5 by redstang281, posted 02-11-2002 1:41 PM LudvanB has replied

redstang281
Inactive Member


Message 5 of 67 (4144)
02-11-2002 1:41 PM
Reply to: Message 4 by LudvanB
02-11-2002 11:56 AM


quote:
Originally posted by LudvanB:
I think you are approaching this from a wrong perspective. The lion of your exemple does not elaborate a strategy. He doesn't sit in some corner,thinking about where he's gonna find his next conquest and what he'll do if she happens to have kids. All of what he does is instinctive reactions.

Exactly.
[b] [QUOTE] Some lions do kill the cubs of prospective mates to facilitate the continuation of their genes but yet other actually adopt the cubs they encounter,though its much more rare. I dont believe that anyone actually thought up this behaviour for lions or any other animals.
[/b][/QUOTE]
If you believe no one thought up this behaviour, which I consider a very good strategy, then how did it "evolve?"
[b] [QUOTE] I believe that it developed on its own when the first creature that was faced with this situation on earth acted this way. From an evolutionary perspective,its conceivable that even microbes did the same at some point before they evolved into more complex(read bigger) life forms[/b][/QUOTE]
You see, this is still not an answer to the question. Ok lets consider the very first microbes that acted this way. Now, keep in mind you believe they didn't think up this strategy. How did the microbes develope this behavior? What I want to know is what situation do you believe it was faced with and how did that situation force it's reaction to be this behavior?

This message is a reply to:
 Message 4 by LudvanB, posted 02-11-2002 11:56 AM LudvanB has replied

Replies to this message:
 Message 6 by LudvanB, posted 02-11-2002 2:03 PM redstang281 has replied

LudvanB
Inactive Member


Message 6 of 67 (4145)
02-11-2002 2:03 PM
Reply to: Message 5 by redstang281
02-11-2002 1:41 PM


quote:
Originally posted by redstang281:
You see, this is still not an answer to the question. Ok lets consider the very first microbes that acted this way. Now, keep in mind you believe they didn't think up this strategy. How did the microbes develope this behavior? What I want to know is what situation do you believe it was faced with and how did that situation force it's reaction to be this behavior?

they would have developed this behaviour as a reaction to the situation they faced. Animals will always takes the simplest route to a solution and killing the cubs of a prospective mate is much simpler than going off to atempt to find another mate. Its an instinctive mechanism which can be observed in all animals with very few exceptions. Aside from this,i dont know that you're driving at exactly with this. If you say that you believe that this behaviour was the result of a programation done by God that was then corrupted by man's sin,then i say great...go on believing that. But that belief exists in a compelte void,meaning that its not substanciated by any evidence,either physical,mathematical or otherwise.

This message is a reply to:
 Message 5 by redstang281, posted 02-11-2002 1:41 PM redstang281 has replied

Replies to this message:
 Message 7 by redstang281, posted 02-11-2002 2:26 PM LudvanB has replied

redstang281
Inactive Member


Message 7 of 67 (4146)
02-11-2002 2:26 PM
Reply to: Message 6 by LudvanB
02-11-2002 2:03 PM


quote:
Originally posted by LudvanB:
they would have developed this behaviour as a reaction to the situation they faced. Animals will always takes the simplest route to a solution and killing the cubs of a prospective mate is much simpler than going off to atempt to find another mate.
How'd they know killing off the cubs of a prospective mate would make the mate go into heat faster?
[b] [QUOTE] Its an instinctive mechanism which can be observed in all animals with very few exceptions. [/b][/QUOTE]
I agree. I want to know how it got here by means of natural selection.
[b] [QUOTE] If you say that you believe that this behaviour was the result of a programation done by God that was then corrupted by man's sin,then i say great...go on believing that. But that belief exists in a compelte void,meaning that its not substanciated by any evidence,either physical,mathematical or otherwise.
[/b][/QUOTE]
I was just asking questions about what you would say science is.

This message is a reply to:
 Message 6 by LudvanB, posted 02-11-2002 2:03 PM LudvanB has replied

Replies to this message:
 Message 8 by LudvanB, posted 02-11-2002 2:33 PM redstang281 has replied

LudvanB
Inactive Member


Message 8 of 67 (4147)
02-11-2002 2:33 PM
Reply to: Message 7 by redstang281
02-11-2002 2:26 PM


And i keep answering you...the science,for all we know is that they were faced with the situation at one point and began reacting this way. As to the why they knew,we can only speculate that lions have an instinctive understanding of how female members of their species function,since they share so many common genes. Of course,there might be a whole other set of reasons for it which,i,not being a zoologist by trade,may not be aware of. And yes,there might even be some theological implications here as well...i think we dont know enough to completely rule them out yet but we certainly know enough not to jump to the "goddidit" solution before all other venues have been explored.

This message is a reply to:
 Message 7 by redstang281, posted 02-11-2002 2:26 PM redstang281 has replied

Replies to this message:
 Message 9 by redstang281, posted 02-11-2002 8:16 PM LudvanB has not replied

redstang281
Inactive Member


Message 9 of 67 (4160)
02-11-2002 8:16 PM
Reply to: Message 8 by LudvanB
02-11-2002 2:33 PM


quote:
Originally posted by LudvanB:
And i keep answering you...
I guess you don't understand the question if you think you've answered it already.
[b] [QUOTE] we can only speculate that lions have an instinctive understanding of how female members of their species function,since they share so many common genes. [/b][/QUOTE]
Wow, I wish I had that kind of instinct. It would be great to finally understand women.
At some point in evolution's past this trait would have had to be none existant. If you can believe that life was formed from non living material obviously the instincts had to be non existant at some point. How could this trait of an animal killing the young to promote that animal's genes in the gene pool develope without the trait already existing to begin with? How would genes develope an animals instincts?
[b] [QUOTE] Of course,there might be a whole other set of reasons for it which,i,not being a zoologist by trade,may not be aware of.
[/b][/QUOTE]
So, you don't know? Why are you answering this question then?
[b] [QUOTE] And yes,there might even be some theological implications here as well...i think we dont know enough to completely rule them out yet but we certainly know enough not to jump to the "goddidit" solution before all other venues have been explored.[/b][/QUOTE]
Oh I think this example is evidence of a good design, a program to maintain quality control of an animal.

This message is a reply to:
 Message 8 by LudvanB, posted 02-11-2002 2:33 PM LudvanB has not replied

Replies to this message:
 Message 10 by gene90, posted 02-11-2002 8:27 PM redstang281 has replied

gene90
Member (Idle past 4075 days)
Posts: 1610
Joined: 12-25-2000


Message 10 of 67 (4162)
02-11-2002 8:27 PM
Reply to: Message 9 by redstang281
02-11-2002 8:16 PM


[QUOTE][b]Oh I think this example is evidence of a good design, a program to maintain quality control of an animal.[/QUOTE]
[/b]
You think that the cannibalism of the young and weak so a male lion can satisfy his lust is a Godly design?
Anyhow if that instinct is a product of genetics it's not difficult to see how it could evolve. Crave to eat cubs that don't smell like you and you procreate more, so other lions start practicing infant cannibalism. If a sense of taste is bred into an animal, the mystery vanishes quickly. But how genetics translates into behavior, even in people, is not clear and is the focus of much research.

This message is a reply to:
 Message 9 by redstang281, posted 02-11-2002 8:16 PM redstang281 has replied

Replies to this message:
 Message 16 by redstang281, posted 02-12-2002 9:21 AM gene90 has replied

joz
Inactive Member


Message 11 of 67 (4174)
02-11-2002 10:27 PM
Reply to: Message 1 by redstang281
02-11-2002 10:52 AM


quote:
Originally posted by redstang281:
Instintively a male lion will kill a litter of baby lions if it happens across them. This allows the mother of the cubs to come into heat faster and allows for the murdering male lion to mate with the female sooner. Also it helps insure that the strongest male lion is passing along his genes.
Could someone describe by strickly the means of natural selection how a lion could acquire this trait?
I understand how this trait could continue to exist once it has been aquired, but I am wondering how it could be aquired to start with?

Example:
Generation 1 two lions 2 lioneses.
Lions a and b both breed with lioneses c and d.
lion a eats lion b`s cubs lion b adopts lion a`s cubs.
Generation 2 ten lions ten lioneses.
All 20 are offspring of lion a, if selective infanticide is genetic linked to y chromasome all males exhibit said trait....
Herein endeth the lesson....

This message is a reply to:
 Message 1 by redstang281, posted 02-11-2002 10:52 AM redstang281 has replied

Replies to this message:
 Message 18 by redstang281, posted 02-12-2002 9:32 AM joz has not replied

The Barbarian
Member
Posts: 32
From: Dallas, TX US
Joined: 01-09-2002


Message 12 of 67 (4185)
02-11-2002 11:11 PM


It's not hard to figure out, as suggested above. Male lions who happen to have the habit of killing cubs of other males upon taking over a pride, tend to leave more offspring.
Those who do not, leave fewer offspring. This is sufficient, over a number of generations, to make the practice commonplace.
[This message has been edited by The Barbarian, 02-11-2002]

Replies to this message:
 Message 13 by Peter, posted 02-12-2002 6:14 AM The Barbarian has not replied
 Message 19 by redstang281, posted 02-12-2002 9:35 AM The Barbarian has not replied

Peter
Member (Idle past 1731 days)
Posts: 2161
From: Cambridgeshire, UK.
Joined: 02-05-2002


Message 13 of 67 (4203)
02-12-2002 6:14 AM
Reply to: Message 12 by The Barbarian
02-11-2002 11:11 PM


quote:
Originally posted by The Barbarian:
It's not hard to figure out, as suggested above. Male lions who happen to have the habit of killing cubs of other males upon taking over a pride, tend to leave more offspring.
Those who do not, leave fewer offspring. This is sufficient, over a number of generations, to make the practice commonplace.
Totally agree.
Natural Selection is about competitive advantage in reproducing.
Killing the young of another helps to ensure the survival of the
killer's genes.
If it happens to make the lioness come into heat faster, so be it.
The lion doesn't kill to get the lioness in heat, he kills to reduce
competition for food for his OWN offspring. NOT by thoughtful strategy I'd like to add.
[This message has been edited by The Barbarian, 02-11-2002]


This message is a reply to:
 Message 12 by The Barbarian, posted 02-11-2002 11:11 PM The Barbarian has not replied

Replies to this message:
 Message 14 by Quetzal, posted 02-12-2002 7:36 AM Peter has not replied
 Message 21 by redstang281, posted 02-12-2002 9:45 AM Peter has not replied

Quetzal
Member (Idle past 6124 days)
Posts: 3228
Joined: 01-09-2002


Message 14 of 67 (4209)
02-12-2002 7:36 AM
Reply to: Message 13 by Peter
02-12-2002 6:14 AM


Yep, it's all about differential reproduction. Check out this link . They have a pretty good layman's description of this particular behavior. It's actually an outgrowth of the territorial instinct: since there's so much range competition, any lion who approaches the temporary pride will be attacked (females vs females, males vs males). The pride has a pretty good self-identification. A newly dominant male will not "recognize" the cubs as his, and hence will kill them. It's more or less a side benefit that lionesses come in heat shortly afterwards. I think it's interesting that - if they didn't - lions might be extinct (the average estrus period is two years, or roughly the life expectancy of a dominant male, coupled with the fact that lion reproduction is pretty inefficient. What a life!)

This message is a reply to:
 Message 13 by Peter, posted 02-12-2002 6:14 AM Peter has not replied

Replies to this message:
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toff
Inactive Member


Message 15 of 67 (4210)
02-12-2002 7:37 AM
Reply to: Message 1 by redstang281
02-11-2002 10:52 AM


There have been a number of replies on this post, and it seems to me most of them have missed the boat. The phenomenon of the lion killing the cubs of a 'free' female he encounters is common, but by no means universal in the animal kingdom. It's been observed in chimps, too, but (to my knowledge) that's all.
As to why the lion does it - it doesn't have a reason. It does it because it seems the natural thing to do (to him). Just as (first example that jumps to mind) stalking things upwind of him, rather than downwind of him, seems the natural thing to do. And both behaviours would have developed the same way...some sort of mutation.
Imagine the hypothetical first generation of lions. They don't actually care about cubs, one way or the other. But in one lion, something in his genetic makeup mutates, and to him the natural course of things is to kill all cubs he sees. This doesn't help, as he kills his own cubs, as well...and his particular mutation dies out. But another lion has a slightly different mutation...he thinks it seems natural to kill all cubs he sees except those of lionesses with whom he has recently mated. So he ends up killing all the cubs he comes across who couldn't possibly be his. Coincidentally (as far as he's concerned - it certainly isn't why he does it) this works pretty well as a survival strategy for his genes, since he doesn't let any cubs survive except those that might be his own, and the lionesses he mates with don't 'waste' their time (from his point of view) caring for cubs that can't be his. The result of this is that he produces more offspring than other lions, who don't care at all about cubs, one way or the other. His offspring tend to inherit his mutation, and think killing other lions' cubs is natural, too...and so the trait spreads, until lions with this mutation become the norm...at which time (to be pedantic) it stops being a mutation.
But don't think the lion does it to bring the female into heat, or to stop her wasting her time on other lions' cubs...he just does it because it seems natural to him. An analogy I can think of is catching something thrown at you. If someone throws a ball at your face, you catch it, or knock it away. You don't do the complex differential calculations required to work out the object's parabolic arc in your head; you just instinctively knock it away because that seems the natural thing to do. The lion doesn't weigh up the benefits of killing off the cubs...he just does it, because it seems the natural thing to do.

This message is a reply to:
 Message 1 by redstang281, posted 02-11-2002 10:52 AM redstang281 has replied

Replies to this message:
 Message 25 by redstang281, posted 02-12-2002 10:25 AM toff has not replied

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