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Evolution/2 questions of a layman

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QUESTION: 1.   What would be the evolutionary advantage of the human brain to     develop consciousness?
2.   How do species react if they encounter an unfavourable change in their environmental condition, which threatens the population.
  Do they try to increase the population in order to get some to survive or do they defer conception until the environmental conditions get better?

Thank you!

ANSWER:
     
Question:
1.    What would be the evolutionary advantage of the human brain to develop consciousness?

It isn't an advantage to just humans, but to any animal.  Being aware of one's surroundings, by whatever means, increases one's ability to be a better predator, as well as avoiding becoming prey.  All animals are both.  And anything that allows an animal a better chance to survive into adulthood and pass on those good genes, is the goal. All animals are aware of their surroundings, and react to prey/predators in that surrounding.  Self-awareness isn't all that common... humans, most apes monkeys, elephants, dolphins appear to be self aware, and communicate with each other.  Too few tests have been on other species to  state whether they are self aware or not.
2.    How do species react if they encounter an unfavourable change in their environmental condition, which threatens the population.  If the change is slow enough, the species survive, or move,  and as always, mutations are going in each generation.  If it suddenly becomes cold, those with a better coat of hair or fur, will be the ones to survive.  If the cold is a longer process, as the generations pass, only those with a long, thick hair coat will survive.    

If it is a drought, birds with a thicker bill will survive over those with a thinner one, since seeds that are thick survive drought better than those with a thin shell.  Indeed it may be that only plants with thick seeds will be around during the drought.  We've seen this over and over in finches in the Galapagos... and when the drought ends, those hatchlings with a thin bill will again survive, because thin shelled seeds will sprout.  Both  types of bills on these finch, may be in the same clutch of eggs.
  Do they try to increase the population in order to get some to survive or do they defer conception until the environmental conditions get better?  

Neither, as suggested above.

If this does not answer your question, or you need more examples, feel free to write again.

  


---------- FOLLOW-UP ----------

QUESTION: Dear Elisabeth,

thank you for your answer.

I guess my first question aimed more on the concept of self awareness. It would be interesting to know how self awareness could be an advantage in nature. Can you think of an example. I agree very few studies have been done on this field.

Thank you also for your second answer, for an Darwinian like me it is plausible! :-)

But how would this connect to the concept of "delayed implantation"?
Mammals use embryonic diapause to time the birth of their offspring for favourable environmental conditions and sometimes if the conditions are bad there will be no offspring at all.

Thank you again!!

Chris

ANSWER: How is self-awareness and advantage?  We know, for example that those animals that are the most intelligent are animals that live in a society of others, like themselves...chimps, bonobos, dolphins, humans, elephants. And that begs the question, which came first, the self awareness, or the group.  And I don't know that that has been studied in animals.  We do know that in man's early ancestors, communication, and awareness were important to survival of the individual, as well as the group.   And being self aware, as well means a way to communicate with those others in your group, and that their is ranking within the group.  That ranking is known to all within that group. Each animal knows his/her place. And those animals that survive in a group survive better than those which are solitary. And thus self-awareness, and along with it the ability to communicate increases the chances of survival.... the ultimate goal in nature... to survive long enough to pass on one's genes.  Chimps even make war on neighboring groups of other chimps.  Think of all the requirements needed for that type of communication!!!  

I'd suggest "delayed implantation" is somewhat a rare thing.  If there is communication among the group, the group as a whole raises the offspring, in many cases.  I have not read any studies where self awareness was tested with delayed implantation in any significant scale.  If it exists much at all, it isn't a characteristic needed for survival in any great numbers.

Helpful?

---------- FOLLOW-UP ----------

QUESTION: Thank you very much for fully answering my first question regarding self awareness and advantage. That was really helpful!

My second question regarding delayed implantation was directed towards:

How do species react if they encounter an unfavourable change in their environmental condition, which threatens the population (nothing to do with self- awareness)?

I don't think that it is rare as it is used by over 100 different mammals in seven or eight different orders (according to Wiki :-)). It seems to me that in this case some species do react. In Alaska for example if Grizzlies cannot find enough food, delayed implantation results in having only one instead of two offspring or sometimes none.

I do not know if there is an example in nature that could show the opposite.
Please let me know if I'm wrong!

Thank you.
Chris

Answer
I am aware of delayed implantations only in bears, and kangaroos, and if you have found this in 100 mammals, this is still not a huge number in comparison to the number of mammals that actually exist. It obviously helps those mammals who do this, but it is unlikely a large survival tactic...more of a curiosity maybe?

What more commonly happens is that the mother, and fetus simply suffer, thru the pregnancy in lean times...  In  humans, the mother comes out with less bone mass, and the baby may suffer retardation, which if the loss of food is significant after birth, the baby is on the edge of starvation.  Unhappily, this affects it's IQ for the rest of its life. (And sadly, among humans, a child dies of starvation
on this planet every 5 seconds.  Delayed implantation would be
for sure an advantage in African countries, and in any Third
World country.... better the fetus never be born than face a
life of deprivation and lose the chance to become all it could
become.)


If by opposite, you mean that more eggs are produced?  I'm not aware of such a thing.  Only that in "good times" infants of any animal survive better than during times of lean.

Since we do not measure IQ in wild animals, the animal would simply "fail to thrive".  Horses still carry the fetus, as do dogs, cats, and most other mammals, and for sure all primates.

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Elisabeth DeWald

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I've been a public school teacher for 26 years. My major was history, but along the way, picked up minors in math, biology, zoology, and other life sciences. My whole life has been on one side of the desk or the other. Husband and Dad were both MDs so science and medicine was a natural for me. My dad once told me that I knew more medicine than most doctors. I can easily answer almost any life science question, most history questions, and lots of medical questions.

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Taught math,history, science, geology, chemistry, biology in a public school setting

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None at the present time

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none

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Majored in history in college, minored in all those subject mentioned. Masters degree in education. Grad courses, but no degree in religious studies, U of Chicago, Divinity School.

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Award at my one of my colleges of Best Student, in History as a year end award.

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I tutored for two years in math. Math however, if not used daily fades. My area of competency is in honors first year algebra, at this point.

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