Evolutionary news
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A well reasoned proposal Freethinker. No dogma, no following of what others want us to accept. But I find one objection to it, as you mentioned, we appear to be the only species to have taken the big brain route to avoid extinction. The supposed climate change pressure afflicted other species besides our own, so why have they not developed bigger brains?
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FreeThinker
- Posts: 91
- Joined: Mon Apr 03, 2006 7:35 pm
Big Brain and Other Species
Different species will evolve in response to the same changing environmental pressures in different ways. Some might not even change at all. This is because all species fill seperate niches and thier ability to survive in whatever niche they occupy relies on different adaptaions in each species.
A hypothetical example of this could be in the case of a drying of the climate. A snail species might grow a different shape shell that would allow less water evaporate by covering more exposed flesh. The earlier snails from the wetter climate era lacking this adaptation would not be able to survive in this new, drier environment. Over the same period of time in the same drying environment a species of fishing birds might see its source of food dwindle and dissapear and be forced to diversify and ultimately adopt a totally new food source, lets say lizards. Long spindly wading legs might shorten and grow stouter into running legs and a long beak ideal for catching fish might shorten and hook for better strength and grasping. Another species like ants might not have their niche disrupted at all and therefore remain basically unchanged. These three hypothetical examples I hope illustrate how each species might evolve different adaptaions to overcome the same environmental pressure brought on by a drying climate.
Perhaps a hominid species might evolve a bigger brain to answer the challenges presented by the new drier climate. Whatever the real incubating environmental pressures were they ultimately resulted in us and only us evolving our sophisticated brains. What I find perplexing is why has no prior species in all the long history of evolution developed a sophisticated intelligent brain. Some unique convergence of adaptations and environmental pressures allowed us to fill a niche only our species to date has filled.
A hypothetical example of this could be in the case of a drying of the climate. A snail species might grow a different shape shell that would allow less water evaporate by covering more exposed flesh. The earlier snails from the wetter climate era lacking this adaptation would not be able to survive in this new, drier environment. Over the same period of time in the same drying environment a species of fishing birds might see its source of food dwindle and dissapear and be forced to diversify and ultimately adopt a totally new food source, lets say lizards. Long spindly wading legs might shorten and grow stouter into running legs and a long beak ideal for catching fish might shorten and hook for better strength and grasping. Another species like ants might not have their niche disrupted at all and therefore remain basically unchanged. These three hypothetical examples I hope illustrate how each species might evolve different adaptaions to overcome the same environmental pressure brought on by a drying climate.
Perhaps a hominid species might evolve a bigger brain to answer the challenges presented by the new drier climate. Whatever the real incubating environmental pressures were they ultimately resulted in us and only us evolving our sophisticated brains. What I find perplexing is why has no prior species in all the long history of evolution developed a sophisticated intelligent brain. Some unique convergence of adaptations and environmental pressures allowed us to fill a niche only our species to date has filled.
Science: the PROOF shall set you free
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FreeThinker
- Posts: 91
- Joined: Mon Apr 03, 2006 7:35 pm
Big Brain and Other Species
Different species will evolve in response to the same changing environmental pressures in different ways. Some might not even change at all. This is because all species fill seperate niches and thier ability to survive in whatever niche they occupy relies on different adaptaions in each species.
A hypothetical example of this could be in the case of a drying of the climate. A snail species might grow a different shape shell that would allow less water evaporate by covering more exposed flesh. The earlier snails from the wetter climate era lacking this adaptation would not be able to survive in this new, drier environment. Over the same period of time in the same drying environment a species of fishing birds might see its source of food dwindle and dissapear and be forced to diversify and ultimately adopt a totally new food source, lets say lizards. Long spindly wading legs might shorten and grow stouter into running legs and a long beak ideal for catching fish might shorten and hook for better strength and grasping. Another species like ants might not have their niche disrupted at all and therefore remain basically unchanged. These three hypothetical examples I hope illustrate how each species might evolve different adaptaions to overcome the same environmental pressure brought on by a drying climate.
Perhaps a hominid species might evolve a bigger brain to answer the challenges presented by the new drier climate. Whatever the real incubating environmental pressures were they ultimately resulted in us and only us evolving our sophisticated brains. What I find perplexing is why has no prior species in all the long history of evolution developed a sophisticated intelligent brain. Some unique convergence of adaptations and environmental pressures allowed us to fill a niche only our species to date has filled.
A hypothetical example of this could be in the case of a drying of the climate. A snail species might grow a different shape shell that would allow less water evaporate by covering more exposed flesh. The earlier snails from the wetter climate era lacking this adaptation would not be able to survive in this new, drier environment. Over the same period of time in the same drying environment a species of fishing birds might see its source of food dwindle and dissapear and be forced to diversify and ultimately adopt a totally new food source, lets say lizards. Long spindly wading legs might shorten and grow stouter into running legs and a long beak ideal for catching fish might shorten and hook for better strength and grasping. Another species like ants might not have their niche disrupted at all and therefore remain basically unchanged. These three hypothetical examples I hope illustrate how each species might evolve different adaptaions to overcome the same environmental pressure brought on by a drying climate.
Perhaps a hominid species might evolve a bigger brain to answer the challenges presented by the new drier climate. Whatever the real incubating environmental pressures were they ultimately resulted in us and only us evolving our sophisticated brains. What I find perplexing is why has no prior species in all the long history of evolution developed a sophisticated intelligent brain. Some unique convergence of adaptations and environmental pressures allowed us to fill a niche only our species to date has filled.
Science: the PROOF shall set you free
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FreeThinker
- Posts: 91
- Joined: Mon Apr 03, 2006 7:35 pm
Again, well reasoned. But, again I have to express my doubts. The speed of some climate changes would not allow for the necessary adaptions. That is probably the reason why species become extinct due to climate change. If the adaption already exisited within the gene pool then the species could very well have an advantage. That puts the argument then back to why the big brain began to evolve before the change that made the big brain an edge.
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marduk
No doubt you'll correct me if you think I'm wrong, but actually having read 'On the Origin of Species by Natural Selection', Darwin made it very clear that NS worked on what was already available, that climate change etc caused no alteration to the basic stock, simply worked on what was available. ie Selection. If that pool of suitable adaption didn't already exist then the species could not adapt and died out.
What he couldn't explain was the mechanism that produced the changes that NS worked on. That was left to later researchers.
Has that idea changed then?
What he couldn't explain was the mechanism that produced the changes that NS worked on. That was left to later researchers.
Has that idea changed then?
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marduk
I've already told you more than 5 times that Darwins idea has changed and that the modern theory of evolution is a proven one which works on a genetic levelHas that idea changed then?
but for some reason you refuse to acknowledge it
lets face it Roy Darwin for you seems to be a huge stumbling block that you'll never get over
Yep, and funnily enough I agree it works on the genetic level. Never said other wise. Perhaps you haven't understood my posts. Nobody else seems to be having your difficulty. What Isaid earlier is also here in wik for you.
Natural selection is the biological theory that explains why living creatures seem to match their environmental niches so well – the process by which individual organisms with favorable traits are more likely to survive and reproduce than those with unfavorable traits. Insofar as there is genetic variability for the trait under selection, the genotypes associated with the favored traits will increase in frequency in the next generation. Given enough time, this passive process results in adaptations and speciation.
Look it up for your self.
Natural selection is the biological theory that explains why living creatures seem to match their environmental niches so well – the process by which individual organisms with favorable traits are more likely to survive and reproduce than those with unfavorable traits. Insofar as there is genetic variability for the trait under selection, the genotypes associated with the favored traits will increase in frequency in the next generation. Given enough time, this passive process results in adaptations and speciation.
Look it up for your self.
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marduk
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marduk
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FreeThinker
- Posts: 91
- Joined: Mon Apr 03, 2006 7:35 pm
Big Brain Evolution
The big brain in humans did not evolve before before it imparted an edge to our ancestors. With each incremental increase in its size a larger brain gave those individuals an advantage over their dimmer peers and thus they were more successful in reproducing. Over time the brain grew bigger and bigger until it has reached its current size. Although it is unclear exactly what the environmental pressures were that pushed our ancestors' brains to grow, clearly some pressure was exerted or we would have remained tree dwelling and small brained. Obviously the development of a large brain was an exceptionally good adaptation culminating in the modern human brain. Even our archaic human ancestors whose brains were of an intermediate size when compared to Sapiens and chimp brains were capable of producing tools and (since Homo Erectus) wielding fire. Our big brains have always given us an edge.That puts the argument then back to why the big brain began to evolve before the change that made the big brain an edge.
Science: the PROOF shall set you free