Bear Wild
Well-Known Member
Well my Odin post did not stimulate discussion in this area so here is my convergent discussion.
Bird and mammal brain convergent evolution.
Evolution predicts that similar adaptations can develop from different pathways to create similar adaptive features. This is the opposite of an intelligent design pattern. For me one of the most impressive examples of this is bird and mammal convergent evolution of brain patterns.
First there must be and end to the inappropriate association with “bird brain” as not intelligent. Thanks to the lack of insight of Skinner who love to torture pigeons and other animals in artificial nonrepresentative ways we have a misrepresentation of birds and animals. All I have this to say to Skinner is (You ******* as*****! How could you be so ******* *****! Glad to get that off my chest)
What we have learned in the last 30 years about bird intelligence is utterly amazing and the clearest evidence of convergent evolution.
First the misconception the bird brains come from the striatum of the brain and is incorrect. The forebrain of birds is of pallial in origin. Thus the modern bird and mammal forebrain is derived from the pallial.
This origional error was that avian brain was derived from striatum or basal ganglion with instinctual behaviors only of feeding sex and parental behavior.
The telencephalon of birds is derived from the pallium and is functionally the same as the mammalian cortex from the same embryotic forebrain but instead of the layered cortex in mammals birds have nucleated pockets of grey matter.
When you realize that Corvids (crows, ravens and similar species) and parrot brains are relatively the same size as primates when body mass is accounted for you start to appreciate our feathered friends.
Early comparative psychologists (will not digress to complain further of Skinner) choose bird species such as pigeons to be representative of all birds. This is the same as choosing a mouse to be representative of humans. This lead to a misrepresentation of the avian world.
We finally realize that this convergent evolution produced nucleated patterns in birds instead of laminated pattern as in mammal brains.
One exception may be the wulst/hyperpallium on the dorsal forebrain of birds with its three to four layer and associated neurotransmitters.
We see how evolution of vocal learning has developed in in song birds and parrots very similar to humans. With similar neuro networks involved creating similar patterns as in humans. Cetaceous mammals have similar ability but with yet unknown neural networks to be described.
And the most impressive is the caudolateral nidopallium which has similar neuro connectivity, neurochemistry, neurophysiology and function to the dorsolateral prefrontal cortex. For all those not familiar, the dorsolateral prefrontal cortex is the area in the brain of humans which we pride ourselves of being so cognitively in control. There is also a similar dopamine distribution involved with motivations. Just as amazing there are projections to the somato-motor and limbic areas of the basal ganglion are similar in influence of behavioral and affective responses to the prefrontal cortex.
Corvid brains have functionally analogous structures to the ventromedial prefrontal cortex and neurological connections important of theory of mind.
What this convergent evolution shows is the plasticity of the genetic code to create patterns of adaptations with different patterns to achieve the same results as an advantage to survival. What more could you ask for as evidence of evolution?
Source (well at least one of them)
www.cell.com/current-biology/pdf/S0960-9822(05)01404-1.pdf
Bird and mammal brain convergent evolution.
Evolution predicts that similar adaptations can develop from different pathways to create similar adaptive features. This is the opposite of an intelligent design pattern. For me one of the most impressive examples of this is bird and mammal convergent evolution of brain patterns.
First there must be and end to the inappropriate association with “bird brain” as not intelligent. Thanks to the lack of insight of Skinner who love to torture pigeons and other animals in artificial nonrepresentative ways we have a misrepresentation of birds and animals. All I have this to say to Skinner is (You ******* as*****! How could you be so ******* *****! Glad to get that off my chest)
What we have learned in the last 30 years about bird intelligence is utterly amazing and the clearest evidence of convergent evolution.
First the misconception the bird brains come from the striatum of the brain and is incorrect. The forebrain of birds is of pallial in origin. Thus the modern bird and mammal forebrain is derived from the pallial.
This origional error was that avian brain was derived from striatum or basal ganglion with instinctual behaviors only of feeding sex and parental behavior.
The telencephalon of birds is derived from the pallium and is functionally the same as the mammalian cortex from the same embryotic forebrain but instead of the layered cortex in mammals birds have nucleated pockets of grey matter.
When you realize that Corvids (crows, ravens and similar species) and parrot brains are relatively the same size as primates when body mass is accounted for you start to appreciate our feathered friends.
Early comparative psychologists (will not digress to complain further of Skinner) choose bird species such as pigeons to be representative of all birds. This is the same as choosing a mouse to be representative of humans. This lead to a misrepresentation of the avian world.
We finally realize that this convergent evolution produced nucleated patterns in birds instead of laminated pattern as in mammal brains.
One exception may be the wulst/hyperpallium on the dorsal forebrain of birds with its three to four layer and associated neurotransmitters.
We see how evolution of vocal learning has developed in in song birds and parrots very similar to humans. With similar neuro networks involved creating similar patterns as in humans. Cetaceous mammals have similar ability but with yet unknown neural networks to be described.
And the most impressive is the caudolateral nidopallium which has similar neuro connectivity, neurochemistry, neurophysiology and function to the dorsolateral prefrontal cortex. For all those not familiar, the dorsolateral prefrontal cortex is the area in the brain of humans which we pride ourselves of being so cognitively in control. There is also a similar dopamine distribution involved with motivations. Just as amazing there are projections to the somato-motor and limbic areas of the basal ganglion are similar in influence of behavioral and affective responses to the prefrontal cortex.
Corvid brains have functionally analogous structures to the ventromedial prefrontal cortex and neurological connections important of theory of mind.
What this convergent evolution shows is the plasticity of the genetic code to create patterns of adaptations with different patterns to achieve the same results as an advantage to survival. What more could you ask for as evidence of evolution?
Source (well at least one of them)
www.cell.com/current-biology/pdf/S0960-9822(05)01404-1.pdf