Big brains are all in the genes

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Scientists have moved a step closer to understanding genetic changes that permitted humans and other mammals to develop such big brains.

During evolution, different mammal species have experienced variable degrees of expansion in  size. An important goal of neurobiology is to understand the  underlying these extraordinary adaptations.

The process by which some species evolved larger brains – called encephalization – is not well understood by scientists. The puzzle is made more complex because evolving large brains comes at a very high cost.

Dr Humberto Gutierrez, from the School of Life Sciences, University of Lincoln, UK, led research which examined the genomes of 39 species of mammals with the aim of better understanding how brains became larger and more complex in mammals.

To do this, the scientists focussed on the size of  across these species. Gene families are groups of related genes which share similar characteristics, often linked with common or related . It is believed that large changes in the size of gene families can help to explain why related species evolved along different paths.

Written By: Marie Daniels
continue to source article at phys.org

3 COMMENTS

  1. There must be an evolutionary advantage in having a large brain for genes to be expressed in this way even if it is expensive to maintain. But a large brain is of limited use if it cannot be used to advantage and the surprise for me is that despite our large brains, human cognition has some remarkably powerful biases that are irrational and lead to unpredictability in judgement making. That we have not eliminated these biases indicates they were probably useful in our past for survival and are either still useful or we have not yet evolved to the point where they are no longer a useful adaptation.

    • In reply to #1 by Vorlund:

      But a large brain is of limited use if it cannot be used to advantage and the surprise for me is that despite our large brains, human cognition has some remarkably powerful biases that are irrational and lead to unpredictability in judgement making. That we have not eliminated these biases indicates they were probably useful in our past for survival and are either still useful or we have not yet evolved to the point where they are no longer a useful adaptation.

      Vorlund, you are making no distinction between genetic adaptive evolution and cultural adaptive evolution.

      Cultural adaptive evolution (learning and invention) can move much faster than genetic evolution (mutation and selection pressure) can move. Irrational biases can decline rather rapidly under the right circumstances. The twenty-first century is providing many such favorable circumstances. For example, richarddawkins.net did not exist prior to 2006, and Youtube began in 2005.

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