Are we humans simply remodelled apes? Chimps with a tweak? Is the difference between our genomes so minuscule it justifies the argument that our cognition and behaviour must also differ from chimps by barely a whisker? If “chimps are us” should we grant them human rights? Or is this one of the biggest fallacies in the study of evolution? NOT A CHIMP argues that these similarities have been grossly over-exaggerated - we should keep chimps at arm’s length. Are humans cognitively unique after all?
Friday, 11 December 2009
When A Chimp Is Not A Chimp
For those of you still interested in Ardi - Ardipithecus ramidus - and what she represents to the study of human origins and the nature of the common ancestor between humans and chimps here is a nice, simple little piece from Pat Shipman ("Taking Wing' and others) in American Scientist.
Tuesday, 8 December 2009
No Charges To Be Filed Against Travis's Owner
Charla Nash - the woman who was horribly disfigured though being attacked by Travis the chimp in Stamford, Connecticut - has been all over the airwaves recently, including an appearance on "Oprah". While she continues to press a suit for $50 million damages, the State Attorney's office has confirmed that there are no grounds for charging Travis's owner, Sandra Herold, with anything, since she did not disregard warning signs or history of violence and Nash was known to her attacker.
Meanwhile, the take home message of this sorry affair is - don't give a primate for Christmas!
Meanwhile, the take home message of this sorry affair is - don't give a primate for Christmas!
Transcription Factor Differences Guide The Different Development Of Chimp And Human Brains
In the chapter called THE RIDDLE OF THE 1.6% I explain how relatively small differences between chimps and humans at the level of DNA nucleotide sequence in genes can be tremendously amplified by a variety of mechanisms that change how hard a gene works - and when - and therefore how much protein it produces. Lisa Stubbs and Katja Nowick, from the University of Illinois, have just provided important and specific evidence for how this can come about. It has been understood for some time that some genes act as master controllers of an orchestra of subservient genes because they produce proteins called transcription factors that attach to a large number of genes and either ramp up or reduce their activity. These gene expression differences are particularly pronounced in the human brain, versus that of the chimpanzee and are involved in various processes that supply energy sources to the greedy human brain or are involved in building larger and longer synapse networks etc. etc. As Stubbs says, "These differences fit what we know because the human brain is so much larger and proteins need to be shuttled a long way out to the synapses. A higher requirement for metabolic energy has also been demonstrated independently for human brains."
The duo looked at a family of transcription factors known as the KRAB zinc finger genes and discovered 90 transcription factors that were implicated in the activity of 1000 genes - causing an upsurge of activity in the human brain. "Once this network of transcription factors is established, changes in the network can be amplified because transcription factors control other genes", says Nowick, "even a small change in transcription factor expression can therefore produce a large effect on overall gene expression differences between chimpanzees and humans." Stubbs adds that: "Our very strong bias is to believe that these transcription factors are involved in speciation and traits that make species unique"
The duo looked at a family of transcription factors known as the KRAB zinc finger genes and discovered 90 transcription factors that were implicated in the activity of 1000 genes - causing an upsurge of activity in the human brain. "Once this network of transcription factors is established, changes in the network can be amplified because transcription factors control other genes", says Nowick, "even a small change in transcription factor expression can therefore produce a large effect on overall gene expression differences between chimpanzees and humans." Stubbs adds that: "Our very strong bias is to believe that these transcription factors are involved in speciation and traits that make species unique"