Why Can We Talk? 'Humanized' Mice Speak Volumes About Evolutionary Past

Mice found with a gene, similar to the human gene that is believed to influence speech, tho unable to speak show a huge link to humans evolutionary past. This is because human and mice’s genes are essentially the same and they work similarly. This study gives us a first glimpse that mice can be used to study not disease but also the history of human evolution. It is only in the last decade or so that scientist have discovered how similar mice and human genes are.

Wolfgang Enard of the Max-Planck Institute for Evolutionary Anthropology said that his team studies the genomic differences between humans and other primates. And important difference between humans and chimpanzees that has been studies by the team is two amino acids substitutions in FOXP2, these changes became fixed once human’s lineage had split for chimpanzees. Many changes in FOXP2 have occurred over the course of human evolution and this is the most likely candidate for the genetic changes that allow human speech. The study to determine this cannot be done on humans for obvious reasons. This lead researcher to introduce the substitutions into the mice’s FOXP2 gene, they identified that the mice’s gene is identical to that of chimpanzee’s so this is a reasonable model for ancestral human version.

Mice with the human FOXP2 show changes in brain circuits that have previously been linked to human speech. Intriguingly enough, the genetically altered mouse pups also have qualitative differences in ultrasonic vocalizations they use when placed outside the comfort of their mothers' nests. However Enard stated that not enough is known about mouse communication at this time to read to much into what this means. Although FoxP2 is active in many other tissues of the body, the altered version did not appear to have other effects on the mice, which appeared to be generally healthy.

The study of FOXP2 has shown that people with one nonfictional allele have show impairments in the timing and sequencing of orofacial movements, one possibility is that the amino acid substitutions in FOXP2 contributed to an increased fine-tuning of motor control necessary for articulation. Through the further studies of human mice and other primates the reason for speech will be discovered.

Original article: http://www.sciencedaily.com/releases/2009/05/090528120643.htm

Adam Gauger -42014016