Evolution and humans: speech and FoxP2 (Evolution)

by David Turell , Saturday, November 19, 2016, 00:30 (2925 days ago) @ David Turell

FoxP2 controls speech in humans but it is found in lesser animals and has the same effect there:

https://www.sciencedaily.com/releases/2016/11/161115114333.htm

"Dr. Jarvis and colleagues report the results of their investigation into the effect of a genetic mutation in the Forkhead box protein #2 (FOXP2) on the vocalization patterns of adult male mice. FOXP2 regulates speech production in humans. Individuals with deficiencies in FOXP2 protein have difficulty forming complex syllables and complex sentence construction.

"Although mice are unable to communicate using speech in the same way as humans, they do vocalize as a means of communicating with each other. Therefore this study sought to determine whether FOXP2 deficiencies have similar consequences for communication by mice as they do for humans.

They do.

***

"In their new study, the investigators wished to determine if there was an effect of a FOXP2 deficiency on the communication patterns of mice.

"The results showed that the FOXP2 heterozygotes have difficulty producing the complex vocal communication patterns that wildtype mice can create with ease -- as measured both by syllable length and the number of unique syllables produced over time. These divergences are particularly strong when comparing the communication of FOXP2 heterozygotes and wildtype males while in the presence of active female mice. In this context, the wildtype males were 3 times as likely as heterozygotes to produce the most complex syllable types and sequences available for review. Dr. Jarvis' team performed intricate statistical analyses to validate this finding, and their conclusion held true.

"Following the conclusion of all recordings, Dr. Jarvis' team used a process known as transsynaptic tracing from vocal larynx muscles to compare the vocal brain regions of wildtype and heterozygote FOXP2 mice. This study revealed that the heterozygote's vocal motor neurons were more widely distributed across the cortex than was the case for wildtype mice. This evidence suggests that the FOXP2 mutation affects both the placement and functioning of the neurons connected to effective communication, from mice all the way to humans.

"Prior research has shown a more limited role for FOXP2 than what is now becoming apparent. As Dr. Jarvis observes, "We believe that FOXP2 already had a pre-existing role in regulating vocal communication before human language evolved.'"

Comment: Not surprising if we believe in common descent. Humans just developed much further in anatomic and brain changes.