NOVA1: The Gene That Found Its Voice

    How humans developed the ability to speak has been a mystery to scientists for a very long time, especially because it doesn't leave behind physical evidence like fossils. A new study found a gene called NOVA1 changed a significant amount in humans somewhere around 250,000 and 500,000 years ago. NOVA1 might have played a role in helping early humans speak in more advanced ways. In a study, scientists inserted the human version of NOVA1 gene into mice, which resulted in the mice making more complex sounds, especially during mating calls. Dr. Darnell discovered that the human version of NOVA1 influenced the production of over 200 proteins in mouse brains, many of which are linked to how animals produce sounds. This points to NOVA1 potentially affecting the brain's control over speech-related behaviors. Dr. Jarvis and Dr. Darnell explain that NOVA1 is most likely just one of many genes involved in language development. The evolution of the gene became common in humans after we split from Neanderthals and Denisovans. Their research, along with studies on the FOXP2 gene, gives us new clues about how language might have evolved. 

 

    I chose this article because language is such a fundamental part of what makes us human, yet I never really thought about how it might have developed through genetics and evolved over time. It's fascinating how much the NOVA1 gene may have contributed to our ability to produce more complex sounds. I thought the study done using mice was especially interesting and informative because it demonstrated the impact the human version of NOVA1 has on brain function and sound production. When I found out that the mating calls became more complex with the introduction of the gene, I was honestly speechless. The study was a creative and effective way to connect genetics to speech-related behaviors, and it not only helped scientists better understand how language evolved but also made the topic more engaging and meaningful for me as a student.  

Can DNA explain the differences between humans and chimps?

Few DNA differences can be seen between our two species. Researchers are looking hard at those differences in hopes of identifying uniquely human stretches of the genome that help science narrow down what makes humans truly human. Two different stretches of DNA were found to be uniquely human that include the genome for larger brains.

One gene was found to not only cause bigger brains but also causes more surface folds as well. It seems to be a characteristic of primarily primates and the human brain. These folds increase the brains surface area which in turn gives more room for neurons to be able to process and store information.   

The Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, looked for a gene the was only active during the development period of the cortex very early in the embryo development. The cortex that is the thin outer layer of the brain is used to memory, attention, awareness, thought, language, and consciousness.

Researchers found this gene by observing gene activity in an aborted human fetus while comparing it to tissue from a mouse embryo. They identified 56 human genes the mouse tissue lacked.  The most active was a gene called ARHGAP11B, a partial duplication of an existing gene. The duplication arose sometime after human evolution split off from the line that led to chimps some 5 or 6 million years ago. It is uniquely human, being present in Neanderthals and Denisovans, our long-gone kin, as well as anatomically modern humans, the last Homo standing. (That’s us.)

The researchers found out what ARHGAP11B did by putting it into transgenic mice. It doubled the mice’s cortical stem cells and increased their brain size.

https://www.geneticliteracyproject.org/2015/02/20/of-intelligent-mice-and-men-human-genes-give-mouse-bigger-brain/

https://www.geneticliteracyproject.org/2016/03/31/humans-share-99-of-genes-with-chimps-can-dna-explain-differences/

Geneticists hope to unlock secrets of bats' complex sounds

Animal communication is a topic that still baffles many, and bat communication consisting of: calls, chirps, and shrieks specifically are still a mystery to humans. The project that was taken underway to further understand bat communication was titled Bat 1K and will involve sequencing the genome of more than 1,000 different bat species. The project was just recently announced with the hope of also gaining a deeper understanding of bats' abilities to fly at night using echolocation, their longevity and long life-spans, as well as relatively strong immune systems. Their immune systems are so strong in fact, that some are capable of resisting the Ebola virus.

Unlike many animals whose genes are better understood, bat genes have barely been studied in comparison to other mammals. Different bat behaviors have been observed including: chattering, screeches, whistles, and barks and it's even been identified that certain species of juvenile bats learn songs from elder male bats, who teach them to apply the behaviors during the search for food, mating, and defending their territory, but the reason as to why and how, is unclear.

Only roughly 50 bat species have had vocal sounds analyzed yet, and four species have demonstrated the ability to learn vocal sounds from their fathers or other male bats. The four species are the greater sac-winged bat, the Egyptian fruit bat, the pale spear-nosed bat, and the greater spear-nosed bat, and all four species differ in location, age, sex, and vocal sounds.

The gene that has been correlated to speech and communication in bats has been identified as FOXP2. It is a gene involving how humans learn languages and how songbirds learn vocal patterns, but the gene has evolved and is more diverse in bats, which remains an unanswered question. Researchers hope to find other genes that are involved in bat communication, as well as other species of bats that exhibit this capacity.

I believe that this research is essential for a better understanding of the many vital bat species, their purpose, and finding a way to eradicate the negative stigmas that the bats carry. Not only would understanding the behavior and communication of bats be in their best interest, but the research may open doors to understanding other species' communication pathways and the genes involved.

http://www.nature.com/news/geneticists-hope-to-unlock-secrets-of-bats-complex-sounds-1.20997

"The Language Gene"

The Max Planck Institute in Leipzig, Germany presented a study recently about a gene called FOXP2. This is a human gene that is believed to have mutated 500,000 years ago. But it is not the age of the gene that is important. Researchers believe that this gene is responsible for an increased rate of learning. This gene may have been one of the factors present when our ancestors began to develop the complex muscle movements that eventually produced sounds and noises and ultimately advanced enough to develop language.

Genes similar to this have been found in other vertebrates and code for the development of the brain stem and spinal cord. The human gene was planted into mice and they were observed. Curiously, the test mice learned at a more accelerated rate then the control mice. This supported the theory that the gene is responsible for better cognitive development. This is an amazing thing to think about. Scientists may have discovered a gene that could explain how we are able to advance the way that we do in this world.

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