SEP 21, 2020 6:52 PM PDT

Scientists Compare Structural and Functional Evolution with First Atlas of Cavefish Brains

WRITTEN BY: Amanda Mikyska

Astyanax mexicanus

Photo: Astyanax mexicanus (USGS)

 

Cavefish are fish that dwell in caves, unable to access the outside world. Often, they were separated from their closest relatives by the separation of continents or path caused by a river's formation. These 86 species have evolved independently of one another for millions of years, but their environment is very niche. This makes cavefish useful in studying convergent evolution: how species evolve the same trait because of similar environmental pressures, not from a common ancestor.

In a new study, researchers at Florida Atlantic University used neural imaging to measure brain signals and activity, then compared the neural activity to the fish's morphology and behavior. The comparison takes a more holistic account of how evolution is occurring. 

The morphology and behavior of cavefish have been studied extensively over the last 80 years because they evolved some unique characteristics. All cavefish are blind, and some have even lost the development of eyes. Their sleeping and eating habitats have evolved independently of the sun for millions of years, making for some unconventional behavior.  

Video: Dr. Prosanta Chakrabarty elaborates on why cavefish evolution is unique and what scientists can learn from that.

 

Researchers at FUA found that in four separate populations of A. mexicanus cavefish, all evolved different neural pathways for hunting behavior and sleeping patterns, both of which predate their speciation. They also found differences in the physical size of 13 common brain regions, including the cerebellum and parts of the hypothalamus.  

Due to their environment, cavefish populations are highly diverse, even within the same species. With the measurements of brain regions that are common across cavefish species, researchers have created an atlas that shows intraspecies variation and will guide future studies on this species' evolution and evolution principles. By studying morphology, neural activity pathways, and brain development, researchers were able to see that cavefish brains' structure and function do not evolve on the same linear track of evolution.   

The atlas is a significant new resource because it provides a foundation for future studies that compare the evolution of structure and function.  

 

 

Sources: Cell Magazine, Florida Atlantic University via EurekAlert!, Keene et. al., Sparks & Chakrabartyet. al., USGS

 

About the Author
  • Amanda graduated from the University of Massachusetts Boston with a degree in Biology. After working in research on creating biochemicals from genetically engineered yeast, she started freelance science writing while traveling the world. Now, Amanda is a Lab Manager and Research Assistant at the the University of Central Florida, studying the molecular phylogeny of parasitic wasps. She writes about the latest research in Neuroscience, Genetics & Genomics, and Immunology. Interested in working on solutions for food/water security, sustainable fuel, and sustainable farming. Amanda is an avid skier, podcast listener, and has run two triathlons.
You May Also Like
JUN 28, 2021
Neuroscience
New Findings in Mouse Brains Could Improve Neurological Research
JUN 28, 2021
New Findings in Mouse Brains Could Improve Neurological Research
Researchers led by the University of California have found important neurological differences between human and mouse br ...
JUL 23, 2021
Neuroscience
Does the Rise of Neurotech Spell the End of Humanity as We Know it?
JUL 23, 2021
Does the Rise of Neurotech Spell the End of Humanity as We Know it?
Researchers from Imperial College London have written an overview of currently available commercial brain-computer inter ...
JUL 24, 2021
Cannabis Sciences
Causal Link Between Cannabis Use Disorder and Schizophrenia
JUL 24, 2021
Causal Link Between Cannabis Use Disorder and Schizophrenia
A study from Denmark has found that the proportion of schizophrenia cases linked to cannabis use disorder has increased ...
AUG 16, 2021
Infographics
How Can We Make Sure Artificial Intelligence Won't Destroy Humanity?
AUG 16, 2021
How Can We Make Sure Artificial Intelligence Won't Destroy Humanity?
Artifical intelligence (AI) is becoming increasingly pervasive in daily life. While still far from the robitic humanoids ...
AUG 15, 2021
Neuroscience
Cats Prefer Free Food Over Food that Requires Effort
AUG 15, 2021
Cats Prefer Free Food Over Food that Requires Effort
If given a choice between a free meal and working for their food, domestic cats prefer the effort-free option. The study ...
AUG 30, 2021
Health & Medicine
For the love of java: Researchers find association, not causation, between excessive coffee consumption, brain size, and dementia
AUG 30, 2021
For the love of java: Researchers find association, not causation, between excessive coffee consumption, brain size, and dementia
Researchers find association, not causation, between excessive coffee consumption, brain size, and dementia
Loading Comments...