It's said that the only constant in life is change, and when considering the history of life on earth we see changes in organisms played out over millions of years in the fossil record.
But the more things change, the more some creatures stay the same, and these ancient animals remain largely unaltered from their distant ancestors. These are colloquially referred to as living fossils, and several of these creatures can still be found in Manistee County today.
Living fossils are often long-enduring species that have lived through a large portion of geologic history, or cosmetically resemble related prehistoric species and share/retain many of its ancient traits.
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Sturgeon
Given its prehistoric, armored appearance, the sturgeon may be the quintessential living fossil.
Cosmetically this fish and its relative the paddlefish have remained consistent since the time of the dinosaurs.
The direct ancestors of sturgeon survived the Great Permian Extinction event that killed nine out of every 10 species, and soon these fish became dominant in every major river system in then-North America and Eurasia, according to Michigan Technological University environmental historian Nancy Langston in a 2019 article from Brandeis University.
Most sturgeon are armored and very long-lived, up to 150 years.
However, a 2013 study by researchers at the University of Michigan suggests that sturgeon have changed in at least one noticeable metric — size.
“Sturgeon are thought of as a living fossil group that has undergone relatively slow rates of anatomical change over time. But that’s simply not true,” said Daniel Rabosky, assistant professor in the University of Michigan department of ecology and evolutionary biology in a 2013 university publication.
Rabosky said that sturgeons have evolved a wide range of body sizes “very quickly.”
“There are dwarf sturgeon the size of a bass and several other species that are nearly as big as a Volkswagen,” Rabosky had said.
