Tag Archives: age of fishes

Yale Study Reveals New Family Tree for Ray-Finned Fish

The most common lineages of fish found today in oceans, lakes, and rivers evolved about the same time as mammals and birds, a new Yale University-led study shows.

The comparative genetic analysis of more than 200 fish species, reported the week of Aug. 6 in the Proceedings of the National Academy of Sciences, gave an earlier than expected evolutionary birthday to well-known teleost — or ray-finned — fish such as salmon, bass, or tuna.

The analysis also shows that the very earliest lineages of living teleost fish were eels and bonefishes, not tropical freshwater bonytongue fish as some scientists had proposed. (more…)

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The Winners of Mass Extinction: With Predators Gone, Prey Thrives

*Extinction of fishes 360 million years ago created natural ecology experiment*

In present-day ecology, the removal or addition of a predator in an ecosystem can produce dramatic changes in the population of prey species. For the first time, scientists have observed the same dynamics in the fossil record, thanks to a mass extinction that decimated ocean life 360 million years ago.

What was bad for fish was good for the fish’s food, according to a paper published online in Proceedings of the National Academy of Sciences. Researchers from the University of Chicago, West Virginia University and The Ohio State University found that the mass extinction known as the Hangenberg event produced a “natural experiment” in the fossil record, with results that mirror modern observations about predator-prey relationships. (more…)

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