Tag Archives: evolution

Odd vertebrate gets rid of hundreds of genes early in development

Enlarge / There’s no jaw on the front of that face, and all the tissues you see have deleted hundreds of key developmental genes. (credit: Michael Heck, Oregon Fish and Wildlife)

Sea lampreys are parasites native to the northern and western Atlantic Ocean that suck blood and other vital fluids from their fellow fish. They have the distinction of possibly being the first destructive invasive species in North America; they entered the Great Lakes in the 1830s through the Welland Canal and have been killing trout there ever since.

They also have the distinction of having split off from the rest of the vertebrate lineage very early on, about 550 million years ago, before the evolution of jaws. This makes lampreys useful as a model

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As climates cool, adaptation heats up

Enlarge (credit: Getty Images / DEA Picture Library)

While natural selection is a big part of evolution, the theory now embraces much more than that. One of the big concepts that explains a lot of the pattern of evolution throughout history is called “adaptive radiation.” Adaptive radiation is a process in which environmental changes create new resources, challenges, and environmental niches, enabling rapid diversification of organisms from a single ancestral species.

Adaptive radiation provides a sound explanation that captures the effects of the interactions among organisms on species diversification. However, non-biological effects—the details of how environmental changes interact with species—are not easy to incorporate into this model and have not been extensively explored.

In a recent investigation published in PNAS, a team of scientists

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