Quantum: Ancient immunity

A QUANTUM OF SCIENCE

New findings show adaptive immune system may not be new invention

Recently, scientists at Emory University in Atlanta reported that lampreys - a cartilaginous fish which evolved around 500 million years ago - is the oldest organism yet found to possess an adaptive immune system like that of humans. Previously, the adaptive immune system was believed to have originated in sharks, which evolved around 400 million years ago. This extra 100 million years is a big deal because the lamprey is a much earlier splinter from the vertebrate branch of the tree of life, and could mean that other even more ancient predecessors had already figured out how to "record" microbial invaders and repel them better in future infections.

Another interesting note: the age of cartilaginous fishes was known as the Silurian period, a time culminating in the so-called Law Event in which approximately 60% of aquatic species became extinct through a series of rapid climatic changes. Could the adaptive immune system have helped lampreys and sharks survive?

For more information:
The Scientist: Ancient organism, modern immunity

© A Quantum of Science / Peter Smalley (2009)
Reproduction with attribution is appreciation