Ned Friedman, director of the Arnold Arboretum, Harvard University, writes about the swimming of the Ginkgo sperm on his blog:
"Why would a ginkgo tree, whose seeds may be found more than a hundred feet in the air, resort to swimming sperm to find a mate? The answer is rooted in history. The ancestors of all land plants (green algae) had swimming sperm that sought out (swam to) eggs to create the next generation. A pretty good idea if you live full time in the water. Amazingly, after all of these years (475 million, to be precise, since the first green algae colonized land), sperm of ginkgo trees, cycads, ferns, horsetails, mosses, and other groups of plants still find their egg-mates by swimming, tracking the chemical signals that the conspecific (same species) egg is emitting to attract a suitor. Truly, this is a vestige of evolutionary history."
Read full article here.
More info on my website: History-page + Propagation-page and Ovule-page.
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