First Sex?

 
Here's the opening paragraphs from a news item on the National Geographic website ["First Sex" Found in Australian Fossils?].

Sex is part of the "oldest profession" and often called the subject of the "world's oldest joke." Now scientists think they've found evidence of the oldest known creatures to engage in sexual reproduction.

A new study suggests that nature's first sexual encounter took place among tubular invertebrates called Funisia dorothea, which lived about 565 million years ago.

This is an example of bad science writing. Sexual reproduction is a phenomenon seen in many bacteria and in all eukaryotes (with minor exceptions). Animals are not the only eukaryotes that have sex. Plants, do it; fungi do it; and so do all single-cell eukaryotes.

The ancestors of these tube worms were having sex for at least a billion years before the Neoproterozoic. The idea that these organisms were "nature's first sexual encounter" is silly.

Who is responsible for this misrepresentation of the evolution of sex? The paper by Droser and Gehling (2008) was published in Science last week. The only reference to sex in the peer-reviewed paper is the following ....

The branching patterns and rarity of branching of Funisia is consistent with metazoan asexual budding. The consistency of tube widths on individual bedding surfaces (Fig. 1, A, I, and J), the densely packed nature of the attachment structures, and the clustering pattern of developmental stages of attachment structures on individual bedding planes suggests that the juveniles settled as aggregates in a series of limited cohorts.

These solitary organisms thus exhibit growth by addition of serial units to tubes and by the division of tubes, and dispersed propagation by the production of spats. Among living organisms, spat production is almost ubiquitously the result of sexual reproduction but is known to occur rarely in association with asexual reproduction (8). Hence, despite its morphological simplicity the Neoproterozoic F. dorothea provides evidence of a variety of growth modes and a complex arrangement for the propagation of new individuals. In living organisms, synchronous aggregate growth may result from a variety of factors—including response to competition, sediment disturbance, and heterogeneity of the substrate—and has the advantage of reducing competition for space between clones and can also decrease gamete wastage (9, 10).

There's nothing in the paper about these organisms being the first to reproduce sexually—that wouldn't have survived the reviews. The only remaining question is why did the author (Droser) allow herself to be quoted in a press release when she must have known that it was misrepresenting the paper?

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Droser, M.L. and Gehling, J.G. (2008) Synchronous Aggregate Growth in an Abundant New Ediacaran Tubular Organism. Science 319:1660-1662. DOI: 10.1126/science.1152595