Sex versus Gender in Sea Urchins and Leeches Two Centuries after Lamarck 1816

No other words arouse more interest and excitement than “sex” and “gender”. However, clear, concise definitions of these terms sensu stricto are elusive, despite the fact that Carolus Linnaeus (1707-1778) published, in 1753, a “Sexual system” of plant systematics (with reference to gender issues in humans) that was later abandoned by botanists. Recently, theterm “sex” (in humans) was used with reference to organs, chromosomalcomplements and hormones related to reproduction. In contrast, “gender” was defined as “cultural attitudes that shape ‘feminine’ and ‘masculine’ behaviors that are learned and vary by culture, historical era, and ethnicity”. 

In addition, in animal research, the “g-word” is used to indicate the attitude of investigators with respect to the handling of male or female laboratory animals. Here, I analyze the original “Linnaean” meaning of“sex” within the context of bi-parental reproduction, with reference to Lamarck’s (1816) description of a marine model organism that has later been used to elucidate this process at the sub-cellular level. In addition, Charles Darwin’s (1809-1882) concept of different gender roles in sexually reproducing groups of males/females and hermaphroditic animals is addressed.