Eggs, embryos, & politics

US  Senator Steve Daines, a Republican from Montana, recently used the concept of “pre-born” sea turtles while  arguing against a bill that would protect abortion rights by codifying Roe v. Wade. He stated

“If you were to take or destroy the eggs of a sea turtle,” Daines said while standing next to a poster pitting images of sea turtles “vs.” human babies, “the criminal penalties are severe….Why do we have laws in place that protect the eggs of a sea turtle or the eggs of eagles? Because when you destroy an egg, you’re killing a pre-born baby sea turtle or a pre-born baby eagle.”

Ancient ideas often re-appear in human thought long after they have been dismissed or discredited. Preformation is one of these.  In the 16th century alchemists were trying to convert lead into gold and they thought animal semen contained tiny, preformed animals that grew into adults when they obtained nourishment from the egg. This concept of preformation was applied to all animals, including humans. William Harvey (1578 –1657), physician to the King of England in the 17th century dismantled the idea Aristotle purposed that embryos formed from the mixture of paternal semen and maternal blood.  

Harvey developed the idea of omne vivum ex ovo (= all life comes from the egg) and this was the first definite statement against the idea of spontaneous generation (that is life spontaneously arises from non-life). He denied the possibility of life magically appearing from excrement and from mud, and pointed out that even worms have eggs.

Anton van Leeuwenhoek (1623-1732) a Dutch draper with an interest in optic lenses invented the microscope and discovered micro-organisms. van Leeuwenhoek also discovered sperm cells.  As microscope were refined, they gave humans the ability to appear into cells the basic structural units of organism. However, there was a problem – no one had seen mammal egg. This required another century – when Karl von Baer accurately descried a mammal ovum in 1826 or 1827.

The invention of the microscope and its refinements allowed detailed observations of how sperm and egg cells are produced and how embryonic development occurs. Human knowledge has been expanded even more with Mendelian genetics and knowledge of chromosome behavior, DNA and RNA, and the cellular processes of transcription and translation.

Human eggs and sperm do not contain preformed little humans. They contain sets of instruction coded in DNA molecules. Egg and sperm cells each contain twenty-three chromosomes – one member from each pair of the parents’ chromosomes. Most adult cells contain 46 chromosomes except for sperm and egg cells (and red blood cells that lose all their chromosomes). Chromosomes are packets of DNA.

Its understandable why sperm and eggs have been considered sacred cells by some religious groups. But based on current knowledge there is nothing supernatural or magical about sexual reproduction and governments and religions need to stay out of human reproductive issues.

 As for sea turtle and eagle eggs – Senator Daines, humans have made an assault on the biosphere eating sea turtlers to near extinction and polluting the environment with chemicals that make it difficult for eagles to successfully reproduce. That is why they are protected.