I originally published When Does a Human Life Begin? 17 Timepoints here at DNA Science in 2013. My intent was to inform those who confuse embryo with fetus with baby by presenting how biologists describe human prenatal development – beginning at fertilization. Human gestation is on average 38 weeks, not 40, according to biology.
I rerun "17 Timepoints" periodically to counter assaults on woman's reproductive rights – which unfortunately happens with disturbing regularity.
In 2017, I reposted when The Federalist published "Life Begins at Conception, Says Department of Health and Human Services."
Then in September 2021, Genetic Literacy Project reran "17 Timepoints" with the updated headline (which I didn't write) Viewpoint: 'The fetus is 1/25th of an inch' — Texas abortion ban bungles the science on when human life begins, contends biologist and professor.'
And along the way, various right-to-lifers have responded to my post with insults to my expertise, but no sign of actually understanding the biology. So it goes …
Now the rerun of "17 Timepoints" is in response to the leaked Supreme Court document threatening Roe v Wade, published in Politico and written by Josh Gerstein and Alexander Ward. To paraphrase Ronald Reagan, here we go again.
To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.