[hopespringseternal]

To avoid the argument of what stage of development it is a human - when the first appears.

On what day is that? How much cognitive function do you suppose that first brain cell has?

Or do you suppose that your date is just as arbitrary and undefined as any other along the timeline of fetal development, chosen merely for your own convenience?

[toast]

I read it someplace. I didn't make it up.

14 days is when the cells begin to differentiate. It is a measured time. That time may be slightly different for each individual embryo but it is definite there is no brain function.

I read that there are some researchers that don't like to work with embryo's past this age because even they worry about these things.