My understanding is that at 18 days there's detectable electrical activity in the tube that will eventually develop into a heart. Not a heart YET, and not beating per se, but significant (if the doctor can't detect this electrical pulse, it's a sign that a miscarriage is happening).

https://www.nbcnews.com/health/womens-health/heartbeat-bills-called-fetal-heartbeat-six-weeks-pregnancy-rcna24435

Chances are anti-abortion activists latch onto the tiniest piece of evidence and blow it way out of proportion to suit their agenda

There is no tube at 18 days or anything else there that resembles a heart or proto-heart. They are cardiomyocytes which are stem cells differentiated to become "heart cells." They in fact pulse after a few days of differentiation from stem cells. But it's not a heart beat. You can make them on a lab bench and they won't become a heart but they will still "beat" in a cell culture plate.

Thanks for the clarification!

Haha

The middle paragraph obviously has a typo, since 24 days after conception isn't toward the end of the first trimester

A critical juncture for those still subscribing to notion of the heart as the seat of thought and emotion?

Why aren't we talking about this?

Why people still subscribe to the somewhat outdated Egyptian notion that the heart is the brain as if that somehow changes anything anyways?

Although perhaps there is a case for this with some people, as this silly reversal where those who think science is a nefarious Satanic plot to, um, something something are the ones referring to science here while the science-means-God-is-dead contingent argue that life doesn't begin til thel stork drops the baby off with mommy at the hospital.
AKA, the heart is not the brain nor is the brain the brain because humans are stupid and they like it. Hence why the cranium has been shrinking in size since 8000 years ago, when the advent of agriculture allowed for the stupid to keep breeding.

till the*

Where've you seen that the cranium is getting smaller?

Skeletons in Central Asia (namely round what is now Khazakhstan) from 8000 years indicate that humans have become ever slighter in build since then as well as as the skull getting smaller as well (the former pattern in bodies was noticed first, the smaller brain conclusion came about a few years after).
The changes have been coupled with areas where agriculture was established.

oops, scuse my sloppy typng, I am tired...

Kazakhstan*

I can't spell for crap. That damned agriculture,,,

Poor Kazakhs! That's the only thing that comes to mind about them for most folks!

".... or prostitute" BWAHAHAHA, the way he says it

Interesting. my wife who is (probably mentioned this before, if I have, sorry) who has a Masters in Forensic psychology has been telling me that the frontal lobe has been getting larger over the span of our evolution.

This seems to me that our brains could be becoming more efficient in their construction? Making it smaller and tighter?

That trend in evolution ended with the introduction of agriculture.

Selective pressures have been eased, as a relatively steady supply of food made available to even those who haven't been able to acquire/produce it on their own assures a higher survival rate. This includes the more intellectually challenged, who, as we know, have a tendency to breed in greater numbers than those of higher intelligence, causing them over time to supplant bigger brained people.

So, where's the source? I wanna read this.

Heard this years ago, over a decade.

Is this where I get branded a neo-nazi Trumpite and my comments deleted because that's easier than disputing the facts I post? Did a rehash of that just last week with guess which colleague of yours who was in that party last year.

"Is this where I get branded a neo-nazi Trumpite and my comments deleted because that's easier than disputing the facts I post? Did a rehash of that just last week with guess which colleague of yours who was in that party last year."

No. All I am saying is, I don't trust it any farther than you can cite it. Nothing personal. They can't be factual until there's evidence to discuss it.

Trust is irrelevant. Heck, citation requests on this site usually lean rhetorical, just another item to dismiss without looking, especially given that any such info can be found on the web. Unless you have NYT Science section or Discovery Mag, Scientific American, Nat Geo going back years.... or even simple logic. Look at Trump's base. Any rivals to the ancients there? Socramagates coming this way,,,

"Trust is irrelevant. Heck, citation requests on this site usually lean rhetorical, just another item to dismiss without looking, especially given that any such info can be found on the web. Unless you have NYT Science section or Discovery Mag, Scientific American, Nat Geo going back years.... or even simple logic. Look at Trump's base. Any rivals to the ancients there? Socramagates coming this way,,," (Starting a new thread for ease. of replying)

I check sources the good 'ol fashioned way - I skim the article to find what is being referenced, once I find it I read that section more thoroughly, then I'll look at the website, what kind of articles they publish, then look at the author, see what they write, what they're known for, and after that cross reference the article itself to see if others have found the same conclusions. I mean, that is how you're supposed to do it, right?

*slowly looks at the bible nervously, wondering how far they'll go back for "research."*

The Bible says the sun once stood still in the sky for a whole day, so you know it's scientifically accurate