I don't know why so many of these articles focus on the biological/human aspect of the problems. So much other stuff needs to be solved first, before a human can even visit, that's it's really jumping the gun to think of humans there, at all.

From the first part of the article:

The thin atmosphere also means that heat cannot be retained at the surface.

and

Bruce Jakosky and Christopher Edwards from the University of Colorado, Boulder sought to understand how much carbon dioxide would be needed to increase the air pressure on Mars to the point where humans could work on the surface without having to wear pressure suits, and to increase temperature such that liquid water could exist and persist on the surface. Jakosky and Edwards concluded that there’s not nearly enough CO2 on Mars...

So even if you could set up a radiation-proof box on the surface (or sub-surface) of Mars, you have to keep it warm.

Now you have to generate heat. Constantly. 24/7/365 (or whatever the Martian analog is).

Because all the heat you are generating is being bled off into space, due to the lack of atmosphere.

When I first started camping with the Boy Scouts, my pack leader told us not to lay our bed on the ground, if at all possible. Because you will get cold. Not because the ground is cold, but because your body will try to heat the ground - ALL of it - with your body heat. And you are basically trying to warm up the whole earth with your body heat. (So use a hammock, or a pad to separate you from the ground, and keep your body heat inside your body!)

So just to put a rabbit in a box on Mars, you now need a highly insulated box, with a heater, and an infinite power source.

Let's just start there, before trying to guess how gestation will work, alright? :-)

Our DNA would have to be tailored specifically to enable a long, healthy life on Mars, including genetic tweaks for good muscle, bone, and brain health. These traits could be made heritable, such that Martian colonists could pass down the characteristics to their offspring. In cases where biology is not up for the task, scientists could use cybernetic enhancements, including artificial neurons or synthetic skin capable of fending off dangerous UV rays. Nanotechnology in the form of molecular machines could deliver medicines, perform repair work, and eliminate the need for breathing and eating. Collectively, these changes would result in an entirely new species of human—one built specifically for Mars.

I enjoyed this article, but I thought it was silly to have a section about genetic and cybernetic modifications when it opened by complaining about NASA/Elon being too sci-fi for their own good.