In addition to the NCBI free archive linked above, you can prowl through various biological abstract archives like the one available here; various university molecular and cellular biology archives like the one available here; and various fascinating sites addressing genetics and genetics related evolutionary research, such as the human gene mutation database, the Metazome project, the NCBI human gene master list, the Blast assembled genomes database, and the EMBL nucleotide sequence database You can also, of course, browse through the many fossil databases available, with just a few of them here, here, here, here, here, here, here, here, here, here, here, here, here, here here here and here, and with a pretty good overview of "Paleontological Evidence to Date the Tree of Life" located here.
As you can see from the available literature, evolutionary biology overlaps many scientific fields, including organic chemistry, genetics, paleontology, geology, cell biology, zoology, etc. The point being that there is a great deal of "evidence to weigh," and if high school students will eventually be expected to "weigh" that evidence and "decide for themselves," they will need a solid grounding in it.
This means, of course, a solid grounding not only in biology and the theory of evolution itself, but also in the the scientific fields it draws upon and influences.
"Let the children decide" is all well and good, but give them the children the evidentiary ammunition first so their decision will at least be informed.
I will go you one step further. Darwinian Evolution is the bedrock premise of the aforementioned sciences, and the current state of the science will be severely affected (biology) if not destroyed (paleontology) by the removal of the foundation.
Did I intentionally simplify the skulls, you betcha. However, reading of the articles you have posted, will not "disabuse" me of anything. Each time I read one, and carefully disect it, I realize it is built on a series of assumptions, postulations, assertions and conjectures, that might explain the state of the evidence examined. However, I don't buy it. There is so much guessing and back patting, it is silly. For example if you click the second "here" link, click the "evolution resources" link and then click the first link and then click the first article, you will find the following, of which I pulled the first 2 questions as an example:
Animals: Tracing Their Heritage
Nicole King
An ActionBioscience.org original interview
Do animals have a common origin?
King: Yes. All animals, from sponges to jellyfish to vertebrates [animals with a backbone], can be traced to a common ancestor. So far, molecular and fossil evidence indicate that animals evolved at least 600 million years ago. The fossil record does not reveal what the first animals looked like or how they lived. Therefore, my lab and other research groups around the world are investigating the nature of the first animals by studying diverse living organisms.
Wow. We know they evolved 600 million years ago, but we don't have any "proof" in the way of a fossil record, so we will "guess" what the looked like by looking at things that are alive 600 million tears later. Now THAT is science! It get better.
You study multicellularity. Is there a connection to animal origins?
King: Eukaryotes [organisms with membrane-bound nuclei] range from those with a single cell, such as the amoeba, to complex multicellular animals, including humans. The vast majority of life on Earth has been dominated by unicellular life. At some point in the lineage leading to animals, multicellularity evolved. Multicellular organisms are those that have many cells. Their cells depend on each other, functioning in concert to sustain the life of the organism. So, the common ancestor of animals was a single cell.
No proof, just more gobblygook cause and effect effect reasoning. "At some point...multicellularity evolved...So, the common ancestor of animals was a single cell." No proof, no data, never been replicated in a science lab, just belief in the magic of genetic mutation and natural selection.
Every so called journal article I have looked at, while scary and full of big words that hurt to read, are full of the same silliness.
Speaking from experience as an advanced-degree holding organic chemist, I can assure you that organic chemistry is entirely and completely unbeholden to evolution in any form.
It looks like the chilrun of Texas are gonna have a lot of homework...they may have to shut-down their HS football and other sports teams.