Here are links (and accompanying headings) to great news from 03-24-2021 about how we now know in a major way why human brains are so much bigger than non-human ape brains. What is reported in the articles is the effect of the type of expression in just one gene making the huge difference! See the following:
- "Lab-grown mini ‘brains’ of humans and apes reveal why one got so much bigger: Using lab-grown mini-brains, scientists have figured out why humans have bigger brains than those of apes" at
https://www.livescience.com/human-ape-brain-evolution-differences.html .
- "Scientists discover how humans develop larger brains than other apes" at https://phys.org/news/2021-03-scientists-humans-larger-brains-apes.html . That article says in part the following:
"A new study is the first to identify how human brains grow much larger,
with three times as many neurons, compared with chimpanzee and gorilla
brains. The study, led by researchers at the Medical Research Council
(MRC) Laboratory of Molecular Biology in Cambridge, UK, identified a key
molecular switch that can make ape brain organoids grow more like human
organoids, and vice versa.
...
To uncover the genetic mechanism driving these differences, the researchers compared gene expression—which genes are turned on and off—in the human brain organoids versus the other apes.
They identified differences in a gene called 'ZEB2', which was turned
on sooner in gorilla brain organoids than in the human organoids.
To test the effects of the gene in gorilla progenitor cells, they
delayed the effects of ZEB2. This slowed the maturation of the
progenitor cells, making the gorilla brain organoids develop more
similarly to human—slower and larger.
Conversely, turning on the ZEB2 gene sooner in human progenitor cells
promoted premature transition in human organoids, so that they
developed more like ape organoids."
Thus, scientists have discovered a major part of the explanation to what the WT and other creationist organizations imply is an solvable mystery of how unguided evolution could have caused such a huge difference in brain size between Homo sapiens and non-human apes. [For example, see page 55 of the WT's book called Is There a Creator Who Cares About You?]
The God (as Creator) Hypothesis and the Intelligent Designer/Creator Hypothesis are completely unnecessary (and superfluous) in explaining how diversity of life came into existence on planet Earth.