The beginnings of a brain first become apparent around four weeks after conception when the neural plate folds to form the neural tube
One very specific way that humans caused changes in the atmospheric CO2 levels is the fossil fuels that the humans are burning is causing an increase in the CO2 levels. Other ways humans are doing this is by driving cars, deforestation, and an increased industrialization that releases CO2 into the atmosphere.
This movement is called diffusion
<span>A. a second group of scientists finding significant differences in the DNA of the two different subspecies </span>