“If I take a single bacteria and let it grow, then plate it on ten plates and subject it to ten stresses; I can repeatably get it to “adapt”/”evolve” to be resistant to those ten different stresses through novel variations that are selected for in that environment.”
Why then, in the big Petri dish that is planet Earth, and in these billions of years, has the single-celled Plasmodium not evolved a resistance to cooler climates? Do you think you could grow Plasmodium under certain environmental stresses and “evolve” a variant of this parasite to be resistant to cooler climates?
What kind of environmental stress, or sequence of stresses, would result in uni-cellular organisms evolving into multi-cellular organisms. What survival advantage would result? Just what would the mutations conceivably be that would result in multti-cell organisms? Just saying mutations/selection/time doesn’t explain anything about how this would come to be.
As to what adaptations are needed, we can look at one celled life that forms cooperative colonies, or slime molds that exist unicellularly and then team up to form multi-cellular reproductive structures.
As with the eye, the “missing links” between are actually living among us.
MOVE THE GOAL POSTS:
I have been arguing that natural selection of genetic variation is the only scientific explanation for evolving resistance to novel antibiotics, skin color differences, and the INEVITABLE small changes in DNA that will accumulate between separate populations.
Unable, QUITE apparently, to deal scientifically with any of these subjects, the goal posts are moved so that the mechanism must also explain to your satisfaction every nonexistent creature that you think should exist, the rise of multi-cellular life, and perhaps also the origin of life itself?
That tactic sure seems to me like an admission on your part that the ONLY scientific explanation for skin color differences, development of antibiotic resistance, adaptation to the environment through changes in the DNA within the population - is natural selection of genetic variation.