1:10 AM
kotesh
When Maynard Smith reverse-engineered sex... he created a paradox. Sex should not exist; natural selection will favor asexual reproduction. The solution to the paradox is almost the Holy Grail of a large theoretical sub-branch of evolutionary biology, but it still has not been satisfactorily tracked down. — Mark Ridley, 1997 (1)
In spite of the number of ways bacteria can exchange genetic instructions, many of them haven't evolved very far — not as bacteria anyway. There are many modern bacteria that look very similar to fossils of the earliest bacteria of over 3 billion years ago. Eukaryotes are much better at evolving than prokaryotes. Eukaryotes first appeared on Earth about 1.7 billion years ago. They contain complex subunits, some of which — mitochondria and plastids — have their own DNA. With the appearance of eukaryotes, evolution began to accelerate. All multicelled animals and plants are made of eukaryotic cells. Where did they come from?
