The dna of a snake changes to make its venom stronger

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

Plz ! what does it mean for an allele to be dominant?

As scientists have investigated evolution from a variety of fields, they have found that some of darwin's orginal ideas were inaccurate or incomplete. t explanation provided by evolution was updated each time to reflect the new information they found. what does this suggest about the theory of evolution? it has become a stronger and clearer theory as new information is collected.