How might mars be different if its surface did not contain so much iron?

How do you date a sample of rock that you suspect as being one of the earliest on earth

The term facultative anaerobe refers to an organism that

Which of the following can occur to two segments of a population if they are geographically isolated 1.) they can only share some types of genes 2.)both groups most likely become extinct 3.)they find a way to come back together 4.)eventually they become separate species