Marsupials are found in north america and australia, but they would not have been able to swim across the ocean. according to scientists, how did this group of organisms come to live on two separate continents? marsupials used to have adaptations that allowed them to swim but lost these adaptations over time. the two groups of marsupials evolved independently of one another on two separate continents. the continents were once connected, and marsupials were able to migrate over the land. the oceans were shallow in prehistoric times, which allowed the marsupials to travel from one continent to another.

You will create a molecular clock model for an arthropod gene. follow these guidelines to make your model: . your timeline will span from 90 million years ago to the present. the common ancestor in your model is an arthropod that lived 90 million years ago. the gene that you'll track codes for a protein in the species venom . the dna sequence youll track contains 10 nitrogen bases. you can choose the order of the bases and where the mutations occur. this gene mutates at a rate of approximately 0.76 base pairs every 17.1 million years. to build your model,/ calculate the estimated time period it takes for 1 base pair to mutate. the first time period will only show the common ancestor. at the beginning of the second time period, three lineages will diverge from the common ancestor, each with a different mutation in their gene sequences. the first and third descendant species will survive for the rest of the timeline. the second descendant species was extinct 50 million years ago. calculate how long it will take for one full base pair mutation to occur. explain your reasoning by constructing a mathematical equation