What did the common ancestor of all modern tetrapods look like 350 million years ago?

Which is it a characteristic of the animal kingdom? a. they include both vertebrates and invertebrates b. their skin is covered with hair or fur c. they are heterotrophs d. they are eukaryotic

*will mark brainliest to the first and correct answer less species diversity results in less a. oxygen b. food c. drinkable water d. all of the above

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited