Gen 2:19-20 explains how animals got their names:
Now the LORD God had formed out of the ground all the beasts of the field and all the birds of the air. He brought them to the man to see what he would name them; and whatever the man called each living creature, that was its name. So the man gave names to all the livestock, the birds of the air and all the beasts of the field.
Let’s assume for the moment that the above passage was written by mere mortals (the Elohist source to be exact) who lived around 850 bce in the Land of Israel. The statement that Adam named all of the birds and land animals sounds reasonable enough – there simply weren’t that many different animals in that area which the writer would have been familiar with. Now let’s assume that the above passage was written under divine inspiration (the verbal, plenary inspiration theory) where God guided the author to transmit his divine message exactly as he intended it. Suddenly, the statement seems ludicrous because we would expect God to know how many animals he created. For example, God would surely be aware of the Giant Pandas he created that are native only to China, or the Capivara found only in Brazil, or Beluga Whales and Polar Bares found only in the Arctic Ocean, or the Platypus found only in Australia. Adam would have his work cut out for him naming the myriad of animals found world wide – and the Beluga Whales would have died of dehydration and heat exhaustion in the process! But it gets worse. What about trilobites that died in the mass extinction at the end of the Permian about 250 million years ago (there are more than 10,000 fossil species of just trilobites alone!)? Did Adam name them? What is the ancient Hebrew word for it (or a word for it in any ancient language)? What about all of the other millions of extinct species of animal? What about the microbes (e. coli, amoebae, extremaphiles, etc., etc.)?
Walk me through it one more time: why should I believe that the first chapter in Genesis (for starters) is the divine Word of God?