The La Brea Tar Pits in Los Angeles are the site of millions of fossils from the ice age. Woolly mammoths, giant sloths, dragonflies, and other plants and animals from this era have been found in these pits. Scientists at the tar pits discovered that many of the smaller animals they extracted from the pits still exist around Los Angeles today. But many of the larger mammals—such as woolly mammoths and saber-toothed tigers—are now extinct. Why do you think this is the case? What can scientists learn about Los Angeles' climate history by studying the specimens found in these tar pits?

Scientists learn how climatic changes during the ice age affected life in this region by analyzing specimens found in these tar pits  

Explanation:

La Brea Tar Pits are a group of tar pits in Los Angeles. Many preserved remains of ancient organisms (i.e., fossils) were extracted from the tar, including, among others, Western horses, prehistoric camels, three-toed tapirs, rodent bones, insects, mollusks, wood, plants, etc. The oldest fossils have been dated to be approximately 38,000 years ago by radiometric techniques. Moreover, the Last Glacial Period was the most recent glacial period within the Quaternary glaciation, which encompassed the period between 115,000 to 10,000 years ago. This period (LGP) encompassed the Last Glacial Maximum (LGM), which occurred about 20,000 years ago. In consequence, many of the fossils found in La Brea Tar Pits evidence how the ice age affected life in this region. Moreover, many of the fossil species extracted from the tar are still present today, thereby indicating how these species adapted to fluctuating climatic conditions, whereas certain species couldn't adapt fast enough as the environment changed and therefore they went extinct.

a- all cells come from pre-existing cells