500
a. the most appropriate sample of rock in which to search for a transitional species, between lobe-finned fish and amphibians
b. TWO pieces of evidence provided by fossils of transitional species that would support the hypothesis that amphibians evolved from lobe-finned fishes.
Fossils of lobed-finned fished, which are ancestors of amphibians, are found in rocks that rae at least 380 million years old. Fossils of the oldest amphibian-like vertebrate animals with true legs and lungs are found in rocks that are aproximately 363 million years old.
Three samples of rock are available that might contain fossils of lobe-finned fished and amphibians: one rock sample that is 350 million years old, one that is 370 million years old, and one that is 390 million years old.
a. 370 MYA --> the time period between Lobe-Finns and Amphibians
b. legs/limbs/digits, vertebrae, flat skulls, ribs, flexible neck. Scales. Teeth, homologous structures, has traits of both types, same area/environment, molecular evidence,