An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures.
true / false.

True

Explanation:

Apparently different organisms such as hummingbirds, humans and whales, have similar skeletal structures may have similar skeletal structures. It seems impossible, but it is entirely possible to remember that different organisms may have had the same common ancestor, which explains the presence of similar skeletal structures.

Common ancestor is a species that, through the process of descent with modification, gives rise to new species. The evolutionary relationships of organisms can be represented by phylogenetic trees (or phylogenies), which are branched tree-shaped diagrams showing ancestral relationships between species. In phylogenies, each branch represents a particular species or group (extinct or current) and each branch point an ancestor.

glacial erosion, the picking up and movement of earth beneath a glacier, is also referred to as plucking. erosion and transportation of individual pieces of bedrock, especially large "joint block occur as a result of this glacial erosion. plucking is type of erosion in which rocks become frozen into the bottom and sides of the glacier.as the glacier moves downhill it 'plucks' the rocks frozen into the glacier from the ground.

c.           is the correct answer