Question

Dugongs, bats, horses, voles,and primates all posses the same three forelimb bones (humerus,radius, and ulna) by virtue of shared ancestry. This three bone pattern is therefor a homologous character.

1. true
2. false

Answer 1

The statement that the limb bones in question are homologous characters across various species due to shared ancestry is true. These homologous structures, while serving different functions, underline their common evolutionary past.

Step-by-step explanation:

The statement that dugongs, bats, horses, voles, and primates all possess the same three forelimb bones (humerus, radius, and ulna) by virtue of shared ancestry, and therefore this three bone pattern is a homologous character, is true. These structures are considered homologous because they were inherited from a common ancestor, despite these bones potentially serving different functions in each species. For example, bats use their forelimbs for flying, while horses use them for running. The commonality of these bone structures across various species supports the theory of evolution, indicating these organisms share a common evolutionary past.

Figure 18.7 in the provided reference materials illustrates the similar construction of appendages in humans, dogs, birds, and whales, further emphasizing their common ancestry. Similarly, Figure 20.7 highlights that bat and bird wings are also homologous structures, reinforcing the concept that these animals share a common evolutionary history.