1.
A.
Leatherback sea turtles and desert tortoises, although often misunderstood,
are both reptilian, not amphibian. Many
turtles have webbed feet and their bodies are leaner than that of a tortoise,
allowing them to glide through the water easily. Tortoises usually live in hot, dry climates,
and have thick, stumpy legs that are perfect for digging through desert sand.
Both tortoises and turtles share a homologous trait: their shell.
B. Turtles
have a range of shell density and textures that vary due to adaptations
relating to protection and mobility. The
leatherback sea turtle, for example, has a smooth, skin-textured shell that has
a network of bones supporting it. This
allows the turtle to dive at greater depths than other types of turtles whose
heavy, bony shells would crack at similar pressure. On the other hand, the desert tortoise has an
extremely thick shell that helps to protect it from not only local predators,
but also from extreme climate changes.
Although similar in appearance, the shell of each species has adapted to
encourage their survival within their respective climates.
C. Turtles and tortoises both share common
ancestry, belonging to the Testudine Order, with fossils being found during the
Triassic period.
2. A. The
narwhal is a whale with a long horn (similar to a tusk) attached to the tip of
his “forehead”, and the black tail deer has antlers. In both of these animals,
these horns are intended to attract a mate.
B. The male narwhal has a horn that
supposedly (scientists haven’t come up with any other suggestions-it doesn’t
function as a spear or tool of aggression) is meant to attract female
narwhals. This is very similar to the
tusks of and elephant, or, for use in this scenario, to compare to the antlers
of a deer. Antlers, just like the male
peacock’s showy feathers, are meant to gain attention and favor. Based on the
studies of narwhal experts, the narwhal horn is identical in function and
attracts a mate. They have no recent
common ancestor, many scientists believe that they both stem from an order
known as Cetartiodactyla, which
includes hooved mammals, and whales.
C. In the male deer, antlers also demonstrate dominance among the non-alphas
in their groupings. Scientists have not
been able to demonstrate the function of a narwhal’s horn for anything other
than sexual attraction. I think that the
common ancestor may not actually have possessed this trait, as, at least in the
deer’s case, it seems to have been a much more recent adaptation.
