1. Both whales and kangaroos are mammals and share the homolog of hind legs. Hind
legs are the rear limbs of quadrupeds.
Kangaroos hind legs have developed
into quite strong features as they use them to hop around at speeds up to
40mph. Kangaroos hind legs are very large in size and structure. As for Whales,
their hind legs are no longer visible but when looking at the skeleton the
bones and pelvic girdle are still there, showing that at one time whales walked
on hind legs but have evolved into no longer needing them as they spend their
life in oceans. Despite the whales not having visible hind legs and the
kangaroos have powerful large legs their bone structure still shows similarities
to the trait.
Generally the common ancestor of
kangaroos and whales was a mammal, as all mammals show to still have hind legs or
history of them the ancestor must have also had this trait. Even if you look
further down the ancestors, you find that reptiles, which share a commons ancestor
with mammals and have species with hind legs and species like snakes that have
evolved into not needing their hind legs.
ANALOGY
1. Sharks and whales both have pectoral
fins and some whales also have dorsal fins but these traits are analogous.
These fins help them maneuver through water with more agility. The shapes while being slightly different in exact outlines still look very similar and work in the same way as the pectoral fins share the same movement.
For the size of a whale
were it not for the pectoral fins it would be extremely slow and as for the
shark being a predator it needs to be as agile as possible to catch it prey. If
you do go far back enough I do believe that the common ancestor would it be a ocean
living specie would have had this trait. The traits are not genetically related
because whales are mammal and the pectoral fin is full of bones similar to that
of a hand. As for the shark, it does not have a real bone structure as its body
is mostly cartilage Whales also being mammals are warm blooded. Marine mammals evolved
from being on land to water mammals and in this evolution in order to survive
grew fins to better fit into the environment through convergent evolution.
I really like the animals you picked! I struggled at first trying to come up with these traits, but I remember the weird "Left over" bones in whales from high school or something. I also appreciate that you chose to compare the whale to the Kangaroo because of the clear difference between how each animal uses those traits. It really makes everything more interesting!
ReplyDeleteGreat and daring homologs! These are two drastically different traits and you did a good job of explaining their functional/structural differences. Good follow-up with the explanation of common ancestry.
ReplyDeleteVery good analogous pairing.
"Marine mammals evolved from being on land to water mammals and in this evolution in order to survive grew fins to better fit into the environment through convergent evolution."
That is precisely the information I was looking for. Well done.