Did
you know that whales haven’t always been so huge? A study by Nicholas
Pyenson, a paleobiologist with Smithsonian’s Museum of Natural History,
determined that ancient whales were significantly smaller than today’s
behemoths. Read more ... https://www.smithsonianmag.com/smart-news/researchers-figure-out-why-whales-got-so-gosh-darned-big-180963441/
What
I enjoyed about this article is that, instead of picking an answer from
a dartboard of possibilities, Pyenson’s team calculated the length of
extinct whale species from the size of their fossilized skulls. Those
old whales were still very large, but they didn’t get massive (over 33
feet long) until a relatively few years ago — 4.5 million really, but
that’s only 10% of the time that whale species have existed altogether.
A
likely scenario for their more-recent gigantism may be due to climactic
change, another study points out. An oncoming ice age may have forced
whales to migrate further between food sources. They’d have to get
chubby in order to save enough energy to make long-distance journeys.
It’s another hypothesis to tack onto the dartboard of theories.
I
wonder how this conjecture applies to gigantism on land? It doesn’t
seem likely that all the largest of ancient reptiles and dinosaurs
became freakishly huge because their favorite plants just happened to be
thousands of miles apart, does it? In the vast oceans, blending food
sources was relatively an easy process, but patches of krill, for
example, could be separated due to concentrations of foods into
particular areas.
Sure,
migratory patterns exist on land today as well, but the vast majority
of migrating animals are tiny when compared to many of the beasts of the
past.
The
article further points out that the argument for gigantism occurred as a
means of avoiding predators doesn’t appear to hold true for whales.
Whales were becoming larger around the time their potential predators
were becoming extinct. Something doesn't add up. It would seem that there
isn’t one tidy answer for gigantism.
Have a nice day.
-R.J.
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