Module 11 Prompt:
In the book, it talks about how hybridization from secondary
contact can lead to homoploid hybrid speciation. An example of this is the
formation of a new species that are isolated reproductively from both parents
but without any change in the ploidy levels. This isn’t very common but is seen
in insects, amphibians, fishes, and birds. We even see them in marine mammals as
well. One that most people would be familiar with though is the famous Darwin’s
finches in the Galapagos Islands. The hybridization between the mating of the
male Espanola cactus finch and the female medium ground finches from different
islands is a classic example. The hybridization event produced a new lineage
that became endemic to the Daphne Major Island. The lineage is known as the “big
bird lineage” because of the size of the birds! They even caused the new lineage
to become isolated reproductively from other species that occurred naturally on
the island ultimately.
The process of speciation usually takes some time but in the
case of the “big birds” finches, it happened very quickly. According to an
article in futurity, speciation happened in just two generations….TWO! I
don’t know about y’all but that is very hard to wrap around my head right now. It
is safe to say Charles Darwin might have had a heart attack had he seen this
happen way back when. These birds have their own beak morphology as well which
makes them different from the other finches. I think this is a great example of
hybridization because we’ve already discussed Darwin’s finches and it’s cool to
add a new concept to talk about with these birds.
It's so crazy that that only took two generations! It's wild how everything we learn about evolution seems to always have an asterisk with an exception.
ReplyDeleteI am also amazed at the fact the new finch species arose after only two generations. There must have been some sort of physical separation of the hybrid from the other species to prevent them from breeding further and creating that reproductive isolation quickly. I was also surprised, although not as intensely, that the new species was fertile right off the bat. Oftentimes, hybrids offspring are sterile.
ReplyDeleteThanks for sharing!