Species Isolation and the Creation of New Species/subspecies from Interbreeding

Taking away what we discussed in class, it seems that we can assume there is no true “origin” of a species, since everything seems derivative of another. An interesting example of what we can see from our own recent origins is our link to the Y-Chromosomal Adam, which did not originate from one individual but from “different species through interbreeding which dates Adam to be twice as old as previously thought.” The question that the findings surface is to “what extend did our humans precursors interbreed with their closest relatives”, going back even further than 200,000 years? (source) We are our own greatest mystery!

Arabian Sea Humpback whale photographed in Dhofar, Southern Oman. Image credit: T. Collins / D. MacDonald.

Arabian Sea Humpback whale photographed in Dhofar, Southern Oman. Image credit: T. Collins /D. MacDonald.

A related story I came across last week on reddit.com referenced this article (article) about humpback whales isolated in the Arabian Sea for 70,000 years, causing them to also be the most genetically distinct Humpbacks, as well as the most isolated whale population in the world. What caused this isolated behavior in a typically migratory animal? Relative to the finches of the Galapagos, diet and environment had an adverse effect on their adaptations and mutations for their current states. The whales of the Arabian Sea are thought to have been affected by glacial patterns as well as monsoon activity. They have the lowest level of genetic diversity of all humpback whales due to this isolation, as well as “bottlenecks” in their breeding periods thought to have been caused by whaling. It seems like the finches evolved more positively in relation to their environmental factors and helped them to thrive, compared to the Arabian whales who are low in number and do not have any particular adaptations to better help them in their environment, but rather as a result of population and environmental limitation.

It would be interesting to see comparisons/contrasts between animals that have been genetically diversifies positively/negatively according to their environment.

-Jessica C.

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One thought on “Species Isolation and the Creation of New Species/subspecies from Interbreeding

  1. Thank god someone actually understands this stuff. Now we aren’t linked through a chromosomal Adam but a chromosomal Eve, through genetics you always follow the X line because every individual has at least one X chromosome.

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