Tuesday's course, Animal Taxonomy 1 !!

In animal taxonomy there are two ways to divide an animal into different classes. The old ones is with Apparent Differences method and  the newest ones with Reproductive Isolation method. Both method are can be used to indentify an animal classes.

Apparent Differences

Taxonomy method that use an animal apparent which can be seen or can be observed. Such as animal morphology , including external and internal morphology and animal physiology. Animal referred in one species if it has less of differences. There are some case that CAN NOT be solved with apparent differences method.  e.g. case between Alder flycatcher with Willow flycatcher.

Alder flycatcher (Empidonax alnorum )

Willow flycatcher (Empidonax traillii )

Both Alder flycatcher and Willow flycatcher are look like the same. Since they have the same morphology. They only can be distinguished by their sound (tweet). So they can’t be identified by apparent differences method easily. More description about their difference can be checked here

Reproductive Isolation

Taxonomy method which observe the results of breeding between two organisms.  An animal can be called in one species when it could produce fertile offsprings. Just like previous method There are some case that CAN NOT be solved with reproductive isolation method. e.g. case between Baltimore oriele with Bullock's oriele.

Baltimore oriole (Icterus galbula)

Bullock's oriole (Icterus bullockii)

Both Baltimore oriele and Bullock's oriele have different morphology but they can be bred and produce fertile offspring . So they can be identified easier than use reproductive isolation method. The reason why they could produce a fertile offsprings is because of their DNA and Molt timing.

• Molt Timing: Baltimore Orioles typically molt their plumage in summer after breeding but before migrating. Bullock's Orioles molt during migration and on their wintering grounds. One hybrid was found on its wintering grounds undergoing a molt, as Bullock's normally do, but it was molting out of brand new feathers! It was molting a second time after apparently already molting on its summer grounds. Molting takes a LOT of energy. Ornithologists believe that perhaps one reason why oriole hybrids don't increase is because they don't survive or reproduce as well as pure Baltimore and Bullock's Orioles do thanks to that wasted energy molting twice a year
• DNA: Recent studies of mitochondrial DNA (the DNA in the mitochondria of cells, which many scientists use to show relationships among various animals) show the Baltimore and Bullock's Orioles are not even very closely related! The Baltimore Oriole shows more genetic similarities to the Altamira Oriole (which lives in Mexico, northern Central America, and a tiny part of Texas) and especially to the Black-backed Oriole (from Mexico). Bullock's Oriole is more closely related to the Streak-backed Oriole (from Central America, Mexico, and rarely southern Arizona and California).

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Generaly, from today's lecture I catch a conclusion that Reproductive Isolation method is more accurate than the Apparent Differences method to identify the animal origin of the most species. Even In some case, there is a miss direction between reproduction isolation and apparent differences. 

Thank you so much for wasting your time here to read my post. I really appreciated your presence.
See yaa next time, fellas~ ^_^