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| Archipelago of Fernando de Noronha. |
I'll start posting something in my comfortable zone. Let's talk about Fernando de Noronha and the impacts of non-native species there. Fernando de Noronha is a group of islands with no more than 2 thousand inhabitants and one of the most touristic places in the world.
- What happened in Noronha?
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Cranium of Noronhomys vespuccii. |
In 1503, when the Italian explorer Amerigo Vespucci arrived in Noronha he may have seen a species that today is known as Noronhomys vespuccii, a enormous species of rat that today are extinct. After the first explorers introduced Mus musculus and Felis catus the population of Vespucci's Rat decreased drastically, years later with the introduction of Rattus rattus the competition became too wild and this species disappeared.
The fossils of this species were found in 1973 and described by Carleton and Olson in 1999. The evolutionary history of this animals suggest that their ancestors were semi-aquatic animals and Carleton and Olson (1999) suggest that the characteristics were lost when the progenitors of the Vespucci's Rat became stranded on a small oceanic island. This new characteristic probably appeared because of the natural selection in a long process (maybe million of years), but the presence of invasive species destroyed it in centuries.
To sum up, the anthropogenic alteration is cruel mainly to native island species as Noronhomys vespuccii. Now, the effects of the most invasive species in the world, known as Homo sapiens is incalculable and the alterations in fragile ecosystems is deteriorating more and more the environment.
Work cited (description of new genus and species):
I think it’s great you used some pictures to help put the topic in context. You mention that some characteristics were lost when these rats became stranded, and then you mention a “new” characteristic. However, you don’t explain what this new characteristic actually was? I’m interested in learning about different and exciting examples within this topic!
ReplyDeleteHey Tasmin, thank you,
DeleteCarleton and Olson suggest that the ancestors of these rats were semi-aquatic rodents, to be more specific from the Clade Pseudoryzomys that is represented basically by semi-aquatic rodents.
Based on morphometric results and anatomical details of the pelvic limb they suggest that Noronhomys was not a semiaquatic.
Also, It is hypothesized that such aquatic skeletomuscular adaptations were lost (reversed) when their ancestors became stranded on a small oceanic island where aquatic habits were scarce or absent.
So, we could conclude that bones and muscles become adapted to new environment (NATURAL SELECTION).