TEXTO:
Jurassic Park’s iconic image of a fossilized blood
filled mosquito was thought to be fiction — until now. For
the first time, researchers have identified a fossil of a
female mosquito with traces of blood in its engorged
[5] abdomen. A team led by Dale Greenwalt at the US
National Museum of Natural History in Washington DC
reported the fossil discovery in Proceedings of the
National Academy of Sciences.
Although scientists have found fossils of suspected
[10] blood-sucking insects, the creatures’ feeding habits have
mostly been inferred from their anatomy or the presence
of blood-borne parasites in their guts. But Greenwalt’s
fossilized mosquito contains molecules that provide strong
evidence of blood-feeding among ancient insects back
[15] to 46 million years ago. It is a fortunate find. “The abdomen
of a blood-engorged mosquito is like a balloon ready to
burst. It is very fragile,” says Greenwalt. “The chances
that it wouldn’t have disintegrated prior to fossilization
were infinitesimally small.”
[20] The insect was found not in amber, as depicted
in Jurassic Park, but in shale rock sediments from
Montana. After 46 million years, any DNA would be long
degraded, but other molecules can survive. Greenwalt’s
team showed that the insect’s abdomen still contains
[25] large traces of iron and the organic molecule porphyrin
— both constituents of hemoglobin, the oxygen-carrying
pigment found in vertebrate blood. These molecules were
either rare or absent in the abdomen of a fossilized male
mosquito (which does not drink blood) of the same age,
[30] found at the same location. “This shows that details of a
blood-sucking mosquito can be nicely preserved in a
medium other than amber,” says George Poinar, who
studies fossilized insects at Oregon State University in
Corvallis. “It also shows that some porphyrin compounds
[35] in vertebrate blood can survive under the right conditions
for millions of years.”
YOUNG. Ed. Disponível em: . Acesso em: 24 jun. 2016.
As far as the fossilized mosquito is concerned, it’s correct to say that
