07/21/2021 11:50 AM
Clarín.com
Dresses
Updated 07/21/2021 11:50 AM
The Xerces butterfly
is generally accepted as the first American insect species to be destroyed by urban development, but questions remain as to whether it was actually a species simply a sub-population of another common butterfly.
In a new study, researchers analyzed the DNA of a
93-year
-
old
Xerces blue specimen
from a museum collection and confirmed that it was a unique species, confirming that it is the first case in the United States of extinction of a man-made insect.
This Xerces blue butterfly was last seen flapping its iridescent wings in San Francisco
in the early 1940s.
In the new study, published in the journal
Biology Letters
, the researchers confirm that this butterfly is indeed extinct, and warn against that the conservation of insects is something we must take seriously.
"It's interesting to reaffirm that what people have been thinking for almost 100 years is true, that it was a species driven to extinction by human activities," says Felix Grewe, co-director of the Grainger Center for Bioinformatics at Field and lead author. from the Biology Letters article on the project.
A collection of the missing butterfly (Wikipedia).
"It has long been questioned whether the Xerces blue butterfly was really a distinct species or just a population of a widespread species called silver blue found throughout the west coast of North America," explains Corrie Moreau, director of the Collections of Insects from Cornell University, who began working on the study as a researcher at the Field Museum in Chicago.
"
The
widespread
silvery blue species
has many of the same traits (he continues). But we have multiple specimens in the Field Museum collections, and we have the Pritzker DNA lab and the Grainger Center for Bioinformatics that has the ability to sequence and analyzing a lot of DNA, so we decided to see if we could finally solve this question. "
The answer in a 1928 butterfly
To see if Xerces was truly a species of its own, Moreau and his colleagues turned to pinned butterfly specimens stored in drawers from the Field's insect collections.
With tweezers, he tore a small piece from the abdomen of a butterfly
collected in 1928.
"It was a nervous moment, because you want to protect as much as you can (remember). Taking the first steps and ripping off part of the abdomen was very stressful, but it was also somewhat exhilarating to know that we might be able to tackle
a question that has been going on for almost 100 years. no answer
and that cannot be answered in any other way. "
This is the first insect to be extinguished by human hands, 93 years ago in the US (Twitter).
Once the piece of the butterfly's body was recovered, the sample went to the Pritzker DNA Laboratory at the Field Museum, where the tissues were treated with chemicals to isolate the remaining DNA.
"DNA is a very stable molecule, it can last a long time after the cells in which it is stored have died," says Grewe.
Although DNA is a stable molecule, it breaks down over time.
However, there is DNA in every cell, and by comparing multiple strands of code, scientists can piece together what the original version looked like.
"It's like if you made a bunch of identical Lego structures and dropped them. The individual structures would be broken, but if you looked at them all together, you could figure out the shape of the original structure," Moreau says.
A notice on Twitter that regrets the disappearance.
Grewe, Moreau and their colleagues compared the genetic sequence of the Xerces blue butterfly with the
DNA of the
more widespread
silver blue butterfly
and found that the DNA of the Xerces blue was different, meaning it was a different species.
They maintain the ecosystem
The results of the study have broad implications.
"The Xerces blue butterfly is the most iconic insect for conservation because it
is the first North American insect that humans led to extinction
. There is an insect conservation society named after it," Moreau says.
"It is really terrible that we have driven something to extinction, but at the same time what we are saying is that everything we thought matches the DNA tests (he points out). If we had discovered that the blue Xerces was not really an extinct species, could potentially undermine conservation efforts. "
DNA analysis of extinct species sometimes invites the question of bringing them back, Jurassic Park-style, but Grewe and Moreau point out in their article that those efforts could be better spent protecting the species that still exist.
"Before we begin to strive for the resurrection, let's put that effort into protecting what is out there and learning from our past mistakes," says Grewe.
There are no longer any of these butterflies alive (Twitter).
Moreau agrees in pointing out the urgent need to protect insects.
"We are in the middle of what is called the insect apocalypse - massive declines in insects are being detected around the world (Moreau cautions). And while not all insects are as charismatic as the Xerces blue butterfly, they have huge implications on the functioning of ecosystems ".
As he notes, "many insects are actually the foundation of what
maintains the health of many of these ecosystems. They
aerate the soil, allowing plants to grow, and this feeds herbivores, which in turn feed carnivores. Every loss of an insect has a huge ripple effect on ecosystems, "he says.
In addition to the study's conservation implications, Grewe says the project highlights the importance of museum collections.
"When this butterfly was collected 93 years ago, nobody thought about sequencing its DNA. That is why we have to continue collecting, for researchers 100 years from now," he stresses.
Europa Press.
GML