BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: rescuefromextinction

Tree Lobsters Are Back!

Image result for Stick insects Tree lobsters Lord Howe

Lord Howe Tree Lobster

Tree Lobsters are actually not lobsters at all. Nor are they crustaceans.  They are actually just insects with a similarly shaped exoskeleton. But that’s not what makes them interesting. What does, is that Tree Lobsters have seemingly come back from extinction.

The Species, originally from the Lord Howe Island in the Tasman Sea between Australia and New Zealand, went extinct during the 1920’s due to becoming the main food source for an invasive rat species that came onto the island. The Tree Lobsters were only formally declared extinct in 1960 though. Since then scientist had pretty much forgotten about them.

Image result for Stick insects Tree lobsters Lord Howe

Ball’s Pyramid Stick Insect

Thus, when scientists found a small group of stick insects similar to Lord Howe Tree Lobster’s on Ball’s Pyramid, a volcanic stack 12 miles away from Lord Howe Island, in 2001, they were quite surprised. The Ball’s Pyramid stick insects were skinnier and darker but scientists were still hopeful the newly discovered insects were, in fact, the same species as the extinct Lord Howe Tree Lobsters. Scientists tested the genes of the stick bugs from Ball’s Pyramid with genes extracted from preserved Lord Howe Tree Lobsters and found out that despite some morphological variance, they are still the same species. They speculate that diet, age, and environment had caused the Ball’s Pyramid Stick Insects to look a little different. How the species got to the volcanic stack is still a mystery as the insects cannot swim but they infer that they had been carried over by birds.

The newly discovered Tree Lobsters are now being bred at the Melbourne Zoo and elsewhere in an attempt to reintroduce the species to Lord Howe Island. However, the invasive rat species on Lord Howe Island still remains a problem as it threatens the lives of over 70 different native species. In order to successfully reintroduce the Tree Lobsters back to Lord Howe, the rat problem needs to be taken care of first.

The Immaculate Conceptions: Smalltooth Sawfish Experiencing Virgin Births

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From Flickr

Chances are you have never heard of the Smalltooth Sawfish, an endangered species most commonly found off the western cost of Florida. These creatures grow to be as long as 25 feet, but their is more that is impressive about these fish than their shockingly large size. Recent studies have shown that around 3% of Smalltooth reproduce asexually, a virgin birth. This is the first hard evidence that birth of parthenogens, offspring born of asexual reproduction, happens in nature. This speaks to the adaptability of life, scientist Demian Chapman, says that it makes sense that endangered species would be the ones most commonly reproducing asexually, “that life finds a way”. This discovery was made when researchers tagged and sampled DNA from around 190 Sawfish, which lead to the discovery of 7 parthenogens.

Scientist hypothesize that during meiosis, sex cells fused together to form offspring. Incredibly, all seven of the parthenogens are fully healthy and functioning, and seem to be viable sexual partners. This “suggests that parthenogens are not a dead end” that this “extreme form of inbreeding” does not lead to any serious defects. Unfortunately, Smalltooth Sawfish are on the verge of extinction due to human interference in their natural habitat. Although the Sawfish are able to reproduce asexually, the occurrence rate is too small to sustain a viable number of Sawfish to save them from extinction, but raising awareness of the issue could be the key to saving these magnificent creatures.

 

Original Article

Sawfish Extinction

More Examples of Parthenogens in Nature

Birds and Migration: More Than Just the “V-Formation”

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For as long as we can remember, we have known that many species of birds migrate south during the winter, in a “V-formation.” Recent studies by ecophysiologist Steven Portugal have suggested that the classic formation helps birds to conserve the most energy possible. His investigation involved researching the Northern Bald Ibis, a bird that was extinct in Europe for around 400 years. Johannes Fritz has been working tirelessly to bring the Northern Bald Ibis out of extinction, by pioneering an human-led migration throughout Europe, for the past 12 years. (To discover more about these birds, and their emergence from extinction in Europe, check out this site.)

Through his studies, Steven Portugal has identified that his hypothesis was correct; the “V-Formation” does, in-fact, help a flock of birds conserve the most energy as well as “the birds’ formation fitted the theoretical predictions of aerodynamics.” The birds synchronize their flapping when they experience turbulence. He also found that the birds break their arrangement to those of “less-optimal positions.” This includes, birds going one-behind-the-other, and changing their wing-flapping patterns. This is all believed to prevent downwash, which is “the downward deflection of of an airflow,” as defined by the dictionary.

Thanks to the work done by Steven Portugal, Johannes Fritz and their respective teams, we have come much closer to discovering “the why” in bird-behavioral patterns, namely their flock formation during migration.

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