Evolutionary Anachronisms in The Western Palearctic – Part I: Puzzling Pomes
In their 1982 paper Neotropical Anachronisms: The Fruits the Gomphotheres Ate, Daniel H. Janzen and Paul S. Martin defined it as a trait of a plant that is inexplicable unless seen in the backdrop of its evolutionary past. For instance, Gymnocladus dioicus, a tree in the legume plant family Fabaceae that is native to the eastern United States, produces seed pods that are poisonous to mammals, unbreakable to rodents and impervious to water, yet depend on all of these for dispersal since the seeds, the largest in the continental United States, are too heavy to be carried by wind anywhere far. As a result, each year the parent tree will produce pods that fall to the ground, where they slowly decompose over the years, even in seemingly natural habitat. This is odd because the fruit of any plant is always intended as a diaspore. Plants have outbid each other over millions of years in attempts to produce the most sophisticated designs that will allow their unborn offspring to travel and germinate a preferably long distance away from the parent. So, if the Kentucky coffeetree, as it is also called, fails so miserably at dispersing seeds away from the parent tree, despite an elaborate diaspore, one is compelled to ask, why?.
The History of the Decline and Fall of the Great Auk
The extinction of species has long captivated the curiosity of scientists and nature enthusiasts alike. Within the realm of vanished creatures, the great auk stands as a prominent figure. As the only flightless bird in the North Atlantic, the great auk (Pinguinus impennis) held a unique position as the largest member of the Alcidae family, commonly known as auks. This goose-sized seabird has left an indelible mark on our natural history
Isles of the Tasman Sea – Part II: Norfolk Island
Norfolk Island offers an interesting juxtaposition to Lord Howe Island, as it contains a very similar faunal guild, but the extent and circumstances of its extinctions are somewhat different.
Isles of the Tasman Sea – Part I: Lord Howe
600km off the east coast of Australia, amidst the Tasman Sea, sits a tiny archipelago – the only specks of land for a hundred leagues. The Lord Howe Island Group. Today the entire archipelago is considered UNESCO world heritage due to its interesting collection of flora and fauna with high rates of endemism. Unfortunately, as is also often the case with islands, this diversity has become much diminished in historical times.
Unwelcome Guests – Coextinction of Parasites
In biology, parasitism is a form of symbiosis, a close association between species, in which one species (the parasite) exploits another (the host) for its own benefit. This aspect of harm is what separates parasitism from other symbioses, such as commensalism, in which one species sees gains while other isn’t affected. Most parasites depend entirely on their hosts for nourishment and/or habitat, and so they become intimately tied in an evolutionary context. This host dependence often leads to extreme adaptations and body plans tailored to surviving on – or in – another organism’s body.
Islands - Socotra
Isolated for 20 million years, Socotra is a world apart. It is home to numerous birds and reptiles found nowhere else, as well as a host of plants, so bizarre as to look almost alien. And yet, Socotra is in decline.
Passenger Pigeons: Stewards of the Hardwood Forests
Passenger Pigeons were the most common bird in North America at the time of European settlement but were wiped out within a few centuries. The species shaped the landscapes and ecosystems within its range by virtue of its sheer abundance and unique behavior. Most affected were the hardwood forests of the Northern United States, where billions of pigeons would congregate annually to breed and inflict massive changes on their breeding grounds.
The European Wild Horse
The horse is one of man’s most important domestic animals. Just like cattle, horses descended from a once widespread wildtype that is now extinct because of human influence. The western subspecies of the wild horse, Equus ferus ferus, had a range from the Iberian peninsular to the western Eurasian steppe, where the horse was most likely domesticated. Although the domestic horse is well-known to us, the wild form is kind of elusive – it is not certain when it died out, how common it was, what it looked like, and there is not even a consensus on how to name this animal.
Wildfowl Extinctions
Wildfowl are amongst the most prolific bird groups and have reached every part of the planet, including remote islands. The group has not been spared casualties during the Holocene extinctions, and a clear pattern emerges when extinction dates are compared to the time of human arrival, though the mechanism remains less clear.