It would be hard, looking at whales and elephants, to see how they could exist in any but the most ancient and distant of branches together, but the history of their divergence is actually much more recent than it seems. Cetaceans (whales and dolphins), pachederms (wooly mammoths and elephants) and serenia (manatees, dugongs) are all part of a much larger subclass of mammals called ungulates.
The name ungulate literally means “toe walkers,” and refers to the species of life that the cooler, drier climates of the post-dinosaur world gave rise to. As grasslands and wide open spaces began appearing, some mammals began walking higher off the ground with their legs directly under them. This is as distinct from Dimetrodon and other mammal-like dinos whose legs were beside the animal.
The early era of ungulates is the era of the “mega-fauna.” These huge species of plains grazing animals included the Uintatherium, which was a species that looked like the modern rhinoceros, which roamed the plains of Wyoming 52 million years ago.
Eventually, some of these ungulate species grew thicker toe claws which eventually became hooves. Horses, goats and the other hooved animals descend from this line.
Still others never developed hooves, but retained the original digits. Of these, some evolved into the pachyderms like great wooly mammoths and elephants. Others returned to the sea and became seals, walruses, manatees and whales. In fact, close inspection of some species of whale’s fins reveals depressions where the old “toe walker” claws still remain.
View of Durand Park Beach, courtesy of mjernisse on Flickr.com
Seems like every year, at least once, the Durand-Eastman Park beach closes. This same pattern is echoed around the lake for a variety of reasons, but the biggest and most dangerous reason is the presence of an algae bloom. Algae blooms happen when, for one reason or another, large quantities of algae are produced in a local area. Algae can starve the water of oxygen and poison it for swimmers and wildlife, alike. Minor blooms such as those that close beaches might get you sick. An algae bloom run amok could spell the end of countless species within an ecosystem.
But Dr. Andre Hudson, a professor at RIT, may have found the beginnings of a solution to the problem. Dr. Hudson discovered a means by which the normal photosynthetic process in algae might be short-circuited, eliminating the algae while leaving other life in the same ecosystem intact.
The key to the discovery actually is a key of sorts, specifically the enzyme algae use to produce a protein called Lysine. An enzyme is a molecule produced by a living organism that facilitates and speeds up specific chemical reactions in the presence of another chemical, generically referred to as a “substrate.” Like a lock and key, the enzyme binds to the substrate and in this case, causes lysine to be produced.
Lysine molecule
The algae rely on lysine to continue to survive and reproduce. If a chemical were introduced into their habitat that bound to the enzyme as well or better than the algae’s normal substrate, but did not allow the same chemical reaction to occur, the algae’s ability to produce lysine would be severely inhibited. In short, no more algae.
But lysine is a basic building block of life everywhere on Earth: not just algae but *all* photosynthesizing organisms – plants, algae and some bacteria – produce it. Those of us not fortunate enough to be photoautotrophs rely on eating those primary producers to get it for ourselves. So, how do we not have a massive, pan-species death chemical on our hands, capable of destroying plant life directly and starving animals, casting the entire ecosystem into barren oblivion? That would suck.
The answer is, again, the enzyme: now that Dr. Hudson has identified the enzyme itself, other researchers can pick up the ball and analyze the enzyme as it appears in a variety of species. Enzymes being highly complex structures, chances are that two different species of algae – to say nothing of other plants – will have completely differently-organized enzymes that perform the same function. Every organism is likely to be highly-specialized.
So our anti-lysine chemical could be tailor-made to hit exactly the targets we wish to eliminate. No death for the innocent, in other words.
This specialized means of eliminating photosynthesizers means that the discovery that could end irritating beach closures could have far more widely-spread effects. Any kind of aquaria – from pools to aquariums to drinking water – could be purified in this fashion. Other non-algae plant life could also be targeted, even pathogens that might otherwise be treated by penicillin.
In fact, with the enzyme now identified, the future of anti-algae efforts may not even rely on a synthetic chemical at all: the only requirement is that the chemical be one which fits as well or better with the lysine enzyme, which we may find occurs in nature. It may be just these kinds of discoveries that enhance our ability to be the stewards of the Earth that our Earth requires.
Adherents to one of the more exotic (literally) theories on the origins of life has just gotten a boost of confidence, based on the latest @NASA research:
Scientists have detected the building blocks of DNA in meteorites since the 1960s, but were unsure whether they were created in space or resulted from contamination by terrestrial life. The latest research indicates certain nucleobases — the building blocks of our genetic material — reach the Earth on meteorites in greater diversity and quantity than previously thought.
The theory that life was “seeded” onto the Earth from meteorites crashing onto its surface is called Panspermia. Like the article notes, this theory has been in circulation and widely supported since the 60’s when the discovery of DNA building blocks was first made.
But the theory of Panspermia has always been hampered by the prospect of contamination: since the meteorites we observe are already on the planet, the chemicals that spark the debate might just have seeped into the rock once the meteorite was on Earth. These rocks are not, after all, recent visitors.
The current research was conducted on meteorite fragments found in the Antarctic. The scientists found that many different molecules, very similar to DNA’s base, are present in the rock. Despite the similarity, not all the chemicals found in the meteorites are commonly employed in biology.
But significantly, the ice surrounding the meteorite did not have the same chemicals present. That suggests that the meteorite in question was forming new chemicals prior to its arrival, rather than simply holding onto debris from its new home.
