An Ocean Census
Most people will recognize the two-part naming system for animals, with a generic name and species name. Homo sapiens, or human beings, is the most parochial example. Fewer people will remember that this naming system was developed by Carl Linnaeus, a Swedish naturalist, in the 1700s, as a way to categorize all life. With a few modifications, Linnaeus’ system, and mission, are with us today.
Here’s a link to an interesting article from Yahoo News:
The article is concerned with two things, both of interest to animal lovers everywhere:
First, and important more as a piece of scientific history, is a tour of Linnaeus’ copy of his own Systema Naturae, and second, and more important for nature lovers, is a description of an ongoing, extrememly ambitious, project to finish Linnaeus’ catalog.
Biologists have been working on cataloging species since Linnaeus’ time, or even a little earlier. On one level, this deceptively simple task (find, name, and describe each animal) looks easy; after all, once an animal is known, you don’t have to record it again.
But, like life, the natural world just isn’t that easy. Many species live in hard to reach places; oceanographers estimate that less than 5% of the world’s ocean area has been thoroughly explored, and at best, about 10% of marine life is known to science. The estimates for the number of insect species (of which about 1 million are known) that exist on Earth range from 2 to 10 million; the majority live in the world’s tropical rainforests, which are almost as little known as the ocean depths. It’ll be a long time before we have a truly complete knowledge of our planet.
As Robert Browning say, “Ah, but a man’s reach should exceed his grasp, or what’s a heaven for?”
Infestations
I threw away a bag of rice today. I wouldn’t do that normally, because I love rice, but when I opened this bag of wild rice, some of the black grains got up and walked away.
The whole bag was infested with some sort of little bug. I wasn’t going to eat it.
Now, if you’ve been reading this blog, you know that I am fascinated by animals, of all sorts. Bugs, however, I just don’t like. Never have. I know that there are some people who keep large spiders, or giant hissing cockroaches, as pets, but I’m not one of them. I know, from my studies, that the Arthropoda are a vital part of the world’s ecosystems, but that doesn’t mean that I want them in my house.
Or in my rice.
I don’t know what type of insect was in the bag. They were black, and smaller than a grain of rice, and fairly fast moving. I know that they can subsist inside a plastic bag, with no water, eating nothing but uncooked dry rice. Sounds pretty bland, as far as existence goes, but the animal world does contain all types….
But not all of them are types that we want to find in our homes, or in our pantries, or in our food. I’m going to go now, and head over to the store to pick up some good tupperware/rubbermaid type containers for better long-term, bug free, food storage.
The Little Lizard that Can
I was in a pet shop the other day, and saw a neat looking lizard. It wasn’t one I’d seen before, although I’d heard of them, and I found it interesting. It was a leopard gecko.
Leopard gecko’s are native to the deser regions of northwestern India, Pakistan, and Afghanistan. That region’s been in the news lately, but that’s not why these lizards are popular among herpetology fans. They are popular because they have near-perfect pet lizard attributes.
To start with, they are small. Adults get to be about 5 inches long. This makes them manageable, especially when compard with constrictor snakes or monitor lizards. In addition to their small size, they are also very tough little critters, able to tolerate cool temperatures or changes in humidity better than many other small reptiles. Both of these factors make them excellent choices for beginner reptile keepers.
Even more important, though, from the keepers’ perspective, is that these little geckos are not the kind of gecko that can walk up walls. Their toes end in small claws, rather than the clingy pads of house-geckos. Leopard geckos are terrestrial, which means that they will stay in a glass terrarium.
Their environmental requirements are modest: a grainy sustrate, a wide, shallow water dish, and a place to hide will cover the basics, and a heat lamp and heat pad will help keep a constant temperature near 80 F. For food, these lizards will require live insects. They are insect predators in their natural environment, and enjoy the hunt. Crickets, meal worms, and wax worms will suffice for a diet. They’ll even go after, and sometimes catch, the moths that wax worms mature into.
I got most of this info from the proprietor at the pet shop. Honestly, I wouldn’t take a reptile pet, myself. Even the easy lizards, like leopard geckos, require some specialized care and handling, I don’t recommend that anyone take on a pet that they aren’t prepared to provide the absolute best possible situation.
They Ran Over a Whale
This animal’s no longer with us, but strange things are still happening to it, anyway.
I am always on the lookout for interesting stories about animals, as you know, but I am also on the lookout for just plain strange news articles, too. This time, I have managed to find both at once…
I found this article on Yahoo News. Here’s the link:
http://news.yahoo.com/s/afp/20070826/sc_afp/egyptarchaeology_070826175713
European diplomats in four-wheel drive cars have caused millions of dollars worth of damage to a fossilised whale lying for millions of years in the Egyptian desert, a security source said on Sunday….
Two cars drove into the protected area on Friday and then refused to stop when asked to do so by wardens who nevertheless got the vehicles’ registration numbers which the source said were from “a European country….”
The site, known as Wadi Hitan (Whale Valley), was home to whales around 40 million years ago when the area was ocean. It is a UNESCO World Heritage site and home to hundreds of of whale fossils.
Now, I am all for protecting nature, and maintaining the integrity of a scientific find, so I have some questions about this incident:
First, why are these fossils still in the ground? If they are so valuable, and so accessible, why hasn’t Egypt arranged or allowed an expedition to excavate the fossils? After all, the value of a fossil is scientific, and that value is nil while the fossils are in the ground, where they cannot be examined or studied.
Second, why, as the article said, was the damage more than 10 million dollars? How can there be 10 million dollars worth of damage to a fossil that has yet to be studied?
Value comes from two sources: what people will pay for an object, and what people want for an object. What we’re seeing here is only one of those values, because clearly, the paleontological establishment (for whom these fossils are especially valuable) is not willing to pay Egypt’s price for them. Somehow, I think that the number “10 million dollars” is more for politics than anything else.
In any case, it is intersting to note that Egypt’s whale fossils are an amazing look at the early history of the whale lineage. Fossil evidence has shown that whales returned to the sea (their ancestors were terrestrial predators called mesonochids) on the southern coast of what’s now Pakistan, some 50 to 60 million years ago, before India collided with Asia.
The Egyptian fossils are close to this in both time and space, and therefore give a good look at the earliest, fully marine, whales.
I would say that gives the fossils value, but only if they gotten out of the ground.
A Lobster Story
There’s more to lobsters than meets the eye.
My wife loves lobsters. She says that there’s no better eating than a good
lobster tail. You can imagine her discomfiture, then, when I explained to her
that, as arthropods, lobsters are closely related to the cockroaches she smashes
so readily.
Actually, lobsters are crustaceans, and are more closely related to crabs,
shrimp, and terrestrial isopods than they are to insects. All of these groups
fall into the arthropod phylum, however, which accounts for about three-quarters
of all named animal species. Isopods are the little roly-poly bugs that kids
like to poke until they curl up in a ball, and can be flicked across the
floor.
Lobsters come in several varietiesl; it’s fair to say, actually, that there
is no such thing as “the lobster.” The big, clawed Maine lobsters that most of
us think of when we hear the word “lobster” is just one species. It’s native to
the North Atlantic Ocean, where it lives in the intertidal zone along the
shore. Basically, the Maine lobster is a very large, saltwater version of the
common crayfish.
Other lobsters are more closely related to shrimp. The spiny lobster of the
Pacific Ocean is one of these. Spiny lobsters are far larger than a shrimp,
although they do not get as big as Maine lobsters, and they do not have the
large claws.
All lobster species are either predators or scavengers. There is very little
that they cannot eat, and they are a terror to the small invertebrate animals of
near shore waters.
Here is a very interesting news article, off of Yahoo, about a marine
biologist from Maine, who’s mader lobsters her life’s work:
http://news.yahoo.com/s/ap/20070714/ap_on_sc/lobster_researcher
Enjoy!
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Woolly Mammoths
An intereseting discovery from Siberia: a frozen mammoth, with potentially
intact DNA.
We’ve all heard of woolly mammoths. They were close relatives of elephants,
but unlike modern elephants, woolly mammoths were heavily furred and well
adapted for live in cold climates. The lived in the Northern Hemisphere during
the last ice age, mainly near the edges of the ice packs and glaciers. They
went extinct between 10,000 and 20,000 years ago.
One of the best places to find mammoth remains today is in Russian Siberia.
Siberia today is a vast plain, mostly tundra, but also sparsely forested in
places. The northern fringe of it lies north of the Arctic Circle; the rest has
the seasonally cold climate and relatively long winters typical of continental
interiors and far northern latitudes. During the last ice age, half of Siberia
was covered by glaciers, and the remainder was prime mammoth habitat.
This past May, a baby female mammoth was found by a reindeer hunter. He was
understandably shocked when what he thought was a dead reindeer half buried in
snow turned out to be a small elephant. Fortunately, Russia has a scientific
establishment that is used to dealing with the occassional woolly mammoth
carcass.
Here’s the Yahoo News article I found about this:
http://news.yahoo.com/s/nm/20070711/ts_nm/russia_mammoth_dc_2
The carcass was taken to Salekhard, where mammoth experts from the Russian
Academy of Science’s Zoological Institute have been examining it. And where
they have made an exciting discovery:
…the fact the mammoth was so remarkably well-preserved — its shaggy
coat was gone but otherwise it looked as though it had only recently died –
meant it was a potential treasure trove for scientists.
“Such a unique skin condition protects all the internal organs from
modern microbes and micro-organisms … In terms of its future genetic,
molecular and microbiological studies, this is just an unprecedented
specimen.”
Mammoth skeletons are fairly common in northern latitudes of Europe, Asia,
and North America. Mammoth relatives, mastodons, are very common in Michigan,
where I came from originally. Frozen mammoth carcasses, while rarer, are still
discovered periodically. But to find genetic information in a fossil: that is
something truly extraordinary. Perhaps this new mammoth find will help shed
some light on the relation of mammoths to modern elephants.
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Birds of a Feather Swim Together
Some new fossils shed a bit of light on the history of penguins.
If you’ve been reading this blog regularly, then you’ll have noticed that I have two particular loves in the animal kingdom: birds, and fossils. This post combines them both.
There’s been a truly wonderful fossil find in Peru. The remains of not one, but two, new species of penguin have been discovered there.
You can read a good news article on the discovery here:
http://news.yahoo.com/s/livescience/20070625/sc_livescience/giantancientpenguinslikedithot
So what makes these fossils so interesting?
Well, for starters, the larger of the two new discoveries would have stood over five feet tall, and wighed more than 110 pounds. Most penguins today are less than 30 inches tall, and rarely weigh more than 15 pounds. Even today’s “giant” penguin, the King or Emporer penguin of Antarctica, is only two thirds the size of this fossil giant. This extinct penguin is, truly, significantly larger than modern species.
Second, both species were found in Peru, not far from the equator, in 30 million year old rocks. This puts them in a time and place with a much warmer climate than today. As the article notes:
The findings call into question the established idea that penguins evolved in high latitudes and didn’t waddle close to the equator until about 10 million years ago?long after Earth cooled significantly.
Thomas Henry Huxley, the famous 19th century exponent of evolution, once said that the finest theory can be killed by a single fact. Here are two facts, suggesting that perhaps penguins started out their evolutionary run with a much greater distribution than we thought. Remember: penguins like habitats, deep water and rocky coasts, that are not good for fossil preservation.
And were are penguins today? They are a modestly successful group of seabirds, widespread through the higher latitudes of the Southern Hemisphere. Again, from the article:
…17 penguin species inhabit the globe, ranging in size from the two-pound, 16-inch little blue penguin to the 84-pound, 4.3-foot Emperor penguin.
And while we think of penguins strictly as cold-weather birds, two species, the Humboldt penguin of modern Peru, and the Galapagos penguin, live year round in warmer climes.
A Perennial Favorite Animal
Another elusive giant squid has been found.
Ever since I was a little kid, and read 20,000 Leagues Under the Sea, I’ve been fascinated by the giant squid.
And why not? Here is an animal that can measure more than 25 feet long, weigh more than 600 pounds, and kill giant sperm whales. It’s inspired legends, from the ancient Greek Kraken to Norse sea serpents, and the best part of all is, it’s real.
I was browsing through some online news the other day, and found this article:
http://news.yahoo.com/s/nm/20070711/sc_nm/australia_squid_dc
Here is an excerpt:
One of the largest giant squid ever found has washed up on a remote Australian beach, sparking a race against time by scientists to examine the rarely seen deep-ocean creature.
The squid, the mantle or main body of which measured two-meters (6.5 feet) long, was found by a walker late on Tuesday … on the western coast of island state Tasmania.
So, how’d you like to find that the next time you go for a walk on the beach?
“Mmm, what a romantic morning, Honey.”
“It sure is. I just hope the sea monster doesn’t get us…”
Other than jokes, I am not sure what to say. Giant squid normally live at depths between 600 and 2300 feet. They are rare for the same reason as the Ceolacanth I blogged about earlier: if they come up to the surface, the difference in pressure, temperature, and light will kill them. No giant squid has ever been found alive in surface waters.
Which is why the Aussie scientists are rushing to examine this specimen. Squid in general tend to decay quickly once they die (remember that, the next time you order calamari), and giant squid especially so. A body that size will very quickly attract scavengers and predators who are always on the lookout for a free meal. As the article points out, the tentacles on this one are no longer intact.
I’m posting about this just for the sake of posting it. It’s always cool to see a childhood-favorite monster come alive.
What are the Facts and Theories of Evolution?
As I’ve been writing this blog, you’ve probably been noticing some common threads weaving in and out of various posts: the relationships between animal groups, the nature of evolution, and the modern evidence of evolution.
To start with, in any discussion of evolution, you need to define a theory. In popular usage, a theory is basically a “best guess” as to why something happened; in science, however, a theory is a well supported supposition, explaining observed facts.
The next definition you need is for evolution. In modern biology, evolution is simply the name given to the fact that species change over time, and that similar species are likely to be closely related genetically.
These two definitions make it clear that there is no one “theory of evolution.” Evolution is an observed fact; there are theories designed to explain the fact, and there is a great deal of debate among biologists about those theories.
So what are some of the theories which have been put out there to explain evolution? Well, I am not a biologist, but I do like the field and try to read up on it, so here is my take on some theories of evolution:
1) The most venerable, of course, is Darwin’s theory of natural selection. Darwin’s model describes how, when individual organisms act in their own best interest (defined as reproductive success; leaving the most surviving offspring), they will tend to pass favorable features on to succeeding generations. As a result, populations will change over time.
2) Theories of genetic contraints on development. These get complex. Basically, in a strictly Darwinian natural selection, organisms vary randomly, and the fortuitously best adapted will survive and reproduce. However, organisms are not truly random with respect to variation. As complex systems in their own right, organisms are constrained in how they can change by their genetic code and body structure. These constraints can guide the paths of evolution.
3) Punctuated Equilibrium is a theory about the pattern of evolution. It takes the fossil record literally, and predicts that gradual change is not to be expected. Rather, that species are in stasis for most of their history, and have bursts of evolutionary change at the beginning and end of stasis periods. These bursts are incredibly long by human standards, 10,000 to 100,000+ years, but minute specks of time compared to the 500 million year history of animal life on Earth.
As you can see, one fact, evolution, can spur people to develop numerous theories. These burgeoning theories do not mean that the fact is wrong; only that it is complex, with far reaching implications. A fact like evolution, which predicts that all life arose from a single common ancestory, meets that definition.
It’s Cicada Time
Bugs are everywhere. Oh joy.
Everyone in the Midwest knows by now, that it’s Cicada Time.
Cicadas are the famous insects that live underground for most of their lives, and only emerge every 17 years to mate, feed, and make a lot of noise, and die messily on the lawn, the sidewalk, the windshield of the car, etc, etc, etc…
Actually, that’s not quite accurate. There are several species of cicada, with varying emergence cylces. Some cycles are 5 years, some 7, some 9, and then there are the famous 13 and 17 year cicadas. You can see these as a child, and forget all about them until your twenties….
Our focus on their emergence cycle is really a sort of human-parochialism. Cicadas are not dormant while they are underground. They have several molts between the time they hatch and the time they emerge, and the intervening larval and nymphal stages feed, move around, grow, and interact with each other and with their environment. At the end of this multi-year growth period, the final molt occurs, and the adult insect (what we think of as a “cicada”) emerges from the ground, feeds on leaves, mates, lays eggs, and dies.
The multi-year cycle is most likely an evolutionary adaptation to avoiding predators. Cicadas are highly nutritious, and make excellent meals for blue jays, robins, crows, and rodents. None of these predators, however, can depend on cicadas for food, since they can only hunt them when they are above ground. And when the cicadas do emerge, they emerge in such numbers that the predators cannot possibly get them all.
So remember, no matter how much of a nuisance they are when they come out, cicadas’ lives are much longer than you normally think, and for the most part, they are completely unnoticed.
