2008-11-19

Still here, still biting...

Not a pygmy tarsier; just a common one

Remember the "Gremlins", that were hyped during the early 90's? They were a cuddly and nice mogwai until you gave them water, fed them after midnight or exposed them to sunlight; then they started to clone themselves (groovy!) and became evil little bastards. This movie goes under the genre "comedy-horror" but we who weren't even ten when we saw it for the first time may have missed the "comedy" part. Either way, our parents probably told us that the gremlins weren't for real. This time, our parents were a bit wrong. Because deep in the wild of the Indonesian island of Sulawesi, scientists have re-discovered the pygmy tarsier, which is a gremlin look-a-like. They have been thought to be extinct for a while (last note of their presence where back in 1921), so most likely they are not able to clone themselves (aren't we all suprised). In addition, they live in a very moist habitat with fog all around at all times and appearently, they are not very cuddly because the scientist that found them got bit. Maybee it's the water that made them evil. Or not. BUT they do have something in common with other horror movies, the Exorcist namely. You know when the pea-soup-vomiting-possesed-girl Regan spins her head around 360 degrees? The pygmy tarsier are able to do halv of that (180 degrees, that is...in case your head isn't working today). Very impressive!
Source:

2008-11-12

Some general jibberish from a late-afternoon-tired mind

This will be a highly monologuic post, at least more than the previous ones. I came across this article today. In short, some researchers have found that women in all ages tend to like male faces that's more "testosteronized" than the opposite and that women in all fertile ages tend to deride female faces that are percieved as "pretty".
The good old female chauvinist pig in me immediately started to find flaws in the protocol of this experiment, such as using "attractive" as a general definition while I would say that this is a feature of high variance depending on whom is the judge. But then, the biology nerd in me started referring to nature: if all other mammals are allowed to have differences between the sexes and differences depending on their developmental status, environment etc. why should that not account for us as well?
It's a strong but stupid urge that almost all of us possess; i.e. the urge to take sides. But do we really have to do it in every single case that we come across? In this case, humans are definitely driven by our biology BUT as with all other living things (perhaps even more) we are highly dependent on environmental factors. You are born with the ability to be scared of dogs, but if you never encounter a dog behaving badly you'll never develop this feature. In addition, depending on whether you meet a angry dog when you're 3 or 30 years old the result may vary quite differently.
So, back to the faces-study. The thing is, I can relate to not liking "pretty" girls, or at least finding exuses not to feel entusiastic about their presence whenever someone else is talking about them. But is it nessecary so that I was born destined to feel this way when I began my fertile age all the way to menopause? Could it not be the environment that I'm born into that has formed the perfect settings for this behaviour to appear? Many factors could affect this, such as seeing how much attention these "pretty" ones get's from the opposite sex, or hearing how older females talks bad about other females. This does not mean that it's an innate behaviour.
What I do think that these types of studies could be good for is to make us take a step away from ourselves and see how we react. Thereby we can become more aware about the personalit(y/ies) that we have derived from the thousands possibilities present for us at birth. And we could try to stop behaviour that is not necessarily helping us in the society we have today. In a naive way, I believe by doing so, we might be closer to a nicer world. At least a world without cat fights.

2008-11-07

Born to be what?

We're all mutants. Now, I de-glorified all Marvel comics heros/villains that posess some kind of extrordinary gift due to being a "mutant". Well, it's not that remarkable in the real world. You won't gain any cool abilities by exposing yourself to nuclear waste, except the ability to grow aggressive tumors in your body (otherwise, imagine what the flora and fauna around Chernobyl would look like at this time). Still, mutations occur all the time; in us and around us. By using the different mechanisms, that causes mutations, in the laboratory we may see glimpses of how nature could work.

In all animals, fungi and plants there are a group of genes called HOX-genes. These dictates the development from a single cell to the multicellular being that we become. Think of them as "on and off" buttons that can be connected in a huge network, giving thousands of possibilities for combining the signals. In simple words, the different combinations of HOX-genes determines the orientation of the future body, i.e. where the head should be, the legs and so on, as well as growing wings instead of an arm. This means that a small change in the combinations directs the developing body to a completely different structure than "normal". Usually, the consequences are so severe that the fetus is spontaniously aborted, but not all developmental disturbances are lethal.

The fruit fly Drosophila melanogaster have been studied to the core when it comes to the HOX-genes. By disturbing the pattern of expression of these genes, either with mutations or environmental factors (such as chemicals) a fly with antennae instead of eyes develops, or a fly with two thoraxes (see pictures further down for both). In mice you can disturb the development by turning "on" some of the HOX-genes way too much so that the new born mouse has no hair at all. So it's not as simple as just having a genome with all you need to build a being. The genome must be extremely fine-tuned in order to have all limbs in the correct places!








Sources:

2008-11-06

When I come around

I tend to dwell a lot on everything that concerns being human. I mean, what combinations of minor and major evolutionary processes have led us to this character state defined as a Homo sapiens? Things like this can easily keep my nights sleepless. You know the saying if a tree falls in the forest and no one's around to see or hear it, did it ever occur at all? If you say no, then did the world really exist before your first memory? Even better: did the world exist before the one and only "I think therefore I am" species (i.e. us) came along?


If you leave out philosophy and creation myths that place humans in the center, then yeah, there was something here before us. Actually, there were a lot of things here before us. Some, like liverworth are still here today but more species that you could ever imagine have walked and inherited the earth in thousands (or millions!) of years before us, until some cryptic event made them head towards extinction. If you dig around in the earth's crust you may come across some fossils, but we will never ever be able to know all the creatures that have existed (or that will exist in the last million years of this planet, but that's another question).

Predating the waters of the Cambrian period was a strange little being named Opabinia regalis, belonging to a group of animals that have no decendants living today. The fossil record claims that it was up to 7 cm long, had five eyes and a really remarkable feeding part of its body (which makes me think of the offspring of a trilobite, elephant and a vacuum cleaner). The Cambrian period flourished with life forms in many, many versions but this period ended with the greatest mass extintion ever, leaving behind a fraction of species that later evolved into the various life forms we are today.


I may add that the fossil record is based on fewer than twenty fossils. Now, think about a present species that's fairly abundant in our world and have been so for a couple of hundred thousand years. Imagine that only a fraction of these were fossilised and only 15 of these were discovered by some future creature that has a bias for investigating the world's history. Will that say anything about all the other species that exist today? Not really... More fossils of other species might give more but we will never know it all. And that's what's keeping me up at night. Maybe it's a weird extension of being a control freak, but it really bugs me to know that I will never know how things have been before I came around.


Sources:
Evolution. An introduction (Stephen C. Stearns and Rolf F. Hoekstra). Second edition.