Homologous Legs Mini » Evolutionary Biology

Darwin’s Finches T-shirt design by ThinkGeek

naontiotami — Thu, 22 Jul 2010 05:09:10 +0000

Mmm-mmm, delicious geeky t-shirt designs, I can’t get enough of them. This one recently caught my eye over on ThinkGeek:

Here’s the description:

Sure, Darwin noticed the gradation in beak size of his “finches” in the Galápagos Islands, but he missed some big differences. For instance, we could have had significantly more 19th century science fiction if he’d noticed the Vampire Finch (Geospiza difficilis septentrionalis), which feeds on the blood of other birds. Our own team of ThinkGeek Junior Ornithological Knowledge Explorers has, consulting the excellent research conducted by Drs. Marvel and DeeCee, discovered six new variations also evolving from the Tiaris obscura:

a. super intelligence (for outsmarting Darwin)

b. super beak (for eating stale bread crusts tossed by tourists)

c. super eyes (for seeing through the garua)

d. super limbs (for outmaneuvering the Vampire Finch)

e. super speed (for visiting friends on the mainland)

f. super squawk (for broadcasting the latest volcanic activity)

Jonathan McLatchie, I am outraged, sir!

naontiotami — Wed, 30 Jun 2010 04:51:55 +0000

Of course, it was obvious that the Discovery Institute would get someone to blog about the responses that they’ve had to Casey Luskin’s recent posts about Haeckel’s embryos, but I never knew it would be such a vicious and personal attack against yours truly.

You see, Jonathan McLatchie has just posted a “response” to Nick Matzke and Matt Young, but my post about Haeckel and his embryos, which also responded to Casey, was not mentioned! I’m shocked and outraged. This is blatant discrimination. How dare they expel me from the discussion!

…

I’m not being entirely serious, come on, but it’s still telling that the Discovery Institute always chooses to go after the same targets (who, don’t get me wrong, make excellent points against what they have to say – The Panda’s Thumb is great) again and again. My guess is they do it so that they can build up an easy “us vs them” mentality, where you have the Discovery Institute and its allies on one side, and then the NCSE, The Panda’s Thumb and PZ Myers on the other – rebut those few “Darwinist” sources and you’ll seem to have neutralised all of your opposition in the blogosphere.

Well, that’s a highly dishonest approach, and I feel that they need to pull their socks up if they want to be seen as intellectually honest individuals. But, haha, who am I kidding? The Discovery Institute? Intellectually honest? The day will never come.

Excellent comment on the “Tetrapod Tracks” issue from The Panda’s Thumb

naontiotami — Sun, 10 Jan 2010 08:54:24 +0000

I think this comment on “Casey Luskin embarrasses himself again” on The Panda’s Thumb blog perfectly summarises the entire tetrapod-tracks-20-million-years-before-Tiktaalik-disproves-evolution argument that the Discovery Institute has recently been pushing around:

Leszek wrote:

So basically the “great minds” of creationism have come up with the argument:

If tetrapods evolved from Tiktaalik, why are there still tiktaaliks around [10 million years later]?

It seems to me I have heard this before somewhere.…

Oh Leszek, how very, very true that is. *chortle*

More evidence against a “metabolism first” origin of life

naontiotami — Sat, 09 Jan 2010 00:17:32 +0000

New research by Universitat Autònoma de Barcelona, published in the Proceedings of National Academy of Sciences, has revealed problems with origin of life hypothe ses that are based on metabolic systems developing first, as opposed to an RNA or DNA system.

The researchers found that compound genomes, or “composomes”, the basic unit of proto-life in metabolism-based hypotheses, are unable to undergo Darwinian evolution, putting serious doubt onto thoughts that they could foster the beginning of life on planet Earth.

However, this is just one study – more research needs to be done to confirm or deny these results.

Eight percent of the human genome is bornaviral in nature

naontiotami — Fri, 08 Jan 2010 23:39:35 +0000

Bornaviruses, a type of RNA virus that replicates inside the nucleus of host cells, has been found to be responsible for up to eight percent of the content of the human genome. Through endogenization, the virus’s DNA, retrotransposed from the RNA genome, has been integrated with our chromosomes over evolutionary time. Once the viral sequences are in the genome, they can be inherited through reproduction like any other part of the genome.

Due to the nature of bornavirus infections – they only infect neurons, the cells that comprise brain tissue – researchers have hypothesised that bornavirus genome integration could be the source of psychiatric disorders such as schizophrenia. A fascinating idea, but one that will have to be backed up with solid evidence in the future.

Even killer whales cannot escape the pull of evolution

naontiotami — Thu, 07 Jan 2010 11:26:04 +0000

Two kinds of killer whale have been found in UK waters, prompting evolutionary biologists to posit that the species of dolphin may be undergoing a speciation event.

The differences are fairly obvious – one kind, dubbed Type 1 had significant adult tooth wear, showing that they feed primarily by sucking up fish into their mouths, while Type 2 showed no wear at all. Type 2, on the other hand, seem to prey on other dolphins and small whales. Type 2 males also seem to be up to two meters larger than Type 1 males.

Evolution in action – an amazing thing.

Prions capable of evolution

naontiotami — Fri, 01 Jan 2010 08:41:34 +0000

Prions, the proteins responsible for various diseases including bovine spongiform encephalopathy (aka. mad-cow disease), have been found to able to evolve via mutation and natural selection just like traditional life-forms.

Even though by most measures prions are not living organisms – they are proteins with no genetic material – the Scripps Research Institute has found they can adapt to their environment and become more dangerous over time.

Charles Weissmann, the head of the study, had this to say:

“On the face of it, you have exactly the same process of mutation and adaptive change in prions as you see in viruses. This means that this pattern of Darwinian evolution appears to be universally active. In viruses, mutation is linked to changes in nucleic acid sequence that leads to resistance. Now, this adaptability has moved one level down- to prions and protein folding – and it’s clear that you do not need nucleic acid (DNA or RNA) for the process of evolution.”

Very interesting. It’ll be fun to see what creationists and intelligent design proponents such as the Discovery Institute have to say about this find.

(via BBC News) – (h/t to @dreadpiratemick on Twitter)

The evolution of koalas revealed

naontiotami — Fri, 18 Dec 2009 22:40:06 +0000

Continuing on with the “fossil skull revealing new insights into X’s evolution” line of news stories, skulls of two koala ancestors, Litokoala and Nimiokoala, have been analysed by Dr. Julien Louys from the University of New South Wales.

The analysis revealed that the mastication (chewing) apparatus of modern koalas, who subsist on a diet solely comprised of eucalyptus leaves, is much more specialised than the same apparatus in the ancestral species when compared with the distinction between the middle ears of both modern and ancestral koalas – in other words, there was more difference between the chewing mechanisms than the middle ears, suggesting that they evolved separately at different times.

You gotta love those Australian animals.

Fossil of seacow ancestor discovered

naontiotami — Thu, 17 Dec 2009 23:42:34 +0000

The skull of an ancestor of the modern-day seacow, which lived 48.6-372 million years ago, has been discovered in Madagascar. The location of the discovery may be a new fossil bed, one which may help unlock some of the evolutionary history of the country.

Professor Karen Samonds, the scientist who unearthed the find:

“The fossils of this ancient sea cow are unique in that it has a full set of relatively unspecialized teeth whereas modern sea cows have a reduced dentition specialized for eating sea grass, and most fossil species already show some degree of reduction. It may also be the first fully aquatic sea cow; confirmation will depend on recovering more of the skeleton, especially its limbs.”