This week’s podclast is the Geobloggers in the Pub episode. We talk about the KT boundary, including new research relating to it. Plus we lay into creationism in a pub-style chat fest.

Participants (links in brackets are Twitter feeds)

Chris - goodSchist (@yorrike)

Julia – The Ethical Palaeontologist (@morphosaurus)

Michael – Through the Sandglass

Dhiresh – A friend of mine and a geologist/geophysicist

The K-T Boundary and What Caused It

The paper we were discussing is by G. Keller et al. in Journal of the Geological Society, Vol. 166, 2009 [of London]. I can’t find the full name of the paper but I’ll keep looking.

Kim at All My Faults are Stress Related has a post on K-T extinction debates: cranky “skeptics” or reasonable science?

And the press release is available in various mass-media-filtered forms at Time, and the BBC.

Ethan Siegel’s Starts with a Bang has an article called What Wiped Out the Dinosaurs?, which is a superb run-through of the Chicxulub/KT impact. And you may want to read up on the Deccan Traps and how they relate to the KT extinction too. Also of interest, not because it explains the extinction, but because it’s another narrowly thought-out idea (or at least that’s how it’s been presented) is Insect Attack May Have Finished Off Dinosaurs which talks about the research from the book What Bugged the Dinosaurs?.

Creationism

You can look up Answers in Genesis yourself, as I won’t be linking to them, however the Talk.Origins Archive is a great place to look for basic questions and answers regarding the Evolution/Creationism debate.

Extra Note

The fossil of the seal ancestor is called the Pinniped, and information on the find can be found at the BBC and Eureka Alert.

Next Episode – Geoblogger in the Pub

We like to have a new episode of the podClast every fortnight. The next episode will be recorded at 1900 GMT on the 16th of May.

Contributing

If you’re keen to hear a specific topic talked about, or would like to join the discussion during the next episode, either leave a comment below or email chris [the at symbol] goodschist.com. You’ll probably also do well reading the details on joining the podclast. If you don’t have the time to join us but would like to contribute a 3-5 minute audio clip to the show simply record it, make sure it’s an mp3, and send it to the address above.

Credit

The intro and exit music was Roots Fi Cool by Burning Babylon.

Text Addresses

The post that accompanies this podcast can be found at http://www.goodschist.com/2009/05/07/the-podclast-episode-12/ or http://is.gd/xB3V and an archive of all podClasts can be found at http://www.goodschist.com/category/podclast/

Geologists normally have a slightly unfriendly attitude towards floral biota. It is, after all, one of the major obstacles normally preventing the viewing of outcrops. Geologists are also the people who look for, find and then think up fantastic new ways of mining petrological resources, like petroleum, natural gas and coal. The use of these products normally releases CO₂ and other greenhouse gases into the atmosphere, and unless this is your first interaction with the modern media in the last 20 years, I’m sure you’ve heard why this is problem. In a way, geologists have made it easier to use these products. But I’m hardly going to start laying blame for climate change, because this is a positive article. This is how I think geologists, scientists in general, and everyone else can help save the world. And it comes down to a single problem.

The Biggest Problem

The biggest problem with climate change and what’s causing it is very simple. The solution is also very easy (objectively). You literally don’t have to do anything. It’s a topic that no one (including the IPCC, overview here) seems to want to talk about. The main problem with climate change and the biggest problem currently facing the biosphere of the Earth is there are too many human beings. The solution is for humans to stop having so many children. It’s that simple. And I’m hardly the first to suggest it. With a universal one-child attitude and over a mere four or five of generations, we could quarter the human population (through absolutely non-violent means) to a more sustainable level. This would help to ensure the continuation of the species. Want to save humanity? Stop it from growing in size.

Suggesting this as a political goal or by the way of policy would be nothing short of political suicide, unless you’re at the helm of a totalitarian communist state (and even then, it doesn’t really work). The only way to achieve this is to make having one child the universal fashion (and keep it that way for a few centuries) and that somewhat runs against basic human nature.

The political problems surrounding that suggestion, have placed it firmly into the “too hard” box (no double entendre intended). But if you look at the problem objectively, the overpopulation of the planet is the root cause of the problem, and that’s one of the many fronts it should be tackled from (in a fair, humane manner, mind you. I’m a humanist after all and am most often in utter awe of some of humanity’s achievements and disgusted by its ill deeds).

Now my gushing is out of the way, I’ve often been interested in the evolution of Darwin’s immense beard. Here to hopefully inspire your own interest in the growth of this fascinating creature, I present Darwin’s beard through the ages (all images can be clicked and embiggened);

Every species but one (the first one) requires some sort of ancestor. Here we observe Darwin’s beard in early, primitive forms (left to right ages 7, 29 and 32). Not so much covering the chin, as framing it. Natural selection had obviously not required an adaptation requiring complete chin coverage in this environment, but the genesis is obvious.

At this stage of evolution (aged 45 and 51), the beard not so much as changes, but finds itself the in a changing environment where previous domination by head hair has come and gone. The time seems appropriate to fill the vacated niches. But how? Only natural selection will bear fruit on this mystery. A appearance of the clade known as “the crazy eyes”is brief and not well preserved in the fossil record.

Finally the last and most developed specimens of the Darwin beard (age 60 and 72). Here it makes its finest and most dominating appearance in its natural environment. Had suitable conditions continued, imagine the great evolutionary frontiers the mighty Darwin beard could have reached. Perhaps natural geographical isolation could have formed between hair of neck and hair of chin, resulting in speciation the likes of which the world has never seen.

Next year will mark both Darwin’s 200th birthday and the 150th anniversary of the first publication of The Origin of Species, so get to thinking about your celebrations.

But to be clear, what defines an epoch, an age, a period and era or an eon in the geological sense is reasonably arbitrary. There is nothing in particular one must consider as a marker between two periods. Time periods can be determined as the time when a particular large group of biota become extinct (like the P-T extinction event) or when there’s enough cooling for rocks to form and then for some of those rocks to still exist (like the Hadean-Archean boundary). A geological time is defined by geologists saying “that’s a good point right there because of this”, and nothing more. Brain at Clastic Detritus has an article expressing how annoyingly wrong a news article got this particular point.

In his latest article, The Anthropocene revisited, Andrew Alden takes another look at the concept of recognising the remarkable changes the human species has had on the geological record as a new geological epoch (Universe Today also has a good article up on this topic). The concept of the Anthropocene, as originally suggested by Nobel Prize-winning chemist Paul Crutzen in 2002 is discussed in a (freely available) GSA Journal paper entitled “Are we now living in the Anthropocene“, which I quote below;

A case can be made for its consideration as a formal epoch in that, since the start of the Industrial Revolution, Earth has endured changes sufficient to leave a global stratigraphic signature distinct from that of the Holocene or of previous Pleistocene interglacial phases, encompassing novel biotic, sedimentary, and geochemical change.
Zalasiewicz et. al., 2008

The current “sixth mass extinction” event we are causing started in the Holocene, the epoch that is defined as the 10,000 carbon years preceding 1950 (Zalasiewicz et. al. 2008, Wikipedia). This was the end of the Younger Dryas, the name given to the last ice age, and saw the beginning of the widespread extinction of mega fauna such as the Mammoth and the last Saber Tooth Tiger species. This, much like the extinction event at the Cretaceous-Tertiary boundary, began and continued slowly (in human terms) until a single event established it as a true geological boundary (and I’ve discussed this particular point before). It was a slow process. It began slowly (say, over a period like 10,000 years), and then ended suddenly (over a few months, but a few decades is basically the same in geological terms).

Though establishing a new epoch is probably best in terms of scientific enquiry, it would make the dawn of human domination of the Earth (the Holocene) a separate epoch from the widespread changes that domination brought with it. And if you consider the human phenomenon as a single natural process, it may make more sense to consider the beginning, duration and end as a single time period. And not to put too finer point on it, I think the amount of change currently occurring is so dramatic that establishing a new epoch maybe underplaying it. Should we begin to consider the establishment of a new Period once we can no longer sustain ourselves to cause as much change as we are currently? That being said, I’m in favour of considering everything since a yet-to-be decided point (and by point, I mean a very precise, slightly un-geological point, like new years eve 1850), as a new epoch, even if it does make the Holocene the shortest geological epoch ever. To be fair, I’m more interested in pre-Hadean events than the latter parts of the Quaternary.

References

• Zalasiewicz J, Williams M, Smith A, Barry TL, Coe AL, et al. (2008) Are we now living in the Anthropocene. GSA Today: Vol. 18, No. 2 pp. 4–8