Back from Leipzig

Well, the Congress is over and after a very long and very weird train ride, first there was someone who decided to jump in front of another train, which led do a 45 minute delay and after that, some Idiot decided it would be a good Idea to forget his suitcase within the train. And since some other Idiots decided to fly two airplanes into some buildings 10 years ago, a forgotten suitcase in a train is a case for the police. To make a long story short: I arrived in Mainz with a total delay of around two hours yesterday and was as exhausted as I was the days before.

The conference itself was great. I’ll have to admit that I thought I would be able to participate in the discussions there, but I saw pretty quickly that most of the other People there were on a completely different level then I was. This bothered me for quite some time, but then I realised that, as an undergraduate student, I don’t need to know all this stuff by now. So instead of showing off my tremendous knowledge (which I didn’t had) I started to enjoy listening to the stuff other people said and there was a lot of really interesting stuff going on.
In the end, the days in Leipzig were a very exhausting, intimidating and humbling experience, but I’m glad I went there. I saw how much stuff I still need to learn to really understand this field but I also realised that I really want to learn all this stuff. The last days gave me even more motivation to continue my studies so that maybe by the same time next year, I have something to present at the next ESHE Meeting, or somewhere else.
I’ll try to write about some of the stuff I heard in Leipzig within in the next weeks and there’s also this stuff about Australopithecus sediba which I wanted to write. I hope to get this Post done within this week.

At last I want to thank Anna Barros and Tracy Kivell who were both kind enough to answer a bunch of my questions and listened to some of my weirder thoughts during the Poster session on Friday.

Eric in Leipzig: Lessons from the first day

Scientific congresses are, especially if you're a little student a place to learn a lot of new stuff. So far I learned the following lessons:

1st Lesson: Don't be cheap.

I wanted to save 12,50€ for an addional night in a bed in a cheap hostel and decided to arrive at Leipzig the day the conference started. Only Problem: The conference started at 10am. This forced me to spend my night in a train, which lead to the nice fact, that I had around 1 hour of sleep in the night from Wednesday to Thursday.

2nd Lesson: Don't attend to a course on geometric morphometrics when you're deprived of sleep.

Lesson 1 leads directly to Lessen 2. I remember some of the stuff that was mentioned in this course yesterday but the most parts of it, and I think those were the more important parts, I forgot about five minutes after they were told.

3rd Lesson: Speak more english!

I think that I understand english fairly well, be it spoken or written. I think I'm also able to write in english in a at least partially understandable way. But my spoken english is abyssimmal. I have next to zero practice in speaking english and therefore my pronounciation is just bad and unsophistacated. And as you might guess, it's pretty hard to ask intelligent questions if hearing yourself speaking gives you nausea.

Well, those are the lessons I learned yesterday. I also learned something anthropological, but nothing of it is related to this congress and besides, I learn something about Anthropology almost all the time.

Let's see what interesting stuff happens today.

P.S.: I'm pretty sure, the english in this post isn't very good as well. But please keep in mind that it's around 7am and I'm still a little bit tired.

Sediba Post: Status report

I said I was going to write something about Australopithecus sediba, and believe it or not, I still intend to. However there were two things which mainly kept me from doing so within the last weeks:

1. Time:
In the last two weeks, my studies kept me from doing anything related to A. sediba other then reading the papers.

2. My Head:
To make things worse, I got a really good Idea what I can do with this fossil. There's something really neat which I wanted to demonstrate for quite a long time now, and I think the sediba fossils are the perfect objects for this little project. However I will need some time to prepare this post properly.

And at last, I'm about to go to Leipzig at Wednesday evening, where I will have the pleasure of walking around on a scientific congress until sunday. So don't expect something related to Australpithecus sediba until next week, but I might write something about this congress if I find something interesting.

Until then, why not read something about Australopithecus sediba at "Lawn Chair Anthropology"?

Australopithecus sediba: First (small) information dump

I didn't had enough time to completely dig through all the information towards Australipithecus sediba, but I intend to do so tomorrow. Until then, why not heare some words about Australopithecus sediba by some people who are far more competent then I am?

For example, you can read/hear an Interview with Lee Berger on the Science Podcast: Right here

Or you can read/hear an Interview with Lee Berger and Bernard Wood at NPR: Over there

The slump is over!

(well, at least kind of...)

Sometimes it's funny how things turn out in the end. Just as I'm about to finish the Assignment that ate up all my further interest in anything even remotely related to science so I could get started to get back into maintaining this Blog, Science released a bunch of Papers regarding Autralpoithecus sediba. This species was first announced last year, an announcement I somehow completely ignored back then, probably because the authors didn't put any effort into making some waky claims that could've set me up.
Anyway, I haven't looked much into the articles but I intend to do so within the next few days and report on what I think about them.

And since I have a little more time at my hands, I'll try to write about some of the other stuff that circles in head as well.

Speculation on Speciation

There is one topic which somehow touches almost every major debate in Paleoanthroplogy and this is the question about how speciation actually works. There were a lot of very smart people, who already wrote about this stuff, and I even read some of them. But a large proportion of what I’m going to say about this topic comes from my own thoughts on this topic. So if someone finds a mistake in my arguments, please let me know.


When it comes to speciation, there are basically two different opinions on how speciation could work. The first one is sometimes called “punctualistic” or “phylogenetic” and says that speciation usually results in a split in which the ancestral species splits into two different “offspring-species” (there is probably a more suitable term for it, I just can’t remember the English translation).

The second one is called “gradualistic” or “anagenetic” speciation and says that one species can, if there is enough time; evolve into another species without any form of splitting.

Now although there are many species concepts out there, the main criterion to recognize a species is, if their members are able to interbreed with other animals. This means that no matter what type of speciation process we propose, at some point during this process there has to be some kind of “breeding barrier” (once again, I’ve no Idea how to translate this term), be it either geografical, behavioural or otherwise.


Now let’s take a look on how this stuff actually works in case of a punctualistic speciation:

Exdample for a punctualistic speciation: Assume a Species "A" lives in a certain habitat "X". Now due to some reasons (e.g. a geological event), a barrier arises in said habitat. This barrier changes the enviroment on both of its sides and furthermore prevents the now separated populations of "A" to exchange their genes. With time, those two sperate populations will adapt to their new enviroments and will become two distinct species.

Ok, this was quite easy wasn't it? But how about gradualistic speciation? Her I'll have to admit that although I spent quite some time on this question, I just could come up with one scenario:

1. Let’s assume the species we’re looking at is restricted to one habitat

2. Let us further assume that all population of said species are able to exchange there genes with on another.

3. Now the habitat of said species changes and due to the wonder of natural selection the species adapts to those changes.

4. As time goes by the species within that habitat would differ significantly from the species we had before this process started, so that we could safely say that we have discovered a new species.

There is only one big problem with this model. If we assume a constant gene flow between the seperate populations of our example species, than this means that there never was any kind of mating barrier at any point in time. So how can we be sure that the species we witnessed at the end of that process isn’t able to interbreed with the species we observed before this whole thing started? Sure, we could assume that since both “forms”, as I might call them right now, are so different that they probably wouldn’t have interbred, if they would’ve lived at the same time.
This assumption is pretty similiar to the concept of a “Chrono-species” which defines species solely after their chronological appearances in the fossil record.
The Problem here is that we’re not able to test, whether or not, those species really weren’t able to interbreed. It is as always when we have to deal with extinct species, we simply can’t be sure about it. In the end the only safe thing we can say is that every model on the evolution of a certain species, which relies on a gradualistic model of speciation, is highly speculative.


There are two recent examples within Paleoanthropology where this Problem occurs. The first one is the possibility to draw a direct line from Australopithecus anamensis to Australopithecus afarensis (Kimbel et al. 2006, Haile-Selassie et al. 2010). The other one are the genetical evidences of interbreeding between modern Humans and Neandertals (Green et al. 2010) and modern Humans and those strange people from the Denisova Cave (Reich et al. 2010).
In both cases we have clues, if not even hard evidence in the second example, of constant gene flow between several populations over a long period of time.

The interesting question now, is what we should do with these findings. Should we just keep these different species and use some kind of dodgy chrono-species concept or should we lump all those different species into one or probably two?

I have to admit that, due to my education, I am a little bit biased towards the “lumping” part.

Right now I am not convinced that gradualistic speciation is possible, or to be more precise, that it is detectable by us. So the scientifically safer way for us right now, is to stay cleer of this concept unless we can find some way to test it.

Surely, the last word isn’t spoken on this one, and right now a can think of several flaws in my own argumentation, but I’m still convinced that it is the preferable way of thinking.


References:

Kimbel, W., et al. (2006). Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record Journal of Human Evolution, 51 (2), 134-152 DOI: 10.1016/j.jhevol.2006.02.003
Green, R., et al. (2010). A Draft Sequence of the Neandertal Genome Science, 328 (5979), 710-722 DOI: 10.1126/science.1188021
Haile-Selassie, Y., et al. (2009). New hominid fossils from Woranso-Mille (Central Afar, Ethiopia) and taxonomy of early Australopithecus American Journal of Physical Anthropology DOI: 10.1002/ajpa.21159
Reich D., et al. (2010). Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature, 468 (7327), 1053-60 PMID: 21179161

I'm still alive!

Unfortunately this isn’t a Post with any real content. In fact, it’s one of those “I’m just writing something to show that I still intend to write something”-like Posts.


The last weeks were pretty boring on when it came to interesting paeloanthropology-related news and those Posts I tried to write were in fact so bad, that I didn’t finish them. And at last, right now I’m desperately trying to finish my studies and unfortunately even this isn’t going as easy as it used to be. I even thought (and tried) to write about the stuff I’m working on right now, because it’s indeed quite interesting, but I just couldn’t find a suitable way to write about it, yet.


Anyways, things are looking a little bit brighter in the near future since I’m going to two conferences later this year. The first one is the meeting of the “European society for the study of human evolution”, which is held in Leipzig by the end of September. I have no idea about the exact program of this meeting, but I’m always excited to get in touch with other people from my own field, so I think it’s going to be pretty interesting.


The second one is the one I’m really looking forward though, partly because it’s held in Frankfurt which means that I can sleep at home and not in some cheap hostel. The topic is also quite interesting since it’s about ecology of the eocene and the early evolution of primates. Giving the fact that there was a lot of noise around Ida in the last two years I’m pretty sure, that this meeting won’t be very boring. I intend to write something about those meetings, be it in preparation for them, or while I attend them, so keep looking forward to it.
I’m still trying to write something within the next weeks though. I have some Ideas which could be suitable for interesting posts, so let’s hope that I can at least finish at least two of them.