The chicken or egg problem

A recent argument with a friend made me realise, that I should make a note about the so called “chicken or egg” or also called “hen or egg” problem. 

In short: what was there first? Did a first egg emerge which let a first chicken hatch? Or was there a first chicken which laid the first egg? [1]

Maybe you think this is a stupid question? Yes, it is. And we were not even actually talking about this primarily back then. But we got into the issue somehow anyway, probably helped by the pub environment we were in at the time

However, my friend was sure that the only logical solution must be that the egg came first. He is not alone with this assumption since an expert group also ruled that the egg came first [2]. However, I replied that this is possible but no necessarily so, and since I came across a posting on the web the other day, claiming the same, I felt it is time to clarify [3].

 

First off: how to define a chicken?

What is a chicken? Where does the proto-chicken end and the modern chicken as we know it start? Domestication has led to today’s chicken. So we would have to assume that our great grandfathers are responsible for the chicken as we know it. 

Genetic research has indicated that the modern chicken is a cross of two wild species. Since there are many different types of domesticated chicken today the question is not easily addressed. However, let us assume that we take one subtype of the modern chicken. We would have to agree on which traits we want to include in our definition. Not few geneticists agree that this is a ludicrous task and that you simply cannot give a tight definition of the modern chicken.

Despite these difficulties, let us assume we could agree on a clear cut definition. Then we would assume that there must have been one pre-chicken who lacked at least one protein coding gene or gene-function of the modern chicken (also here we run into trouble if we would consider single nucleotide polymorphisms without effect on the aminoacid sequence as differences- but let’s not pick nits now [4]). 

We do know that mutations which are relevant for being passed on to subsequent generations do only occur in gametes, i.e. the male or female cells that are merged during fertilisation (egg or sperm cells). Mutations here occur due to cross-over events of the chromosomes but also due to mutations caused by random processes or mutation enhancing agents (like chemicals or radiation).

In this case clearly we would have an egg at some point which is the product of a sperm and an egg-cell which have produced the exact genetic information that we have agreed on to constitute a chicken.

This follows the assumption that we accept the definition:

- the first egg to carry the complete genetic (DNA) information of a chicken we accept as chicken egg

Then the egg comes before the chicken!

 

Chicken egg or no chicken egg?

You may wonder why I said, “[if] we accept the definition”; what other definition could there be for a chicken egg? Let us look at what an egg contains. 

The inner part of the egg contains the genetic information for the production of a new chicken, but it also contains some organelles, liquids and plenty of other stuff. Similarly to mammal eggs (including human) there also is the cell membrane that contains the mothers’ proteins and lipids. In the case of a chicken egg there is a hard calcified part additionally protecting the egg.

These proteins are coded by the nucleus. If the last mutation we were waiting for in order to see the first chicken-DNA to be completed occurred in a membrane protein, the egg we are talking about (containing complete chicken-DNA) would not have exclusively chicken proteins in its membranes.

Considering the calcified outer shell of the chicken we can safely assume that the structure changed with evolution. More precisely, the chicken shell developed from softer predecessors to the modern hard shell structure. So even worse; if we would (only as a brain-game of course, since we know that the wild type birds chicken derive from have hard shell eggs already) assume that the last and final mutation making a modern chicken happened in a protein controlling aspects of shell production, the first egg to contain chicken DNA was not a chicken egg. 

Exaggerating to make the point more transparent, one could imagine a gel-like egg that looks nothing like a chicken egg, but more like a soft reptile of fish egg. From this proto-egg a chicken would hatch which would then lay the first generation of chicken eggs.

Again: the first egg to carry all the nuclear genetic info to produce a chicken would not necessarily carry all proteins necessary to fulfil the definition of a proper chicken egg. Only the second generation of eggs would carry all chicken proteins and would be a proper chicken egg.

So, then we would have to define:

- the first chicken egg to be laid has to be laid by a chicken. 

The chicken comes before the egg!

 

Solving the mystery

Without knowledge of the exact definition the question of what came first: chicken or egg, cannot be answered (as so often definition is all, isn’t it?).

If one runs with the definition mentioned above, i.e. one is content to call anything an egg, that lets a chicken hatch (even if it is purple, cube-shaped and with spikes on its surface) then the egg came first.

If you insist that an egg has to contain all the ingredients of a chicken (not only the chicken DNA) then the chicken might have come first. Again: this is not necessarily the case but a fair possibility!

It all depends. And I guess it is clear that there are many philosophical attempts to answer the riddle out there. However, I wanted to answer the biological basis here. And I feel that chicken and eggs are primarily a biological problem to be solved.

The philosophical answers mostly come to the conclusion that the egg came first [3]. But I am not sure that philosophers necessarily know about DNA, mitochondria, ribosome, calcification and membrane proteins, to name only a few aspects one should be aware of.

 

Conclusion

It is more likely that the egg came first, which may be why “experts” have decided that the egg came first [2]. However, it would surprise me if they had not addressed the above thoughts and I would be curious to hear what they had to say about it.

However, the question itself is so extremely flawed in terms of its exact definition that it has to be treated rather theoretical of course. Admittedly, following our assumption that we would manage to define it in terms of genetics, the chance that some crucial gene for egg production was the “last gene” in the process of the chicken development is very small. This may be the simple reason the “experts” think the egg came first.

I would like to have you leave from this page keeping in mind that depending on our definition in combination with the right circumstances the chicken might have been there before the egg! And maybe next time you have the discussion coming up you can send them here

 

 

 

References

1) http://en.wikipedia.org/wiki/Chicken-and-egg_problem

2) http://www.guardian.co.uk/science/2006/may/26/uknews

3) http://www.eecs.harvard.edu/~cduan/writings/ckvsegg.shtml

4) http://en.wikipedia.org/wiki/Single_nucleotide_polymorphism

When to go where

I often have stumbled upon discussion forums where people were wondering when they should go to certain regions. When it comes to my planning you will see that my time in south-east Asia could have been chosen more wisely when considering that it is going to rainy season still in September. However, I am going to visit a friend and therefore was limited in my planning. 

However, in case you are about planning to go anywhere and you are not sure when to go there are of course plenty of resources on the net to help you. Here are some of the pages I used:

 

German:

http://www.theglobetrotter.de/weltreise/weltreise/planung/reisezeit.html#inseln

http://www.auswaertiges-amt.de/diplo/de/LaenderReiseinformationen.jsp

http://www.ipicture.de/daten/wetter_panama.html

 

English:

http://www.travel-climate.com/

http://www.bbc.co.uk/weather/world/city_guides/city.shtml?tt=TT004270

http://www.lonelyplanet.com/

 

South-East-Asia

Regarding the places where I am planning to go I would recommend to be in Thailand before July (later in the south) or later than September/October. Similarly for the Cambodia, Vietnam and Laos region. Rainy season does not necessarily mean that it rains every day or non-stop of course. However, between July and October you may get into some trouble when travelling minor roads by car or bus.

 

India

Northern India seems to be either insanely hot and rainy or hot and insanely dry. However, a good idea seems to be to  go there between October and February (less rain and not so hot) but not after February (getting hotter and June to September is rainy season). This is why I chose to be there in October/November. [http://www.world66.com/asia/southasia/india/delhi/lib/climate]

 

South- and Central America

Roughly places north of a line between Rio de Janeiro and La Paz can be visited most times of the year, while south of this line the weather can get a bit chill in winter time (around July to October). Especially southernmost place is Argentina and Chile can only comfortably be visited in summer time (around December to March). Hence I chose to take a flight down to Brazil once I arrive in the USA. I am going to be there in December and first make my way down south.

However, also high plateau regions in Bolivia, Chile and Peru can be quite cold at night even in summer from what I understand. In northernmost regions of South America (e.g. Ecuador, Colombia and Venezuela) temperatures are not the problem, but there is a rainy season starting in December and you might want to avoid this time.

 

Central and North America

It seems that regions in central America should be avoided before end of December and after May. Though the further north you get the later you can consider travelling there. Hence Guatemala and southern Mexico seem to be pleasant in May and June, when I am thinking of arriving there.

In Mexico summer can naturally get really hot, which is why you might not want to travel in July and August. The north of the US on the other hand (and Canada of course) are easiest to be explored in summertime, i.e. roughly June-August. New York gets really cold in winter time occasionally and Canada is interesting only for the hardiest of winter freaks from November to March. That is why I will attempt to be there in Spring (May/ June) before I go back to the lovely European summertime…

Vaccinations, visas, insurance and packing the right stuff

Now the tickets are bought, except the last ones of course for my return to Europe. So I am highly flexible to change plans and maybe even throw in a couple of weeks, months or years of work somewhere

Some of the important topics before taking the first flight are obviously things like visa and vaccination and money.

 

Visas

When it comes to visas the situation is highly dependable on your nationality. Even if you are a citizen of the EU it does not mean that all regulations apply equally. E.g. when travelling to Morocco lately I had to wait in line at the airport in order to get a stamp into my passport and before that I had to fill out some kind of visa application. On the other hand, french citizens do not need to have that and travel almost as if they never had left France.

If you are German the Auswärtiges Amt [1] is your best bett in order to get info on where you need to have what type of visa. I strongly recommend you to take care of that as soon as possible. Due to sometimes rather long waiting times of up to 4 weeks you should start 2 months ahead of your trip and add an extra months for every destination that demands  proper visa. 

Obviously that is if you do not life around the corner of the embassy of these nations or their consulates. But be aware that not all consulates issue holiday visas!

When I tried to get my visa for India by mail here in Spain where I am at the moment it turned out to be somewhat unnerving. I called after the usual processing time was over and was informed that they had not received the full amount of money from me which was why they had not even started to process my application. They did claim to have left a two messages on my mobile phone’s voice-box. However, my voice-box is not even activated, so that was just bull****. Be highly cautious with these things as it can screw with your whole planning. In my case, I was so early with everything that I got my visa still well in time…

When travelling to the US you should also be cautious, as there are new regulations [2, 3] for travellers starting January 2009. Then you will have to register online, well before you intend entering the USA by plane (now you will just have to fill out a card on the plane).

When it comes to south east Asia you won’t need a visa for the main hub Bangkok. However, Cambodia, Vietnam and Laos do demand a tourist visa. While you can easily get the visa for Cambodia online [4] you can get those visas e.g. in Bangkok while you explore the city for some days. I will get the visas for Vietnam and possibly for Laos in Cambodia, while I travel around there.

For south America you will not need a visa if you are an EU citizen. Similarly for central America (and Mexico) no visa is needed. However, beware that going to Cuba still is a different story. You should check with your local embassy. I did not get one in the end and took Cuba off my list for now. However, as I understand you have to provide them with info where you will stay and things like that. So it demands some planning ahead it seems.

 

Vaccinations

When it comes to vaccination you should not forget that this is not something that is up to you entirely. Depending where you travel and where you have been just before that you will need certain vaccinations. Mostly stuff you should have at home as well anyway, but especially yellow fever is needed and evidence of a recent vaccination has to be produced at the border of some nations. Else you are going to be on the next plane going back to where you came from again.

Check with you GP and take care of it at least 2 months before your trip. Some vaccinations will demand 3 shots over 1 or two months time in order to give you the desired protection. Also because in my experience especially yellow fever gave me some adverse effects. I felt like having a flu for a couple of days. So do it in time so you are fine and fit for your trip.

 

Packing thoughts

Of course that depends where you go and what you are planning to do. If you go scuba diving you may want to have some of the equipment with you, or if you intend to do a lot of hiking you want to have decent hiking boots for it. However, if you are like me and you are mostly in for the cultural sites and beach relaxation in between you are planning for light packing.

I intend to have one cargo pants and one jeans with me. If you are the hiking type you obviously would avoid such pants and would rather go for a more water rejecting and quick drying material. I will have two pairs of jeans shorts and a couple of beach-/running shorts. Underware does not take too much space and I prefer to take some more, so I reduce the need for washing to less than once a week, so I will have 10 sets of underware. I will need two short sleeved shirts and one long sleeved shirt. For some occassions you may want to have one that looks neat. May it be for going to a dinner or sorting things out with some goverment agency or the police after some trouble: looking neat comes in handy at times.

More important maybe than clothes (which can so easily be bought in most of the cities you will travel to) are the small things like mosquito net, decent repellents, recreational and hiking equipment, rain protection, books in you language, drugs you need, including your malaria medication and things like that. Things that may be harder to get where you go.

When it comes to malaria medication I will for obvious reasons (maintenance of my liver and mental health) not be able to take malaria prevention medication for the whole time. So I will instead have a dose of stand-by medication with me which I will need to take when I get symptoms and then I would have to look for the next hospital.

 

Documents

One thing I would definitely recommend is to scan tickets, passports, tan-lists of your bank, visas etc and put them on a password protected server on the internet. In case things get stolen it is much easier to get around and get replacements with these copies.

 

Insurance

If you plan to travel for more than six weeks you have to have a special insurance. Do not get fooled into buying an insurance “valid for one year” without checking how much time of that year you are allowed to travel. There are many of these inexpensive options, however, in most cases you can use this insurance repeatedly within a year but never for a trip longer than lasting six weeks.

Hence you need to look out for other options adjusted to the special needs of round the world travellers. The least expensive and concomitantly most suitable insurance for me comes form Axa [5]. One other thing you should be cautious about is, that some of these insurances do not cover you when staying in the USA or certain other regions of the world. In case of Axa there is a coverage for the USA but only up to a certain time. 

 

Money

I am going to take my EC-card and on credit card with me. I am not sure yet if I take traveller cheques with me. Since I got an account with DKB, a German internet bank, especially for this trip this might do the job. They offer you free cash withdrawing at any ATM world wide. In case of loss or theft you are merely responsible of up to 50€ before you report the loss.

I was gonna take a card from my Spanish bank too, as a backup, but I am not sure if I do that. The more stuff you have the more you can lose. But I will see how that goes.

All in all I can recommend DKB so far. The account is for free and you even get interest rates for money you have on their account. If you put it on the visa-card account you get almost 5% interest rates!

 

The list

To summarize:

Clothes

• 6-10 T-shirts
• 6-10 Underpants
• 5-7 pairs of socks
• 2 long trousers
• 2 short trousers
• 2-3 shorts for the beach or sport
• Sunhat or cap
• 1-2 short sleeved shirts
• 1-2 long sleeved shirts
• Sarong or similar cloth
• Sandals
• Sports shoes
• (or Hiking boots)
• Light summer shoes
• One large, one smaller towel
• Rain Jacket
• Sweater
• Light Jacket (to be combined with sweater/ rain jacket in cold regions)

Gadgets and equipment

• Guide book for you first destination
• Note-block and pens
• and/or notebook (I got an eee PC for the trip)
• iPod for music
• mobile phone
• chargers for everything
• money belt
• mosquito net
• bug repellent
• drugs you need regularly (e.g. migraine medication in my case)
• Anti malaria drugs
• Band aids and gaze
• sleeping bag
• sleeping bag inlay (a linen inlay you can use in hot countries)
• Books for recreational reading
• Sun screen
• Sun glasses
• Hat for sun protection

Documents/ Money

• Tickets
• Passport
• Visas
• Credit card(s)
• Traveller cheques
• If you have: student ID, Youth hostel membership card(s) etc.

 

 

1) http://www.auswaertiges-amt.de/diplo/de/LaenderReiseinformationen.jsp

2) http://german.germany.usembassy.gov/germany-ger/visa/vwinfo.html

3) http://www.cbp.gov/xp/cgov/travel/id_visa/esta/

4) http://evisa.mfaic.gov.kh/

5) http://www.roundtheworldinsurance.co.uk/