Friday, January 19, 2007


Biology and Palaeontology Qs & As has now moved to:

Ask A Biologist

Thanks to everyone who helped run this site. All the old posts can be found at AskABiologist so you can check out everything from this sit and loads of new features!

The new site still has a few bugs, so please give us some time to get them sorted out and to answer then new questions. See you there!

Friday, January 12, 2007

Bill, sent us this question....

As fossils come from many different strata and therefore comprise of different minerals to some others. In which part of the world would you find the 'best' ones with regards to ease of extraction and robustness (if those don't go together). What do you do with fragile ones?

As you rightly say, fossils are found in a great range of rock types. These rock types reflect the environments in which the fossils lived. For example, many dinosaur fossils are found in rocks that formed in coast and river plains, near where the dinosaurs lived, and where their bones could be easily buried and fossilised after the animal died.

As to where the 'best' fossils are found, it depends what you mean by 'best'. Some of the best-preserved fossils are found in rocks deposited in the deep-sea, for example the arthropods of the famous 'Burgess Shale'. Many complete, pristine fossils of insects and plants are found in ancient lake deposits, which also occasionally (and extremely rarely) preserve dinosaurs, pterosaurs, fish and frogs with 'soft tissues' preserved. These are the remains of the soft muscles and skin of the animals, which, in exceptional circumstances may be preserved along with the bones. These fossils are extremely rare and valuable. The photo is of an insect from the famous Messel group in Germany (about 40 million years old). It even preserves the original colour and irridesence of the beetle's body.

Most fossils are represented only by the bones and shells of the animal. How robust these fossils are depends largely on how well mineralised the remains are, and on how much disturbance the rock layers have been exposed to. Fragile bones can be hardened with glues and resins before being encased in plaster for extraction. There are many kinds of glues now available and fragile bones often require extensive work to support them. Sadly some still degenerate over time (especially those collected and repaired in the 1800s) and fossils are lost when they crumble away to nothing. Darren Naish reported on this situation in dinosaurs very recently in his blog here.

Thursday, January 04, 2007

Helen, sent us this....

I have read that in the past, the British Isles had a warm tropical climate, but I can't find more detailed information. I would like to know how the high latitude would have affected yearly cycles. Currently in the tropics seasons are more related to changes in rainfall, because day-lenght doesn't change much over a year, but in temperate zones seasons are related to day length and temperature.
How would a tropical climate be affected by changing day length? Would the winters have been colder than the summers? Would there be a massive amount of plant growth during the summer, and next to nothing in the limited daylight of winter? Could you point me towards resources which could give me more details?

There were several periods of warmer climate, the last one is about 1000 yrs ago and called the 'medieval warm period'.

Another period is in the middle Pliocene (ca. 3 Million Years Ago) when it was generally warmer than present, particularly at middle to high latitudes. It has been suggested that this period may represent an analogue for future climate change. Mechanisms that have been proposed to account for this warming are enhanced thermohaline circulation and/or greater concentrations of CO2 in the atmosphere. In the European and Mediterranean region the climate might have been warmer by 5 °C, wetter (by 400-1000 mm/yr), and less seasonal than present.

Some remarlable plant fossils were found along the British cliffs e.g. in the Bournemouth cliffs (which are notable for sands and clays of Eocene age). The fossil leaves seem to indicate that in Eocene times there was here an unusually warm environment even thought the palaeolatitude would normally suggest temperate rather tropical conditions .

The best link I found about the different periods is this one here.

The probelm of latitude is a completly different one, however. What is now the British Isles moved due to plate tectonics over the globe. Therefore it was once closer to the equator and the climate was therefore comparable to the tropics today.

For the determing factors of tropical climate this site here gives some good background.

Tuesday, January 02, 2007

Welcome to Biology & Palaeontology Questions and Answers!

This is a new service aimed at school children across the UK to help them get involved and interested in science. Collectively we are a group of professional biologists and biology workers (ecologists, museum curators, science writers and the like) who have got together to answer your questions about biology. Everything that you read here will be provided by real, working scientists who are experts in all aspects of biology. If you look below at our older posts (and back into the archives on the right) you will see some mini-biographies of many of the people who will be answering your questions.

Together, we are in a great position to answer your questions about biology, evolution, palaeontology, fossils, conservation and the environment. All you have to is click on the 'comments' button that appears at the bottom of this post (or any of the more recent posts), put in your first name, your age and your question, and then submit it. One of us will get back to you as soon as possible with an answer to your question. We will post up your question and our answer as a new post (like this one) on the main board so it is easy to find! We look forward to answering your questions, so give us some to answer!

We have been a bit slow over the last few weeks (it being Christmas and all) so aplologies for the delays in replying to the questions we have received. Normal service will resume shortly! We will be moving shortly to a new and much improved website! One of our Bloggers (Sarda Sahney) is working hard on the new site and you can take a look now. Not much is finished yet, so please bear with us.

This is all possble thanks to a very generous grant from the Palaeontological Association we are in the process of setting-up new pages. All will be revealed in due course, but we are still available for questions and everything that is on here will be transferred and archived in the new site. Hope to see you there soon!