August 2011 – Victoria Ellis

The sad truth about British indigenous species – not exotic or exciting and too familiar?

August 20, 2011 by Victoria Ellis

The sad truth about British indigenous species – not exotic or exciting and too familiar?

Those of you who have read my “About me” section will know that I am currently doing work experience at a local zoo on the Elephants and Big Cats section. The past two weeks have been excellent so far, with many experiences which I hope will stay with me forever. Working at the zoo, I have noticed the incredible number of “opportunities” visitors have to donate money to charities the zoo supports. There are literally collection boxes everywhere! Now don’t get me wrong, there are thousands of endangered species in the world and the sad truth is without the continual financial support of the public they probably will become extinct. However, I think we often forget about the less exotic species, found closer to home.

I was astonished to find that there are 10 species of animal indigenous to Britain that are on the brink of disappearing forever, including the cuckoo, red squirrel (see my second blog) and the iconic British hedgehog. Over the last 10 years the hedgehog population has declined 25% to 1 million. If this decline continues at the current rate, hedgehogs will be extinct in 15 years. A reduction in habitat is the main problem facing the hedgehog, resulting in sharing of their habitat with predatory badgers as well as humans in residential areas. In the residential areas, hedgehogs have to fight against pesticides killing their food (caterpillars and beetles), as well as rat poison, strimming and mowing. Unfortunately, it doesn’t stop there. An additional 50,000 hedgehogs on average are killed by motorists or drown in garden ponds.

As mentioned above hedgehogs are not the only species indigenous to Britain that are under threat. There has been a huge effort recently to understand the 60% decline in cuckoo populations over the last 25 years. The behaviour of these birds is well known in our own country but on return from their annual migration to Africa, there seems to be fewer birds than expected. Researchers decided to fit 5 birds with a 5 gram tracking system to see where and when the migrating cuckoos run into trouble. Currently all 5 birds are in Africa, 4 of which have crossed the Sahara heading south.

Saving endangered species has two key parts. Firstly researchers must work to understand the problems facing the animal in question, and then create a strategy to not only positively influence the animal’s population numbers, but also ensure no damage is caused to the animal’s ecosystem. Secondly, once the strategy is approved money must be injected to see the plan through. In terms of Britain’s situation this may be where the likes of the hedgehog and the cuckoo come stuck. The British public already donate a huge amount of money to charities supporting endangered animals outside the UK, but asking them to support British animals instead or as well as, in the current economic climate may prove too much to ask. I fear it may be true that it is the exotic and unfamiliar that will get the limited financial backing and in this case, that does not mean support towards Britain’s indigenous species. It is of course your decision but I urge you to think about the animals you are supporting and not forget the ones closer to home.

Blog 8 - Hedgehog vs Tiger — Hedgehog vs Tiger, which would you choose?

British Hedgehog Preservation Society – http://www.britishhedgehogs.org.uk

Cuckoo tracking website – Location via Google Maps of all 5 cuckoos and a link to a donation page – http://www.bto.org/science/migration/tracking-studies/cuckoo-tracking

Humans vs. our 3.7 million year old ancestor: Not so different after all?

August 14, 2011 by Victoria Ellis

Humans vs. our 3.7 million year old ancestor: Not so different after all?

I love my degree (Zoology), but if I had to choose a different degree which I think I would enjoy equally it would be Biological Anthropology, otherwise known as the physical development of the human species or more generally human evolution. I am not alone in my fascination for this subject. It is shared with many people from our own species, all trying to understand who, what, where and when we came from. The modern technological revolution has resulted in a huge leap forward in genetics and computer simulation which has increased our knowledge in this area astronomically. This allows scientists to refine, and/or recreate previously used methods in a hope to increase the accuracy of their conclusions.

A paper recently published in the Journal of the Royal Society has used new methodology to show that the first known fully bipedal hominin footprints are 3.7 million years old – 1.8 million years older than previously thought. The research was carried out by scientists at the Universities of Liverpool, Manchester and Bournemouth. The footprints, (discovered in Laetoli, Africa) are much more similar to a modern human than expected. Using computer simulation the gait of these hominins can be recreated, and that too is very similar to modern humans.

The method of using footprints as a way to visualise the individual that left them is relatively new one but has revolutionised our understanding of early bipedalism in hominins. First, computer software creates a 3D image of the foot which left the footprint, which is then compared to modern human footprints. The software can also show where the most pressure is applied when making the print. This relates to the posture of the individual and so can also be useful in visualising the print maker. All this information is then brought together to identify the most likely printmaker based on what we already know about the morphology of past hominins. In this case the 3.7 million year old footprints were made by a member of Australopithecus afarensis. It was previously thought that A. afarensis used the side of its foot to walk but the pressure points identified show that was not the case. This research shows that A. afarensis actually used it’s big toe to push off from the ground, much like a modern human. Furthermore the early hominin had a much more upright posture than previously thought and had a gait very similar to modern day humans.

It is widely accepted that A. afarensis is a direct ancestor of the Homo lineage, and therefore a direct ancestor of modern humans too. As I discussed in my previous blog, research is been carried out to try and decipher what it is that makes humans unique. It was long thought the answer was our big brains, which resulted in our upright posture, which was our great advantage. However this research shows that at the time when the hominin lineage developed a big brain (2.4-1.5 million years ago), hominins had already been walking upright for at least 1.5 million years. As a result this quest to know what it is that makes us unique is still left wide open. What is clear is that modern humans have a passion to know things, in particular to know about ourselves and what we came from. The advances in technology are allowing us to take further conclusions from the evidence available to us and to learn from it. There is after all that old cliché: how can you know yourself without first knowing where you came from.

Humans: not so unique, not so special? The case of the clever Mandrill.

August 1, 2011 by Victoria Ellis

Humans: not so unique, not so special? The case of the clever Mandrill.

Introduction

Not so long ago the world of science was very different. Leading scientists of their age believed in alchemy, a 6000 year old (flat) Earth and that DNA was unimportant. Another belief was that humans were superior to any other animal on the planet. It wasn’t until Charles Darwin presented his theory of natural selection in the 19^th Century that opinions began to change. As we all know, this theory made people think again about where or more importantly from what species originated and ultimately that humans are not so different from other animals.

Since that realisation, more evidence from genetics to behavioural studies has been gathered which further supports the theory. In the 1970s it was thought that humans were the only primates that used tools, but since then evidence of tool use and/or manipulation has been found in a number of primates including chimpanzees, gorillas, orangutans and capuchins. Current scientific thinking is to study these behaviours and see how they can help us understand the evolution of our own tool use behaviour.

Observation of tool use and modification for apparent hygiene purposes in a mandrill

A paper was published in May this year which describes the use of tools by alpha male mandrill monkey in captivity at Chester Zoo, England. To confirm the use of tools the mandrills were videoed over 252 hours, of which the alpha male demonstrated tool use 7 times. The tool use observed involved the alpha male picking up and studying wood chip and bark from the floor surface. The preferred wood chip and bark was then broken down into twigs and again into splinters. The splinters were then used to clean underneath the toenails of each foot. After a splinter broke, or had worn down too much, a new splinter was selected.

It is clear from this observation that this captive mandrill is able to identify, manipulate and use tools. As the behaviour was not a one off, it can be implied that the act was achieved intentionally. It is unlikely the mandrill is imitating a human it has seen behaving in this way due to the mandrill’s environment. But it is possible the mandrill was only able to develop this behaviour due to the extra time available as a result of not having to find food.

While it is obvious more studies, using different mandrills are required to further support this study, mandrills can now be considered as a tool using and modifying animal. The study also provides more evidence that it is not just the great apes that display tool use, but also other old world monkeys such as the capuchins and mandrills.

Final thoughts

A question that has been frequently asked about the human species is: what makes us so special? For a long time people thought it was our tool use, but with so much evidence to contradict that being our unique feature it seems unlikely. A relatively new theory presented by Professor Paul M. Bingham and Joanne Souza suggests that our uniqueness is our ability to demonstrate non-kin independent social cooperation. That is, our ability to form a culture, to socialise within that culture and to cooperate regardless of relatedness. Obviously this is and can only be a theory, and like any theory it is being tested, but it is gaining scientific backing.

This case is an example of how scientists do get some things wrong, even fundamental knowledge such as the shape of the earth or the origins of our species. What is important is the progression from one theory to another one, with better evidence supporting that new theory – otherwise known as the scientific method. This method is the foundation of science and with its continual use we can begin to understand some of the most fundamental questions facing science.