Dr Alice Roberts: The Incredible Unlikeliness of Being

A Roberts. unlikeliness of being

About a month ago I started reading Prof Alice Roberts’ book ‘The Incredible Unlikeliness of Being’ and it certainly didn’t disappoint. I have seen many of Prof Roberts’ TV documentaries and have read one of her other books ‘The Incredible Human Journey’ and have always enjoyed their content. My own academic and personal interests include human evolution, the human body and subjects surrounding the natural sciences making Alice Roberts’ books and programmes deeply interesting.

I have meaning to read ‘The Incredible Unlikeliness of Being’ ever since I received the book last Christmas and I am very glad that I’ve finally got round to it. A large portion of the work published by Alice Roberts has surrounded the topic of human evolution and as that is the subject I studied as an undergraduate I was mostly familiar with the material and areas covered. However, her latest book goes back deeper into evolutionary history and discusses the evolutionary history of our bodies. This means looking at embryos, genes and the visible anatomy using the latest research in order to understand how we came to look like the way we do today.

Throughout the book there is amazing detail that is described in such a way that it is to understand, so even if you have a limited knowledge of anatomy you should be able to follow. There are also many illustrations, which were hand-drawn, that again assist to understand the processes and structures that are being discussed. Whilst reading this book I learnt so many things about our anatomy and our evolutionary history. Most of my knowledge surrounding evolution is focused on and around human evolution, with other primates and some other mammals for comparison but ‘The Incredible Unlikeliness of Being’ has definitely expanded my knowledge.

One thing that this book highlights for me is that we as human beings are not unique or incredibly special. We are a product of evolution and a great deal of luck that we even exist. For some this thought is terrifying and wrong – that we are special and that makes us better for it. I have totally the opposite opinion. The fact that we can see traits that give us a hint of our evolutionary history and that these traits can be seen in other organisms is amazing. However, from another point on view at a very individual level it is incredible that either you or me are here today. It is chance that a particular sperm met that particular egg to produce you and this story repeats itself at every level of our evolutionary history. The more I think about it more the mind boggles!

This is a great book that is well written and easy to both read and understand. I highly recommend it to anyone who has an interest in evolution, biology or anatomy.

 

A Look into Cat Genomics

Image of an Abyssinian cat. image taken from http://proxvost.info/ln/en/short-haired/abyssinian_cat.php

Image of an Abyssinian cat, the first to have their genome sequenced. Image taken from http://proxvost.info/ln/en/short-haired/abyssinian_cat.php

As a part of my Skull of the Month series I always try to find out a bit about the chosen animal’s evolutionary history. This is because I studied human evolution at university and want to broaden my knowledge of other animals. This month’s skull is the domestic cat, an animal I am familiar with in everyday terms but not on a scientific one.

Previously I have written about the domestic dog and their history. To be honest I already had a general idea about the dog’s past as I also have always had an interest in wolves. It is also evident that the domestication of dogs came about through hunting and guarding with human settlements.  The cat, however, is a completely different story. Of course I know that the domestic cat is related to the other big cats around the globe but that’s as far as it went and with regards to cat domestication I didn’t even know where to start! However, a quick search on Google Scholar identified the perfect article to start off with. This was a review article from Cell Press entitled ‘State of Cat Genomics’ by O’Brien et al. (2012). This article takes a look at some of the progresses made within the field of genomics relating to the domestic cat including how the genomes have been sequenced and what they can tell us about the evolutionary history and domestication of the humble cat.

The modern cat was selected as one of 24 mammals to have their entire genome sequenced in 2005 by the National Human Genome Research Institute. The first cat to have this done was an Abyssinian cat called Cinnamon. By examining genomes of other mammals advancement into human, and also animal, health can be made. Table 1. (p.269) in the article provides some examples of the used for cat genomes.

 In order to reconstruct the origins if the domestic cat a robust molecular phylogeny had to be made. To do this the 35 cat genes were selected and sequenced in all cat species. The earliest identified predecessor of cats lived in Europe during the Miocene and was Pseudaelurus andgave rise to the Asian ancestor of modern cats ~11 million years ago (Mya). The first split from this ancestor cat produced the Panthera genus (containing lions, tigers and leopards, around 10.8 Mya.  A second split in Asia produced more species which speciated and moved into South East Asia. A further split around 6-10 Mya produced an inter-continental migration into Africa. This was achieved by a fall in sea levels producing a land bridge across the Red Sea. This also occurred across the Bering Straits to Alaska permitting movement into these new continents. As sea levels raised these land bridges were lost which separated the continents allowing for evolution of new species of cat that we are familiar with today. During the Pliocene more migrations occurred between America and Asia and into South America as the sea levels continued to rise and fall over time.

Molecular phylogeny of Felidae. Image taken from article, fig. 2 p. 273.

Molecular phylogeny of Felidae. Image taken from article, fig. 2 p. 273.

 From the genetic data it has been established that the origins of cats was founded in Asia. However, where and when did the modern cat that is so familiar today come from? By conducting a phylogeographic study using a large data set of domestic and wildcats from Asia, Europe and Africa the evidence pointed to the Near East. It was found that a large proportion of domestic cats across the globe possess genotypes which are indistinguishable from classes that have been identified in subspecies of wildcats cats in the Near East. In addition to this a discreet population of wildcats was found in the Near East using an alternative analysis. This evidence suggests that the founding population for the world’s domestic cats came from this area.

 Aside from the genetic data archaeological remains also support the theory of the origins of cat domestication residing in the Near East. The remains for cats and humans were found together and dated to 9,500 years ago. This coincides with the first agricultural settlements in the Fertile Crescent, an area of fertile land between the Arabian desert and the mountains of Armenia.  These settlements also date to 10,000 years ago, providing compelling evidence that humans and cats were in the same place at the same time. 

 A theory as to why cat domestication arose is that the cats may have been used to farmers in the removal of rodents. It is known today that cats are sometimes bought and kept in order to rid mice and rats of land. However, in the late 18th, early 19th Century cats were started to be selectively bred to produce fancy breeds. This is in stark contrast to the domestic dog that was bred into a number of sizes and types to assist with hunting. Most importantly these cats can be traced back to those in the Near East. Interestingly all 68 breeds of the international Cat Association and the American Cat Fanciers can trace their origins to the Fertile Crescent and human civilisation. 

 From this one article I have already learnt so much more about the domestic cat. Their history is really interesting, and I bet that there even more to find out. It’s just a shame that they are considered to be the only group of the Felidae species that is not currently endangered or threatened. 

 

O’Brien, S. J., W. Johnson, et al. (2008). “State of cat genomics.” Trends in Genetics 24(6): 268-279.