A Sensory Quest: BBC Wonders of Life

Paramecium
Back in the very beginnings of my scientific education, I was taught the ‘MRS GREN’ code of life (movement, respiration, sensitivity, growth, reproduction, excretion and nutrition). Although quite rudimentary, this was a perfectly satisfactory way of distinguishing between things that were living, and things that were not.

The S in MRS GREN, sensitivity, stands for the ability of all living things to detect changes in their environment. To do this we use our senses, a characteristic dating back to virtually the beginning of life. Even simple, single celled organisms can sense their environment and respond to it.

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Porcupines show humans how design is done.

Firstly I apologise to my regular readers for not putting up any posts in the last few weeks (months!). My new job is going well, but as I’m sure you can all understand it has taken priority! But do not fear, I’m back, and I’m going to try my best to get posting regularly again!

When I moved to Cambridge I had a lot of ‘stuff’ I had accumulated, including two very prickly cacti. One of the thorns from the cacti got caught in my finger and, when I tried to pull it out it snapped, so it was stuck in my finger! Highly inconvenient to me, but it did get me thinking about animal and plant defences, as well as the pain they can cause!

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How did the Zebra get its stripes?

For centuries we have asked questions of evolution. Questions such as why does a Leopard have spots, how did a Camel get it’s hump or perhaps most famous of all: why is a Giraffe’s neck so long? A lot of the time people create “just-so” stories to answer these questions. For example, “it was favourable in terms of evolution by natural selection to be a Giraffe with a longer neck to reach higher branches”. When this theory was tested they found that Giraffes actually spend most their time foraging in low branches. Scientists now believe the long necks are used by males to fight each other for access to females to mate with. (The fact they can also reach higher into fruit bearing trees is an added bonus!) This is called necking. There are plenty of videos on YouTube if you are interested! Most just so stories have now been tested and more scientifically minded and testable hypotheses have been given to describe them. However there is one story that has been puzzling scientists until now: why does a Zebra have its stripes?

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Mosquitos – To kill or not to kill, that is the question.

The climate we live in today is one of change. There is a huge debate as to if that change is for the better or worse, but the fact remains the climate is changing. This is not a new phenomenon. The climate has radically changed since the beginning of life some 3.6-3.8 billion years ago. However, no single species has ever been directly responsible for changing the climate – until Homo sapiens rocked up. We are changing the climate so quickly evolution can’t keep up. This means many species are struggling to survive, leading to a significant number of species extinctions. We are very quick to jump to the needs of endangered species, particularly those that are beneficial to us. But what about the species we don’t like? What about mosquitos? How many times have you been on holiday and got a nasty bite, or been forced to religiously take anti-malaria tablets? Mosquitos are irritating disease spreaders, so why don’t we just get rid of them?

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