Biology Week is an annual celebration of the biological sciences that aims to inspire and engage the public in the wonders of biology. The Society of Biology created this awareness day in 2012 to give everyone the chance to learn and appreciate biology, the science of the 21st century, through varied, nationwide events. Our belief that access to education and research changes lives for the better naturally supports the values behind Biology Week, and we are excited to be involved in it year on year.
Biology, as the study of living organisms, has an incredibly vast scope. We’ve identified some key figures from the last couple of centuries who traverse the range of biology: from physiology to biochemistry, sexology to zoology. You can read their stories by checking out our Biology Week 2014 gallery below. These biologists, in various different ways, have had a significant impact on the way we understand and interact with biology today. Whether they discovered dinosaurs or formed the foundations of genetic engineering, their stories have plenty to inspire, encourage, and inform us.
If you’d like to learn more about these key figures in biology, you can explore the resources available on our Biology Week page, or sign up to our e-alerts to stay one step ahead of the next big thing in biology.
Headline image credit: Marie Stopes in her laboratory, 1904, by Schnitzeljack. Public domain via Wikimedia Commons.
The post Biologists that changed the world appeared first on OUPblog.
Every month OUP editor and author Jonathan Crowe answers your science questions in the monthly SciWhys column. Got a burning question about science that you’d like answered? Just email it to us, and Jonathan will answer what he can.
Today: how do organisms develop?
By Jonathan Crowe
Each of our bodies is a mass of cells of varying types — from the brain cells that give us the power of thought, to the cardiac cells that form our heart and keep our blood circulating; from the lung cells that take in oxygen from the air around us, to the skin cells that envelop the organs and tissues that lie within. Regardless of their ultimate function, however, each of these cells has come from a single source — the fertilised egg. But how can the complexity and intricacy of a fully-functioning organism stem from such humble beginnings?
At heart, the growth of any organism relies on the repeated growth and division of cells. A cell grows, then splits into two. Each of those cells grows, then splits into two… and so the cycle continues. Before long, we’ve gone from having one cell to two, from two to four, and then to eight, to sixteen, etc. In fact, after ten ‘cycles’ we already have over 1000 cells. (We still have some way to go to generate the millions of cells that form an embryo, but you get the idea.)
Initially, the egg divides to from a hollow ball of cells. However, living creatures aren’t hollow. Instead, they have a clear inside and outside, with the inside usually comprising some kind of gut, which passes the length of the body, from mouth to anus. So how do we go from a hollow ball to something with a clear internal structure? Well, imagine holding a sponge ball between the fingers of two hands, and then pushing in the bottom of the ball with your thumbs. The bottom of the ball folds up and in, almost forming a ‘tunnel’ into the ball. Our hollow ball of cells does the same thing: the cells at the bottom of the hollow ball move up and inside to form a tunnel. These cells will go on to form the digestive tract, which (as our experience tells us) runs right through the inside of our bodies.
Shortly after, a strip of cells along the back of the ball of cells roll up to form a furrow. The cells forming this furrow will go on to form the nervous system, with the furrow itself becoming our spinal cord. And, again, this fits with our experience: our spinal cord does indeed run up and along our back.
The previous paragraphs reveal an important feature of the development of a living organism. It’s not just a question of having lots of cells: to have a fully-functioning organism, we need different cells to do different things – to have different functions. After all, our bodies would be quite useless (not to mention odd-looking) if we were composed entirely of lung cells. Instead, as a population of cells grows, it also clusters into groups with common functions, forming different tissues and different organs.
So how does a cell know what kind of cell it should become? At the simplest level, it depends on the cell’s location – its position in the embryo. But how can cells tell where they are? Do they have some kind of cellular GPS system? Actually, in a way they do. Just as the GPS feature of a mobile phone can tell us our location by picking up a signal from a satellite, cells can also receive signals from their surroundings, which vary according to their location. And, because cells at different positions in the embryo — top or bottom, front or back, left or right — receive different signals, they behave in different ways.
Our everyday experience tells us that our behaviour is modified by signals in the world around us – the most obvious example being the traffic lights that tell us when to stop or go when driving. In a cellular world,
This is the latest post in our regular OUPblog column SciWhys. Every month OUP editor and author Jonathan Crowe will be answering your science questions. Got a burning question about science that you’d like answered? Just email it to us, and Jonathan will answer what he can. Today: how do organisms evolve?
By Jonathan Crowe
The world around us has been in a state of constant change for millions of years: mountains have been thrust skywards as the plates that make up the Earth’s surface crash against each other; huge glaciers have sculpted valleys into the landscape; arid deserts have replaced fertile grasslands as rain patterns have changed. But the living organisms that populate this world are just as dynamic: as environments have changed, so too has the plethora of creatures inhabiting them. But how do creatures change to keep step with the world in which they live? The answer lies in the process of evolution.
Many organisms are uniquely suited to their environment: polar bears have layers of fur and fat to insulate them from the bitter Arctic cold; camels have hooves with broad leathery pads to enable them to walk on desert sand. These so-called adaptations – characteristics that tailor a creature to its environment – do not develop overnight: a giraffe that is moved to a savannah with unusually tall trees won’t suddenly grow a longer neck to be able to reach the far-away leaves. Instead, adaptations develop over many generations. This process of gradual change to make you better suited to your environment is called what’s called evolution.
So how does this change actually happen? In previous posts I’ve explored how the information in our genomes acts as the recipe for the cells, tissues and organs from which we’re constructed. If we are somehow changing to suit our environment, then our genes must be changing too. But there isn’t some mysterious process through which our genes ‘know’ how to change: if an organism finds its environment turning cold, its genome won’t magically change so that it now includes a new recipe for the growth of extra fur to keep it warm. Instead, the raw ‘fuel’ for genetic change is an entirely random process: the process of gene mutation.
In my last post, I considered how gene mutation alters the DNA sequence of a gene, and so alters the information stored by that gene. If you change a recipe when cooking, the end product will be different. And so it is with our genome: if the information stored in our genome – the recipe for our existence – changes, then we must change in some way too.
I mentioned above how the process of mutation is random. A mutation may be introduced when an incorrect DNA ‘letter’ is inserted into a growing chain as a chromosome is being copied: instead of manufacturing a stretch of DNA with the sequence ATTGCCT, an error may occur at the second position, to give AATGCCT. But it’s just as likely that an error could have been introduced at the sixth position instead of the second, with ATTGCCT becoming ATTGCGT. Such mutations are entirely down to chance.
And this is where we encounter something of a paradox. Though the mutations that occur in our genes to fuel the process of evolution do so at random, evolution itself is anything but random. So how can we reconcile this seeming conflict?
To answer this question, let’s imagine a population of sheep, all of whom have a woolly coat of similar thickness. Quite by chance, a gene in one of the sheep in the population picks up a mutation so that offspring of that sheep develop a slightly thicker coat. However, the thick-coated sheep is in a minority: most of the population carry the normal, non-mutated gene, and so have coats of normal thickness. Now, the sheep population live in a fairly tempera
