Genomic disorders

The human brain, in all its staggering complexity, is the product of evolution. It is a recent innovation – it probably appeared in its modern form only a few tens of thousands of years ago.

By understanding how the human brain evolved, researchers hope to identify the biological basis of the behaviours that set humans apart from other animals – such as language and art. Research may also shed light on the many conditions linked to abnormal brain function, such as depression, autism and schizophrenia.

Evolution is founded on the process of selection – successful organisms survive and reproduce, unsuccessful ones die off. How animals behave can influence how successful they are, so it is reasonable to assume that behaviours have been shaped by evolution.

However, the mechanisms of evolution operate at the level of genes, the units of inheritance. So we may look for behaviours that provide a selective advantage to an organism, but to understand how they evolved we have to look at genes.

Unfortunately, how genes shape behaviour is not well understood. Genes simply carry information, such as coding information for proteins. These are used to build a cell, cells are put together to create tissues and organs, including the brain, and the brain is the source of most of our behaviours. Throw in some environmental influences and it can be very hard to draw links between genetic changes and behaviour.

Despite this daunting complexity, researchers are beginning to make real progress in unravelling the mysteries of human brain evolution.

Genes and genomes

What genetic changes may have led to the evolution of the human brain?

Flies and worms

How simple ‘model’ organisms can shed light on the evolution of behaviour.

Birds: Bright and beautiful

Birds are surprisingly smart, particularly when it comes to food and sex.

Building a brain

How is a brain constructed and how has this changed during evolution?

Language and communication

What clues do genes provide to the evolution of language?

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Understanding the genetic basis of behaviour
Seth Grant 1.35 min - 7,393 kb
It is essential to understand the mechanisms that occur within the brain, the regions of the brain, the types of nerve cells and ultimately the biochemistry within those nerve cells. And not just the biochemistry but the nature of the genes that controls that biochemistry. Therefore the ambition is to understand all of the processes from the gene all the way through to behaviour, which is what we do in our genes to cognition programme. To achieve this integrated view, one needs to have methods that can be applied at each of the principle levels of analysis. Therefore one would want to study the behaviour of an animal and at the same time want to be able to study the genes. And clearly the best way to do that is to study organisms such as humans, also mice, and indeed flies and other animals, where there are mutations or defects in the genes and one can measure in the very same animals, the defects and changes in their behaviour. To fill the gap between behaviour and genes, we can then isolate proteins from the brain and study the biochemistry, the signaling pathways and the enzymes that change and we can also study the electrical properties of the nerve cells by recording from those nerve cells either directly in the brain or in nerve cells cultured in dishes. And by taking this multilevel approach we can fully understand how the product of a gene can ultimately participate in the mechanisms of behaviour.