What genetic changes make us human?

By Grant Jacobs 22/07/2011

Katherine Pollard sets her aim at about 2:05 into the presentation: ’we want to pinpoint the parts of the human genome that are most different […] between humans and chimps, or other primates, and try to link these to human-specific biology.’

She talks about work by her research group finding the portions of the human genome that make us human, compared to extant species closely related to us.

Her talk has excellent slides and interesting tidbits, introducing, for example, some specific difference between humans and chimpanzees. The talk is directed at a general audience, although it will be harder going for many in the second half.

One reason it appeals to me is that it introduces a simplified version of some of the thinking that people in my field–bioinformatics, or computational biology–use in comparing genes or genomes from different organisms.

I’ve added a few words below the video that some might want to read before viewing the video; those that just want to plunge on in, here it is:

Genes code for molecules that ’do’ things in the cell, functional RNAs and proteins. Genes are ‘read’ by copying the message specified by the gene into a messenger RNA, which is then either used as a functional RNA or translated into a protein. Copying the message of a gene into messenger RNA is a process called transcription. This transcription process is started and controlled by proteins (and RNAs) that assemble onto particular small regions of the DNA around the genes they control. The DNA regions that these assemblies bind to are known as regulatory regions, because they regulate the expression (transcription) of genes.

What Pollard’s research group found–what she shows in her talk–falls in with others’ work showing that when species that are fairly similar are compared, many of the differences in their genomes that affect function are in regions outside of the portion coding for function RNAs or protein, in neighbouring regions that affect how the genes are used. That is the changes are frequently in the regulatory regions rather than the genes themselves.

In effect, when comparing fairly similar species, genes are building blocks that re more-or-less the same that can be re-used in different ways to different effect through alterations in the regulatory regions that control the use of the genes.

These changes in regulatory regions affect where in the body a gene is used, what chemical signals that the gene might respond to (to become active, or be shut down) and so on.

The video I’ve shown is one of many genetics-related videos offered by UCtelevision (University of California Television). I’ve offered one that I hope might appeal to a wider audience that might may deserve a little more exposure. It’s also a little shorter than some of others!

Feel free to ask questions.


Caveat: obviously my account is over-simiplified and generalised – it’s aimed to provide a general context of what she says, rather than details.

As some who is hard-of-hearing (deaf), it’s great to see how they have the speaker under light and not standing between the audience and the screen.

Other genetics-related articles on Code for life:

Take a summer studentship in Dunedin, New Zealand

Autism — looking for parent-of-origin effects

Doggie ERVs

Tracking disease and human migration through genetics

The inheritance of face recognition (should you blame your parents if you can’t recognise faces?)

Boney lumps, linkage analysis and whole genome sequencing

Temperature-induced hearing loss