Wrestling with a


Dr Karin Meyer

When Karin Meyer began her PhD studies in the early 1980s, her task was to estimate these genetic parameters for milk production of dairy cows.  It quickly became evident that a restricted

maximum likelihood (REML) analysis was the method of choice as it accounted for potential selection bias.  This was a pivotal turning point in the field.  At that time there was no software available to do the kind of analysis she wanted to do, so she had to write her own.  By the completion of her PhD, and after the work was published, fellow researchers asked for a copy of the software used. This was the beginning of a career dominated by development of methods for REML analyses and the corresponding software. The first program which was targeted at the use by others and widely distributed was called DFREML, with the acronym standing for Derivative­Free REML.  Karin has been working with AGBU since 1990 and in this time she has contributed to much of the software that they have produced.

Over the years there have been big changes to software, the computing environment and complexity of analyses feasible.  One of the great changes came in the mid-80's with the move from using a sire model, where each record of an animal was assigned to reflect the breeding value of its sire, to an animal model where each animal's genetic merit is considered in its own right.  This allowed information from all types of relatives to be used simultaneously, yielding conceptually simpler analyses which made more efficient use of the data.  DFREML was capable of fitting the animal model.

The REML program was taken up by fellow researchers in the days when email was only beginning to be available.  Its popularity spread through word of mouth at meetings and conferences.  DFREML was distributed until 2005 then, with advances in technological capacity, Karin wrote a new, more modern program - WOMBAT - which was released in 2006 and

replaced DFREML.  WOMBAT offered additional features and considerably faster execution times, and has been made freely available for download from an AGBU web page for the last 15 years.  Today its capabilities include parallel processing and analyses incorporating genomic information.  It has had quite a number of downloads and has accumulated over 1000 citations in scientific publications, which shows its considerable impact.  Nowadays there are equivalents, including some which require a licence fee.  Wombat is free and does come with a manual and

a large suite of worked examples that show how to set up analyses and what should come out of them.  Learning how to use WOMBAT is often a process of reading the manual, finding a closely related one of the examples provided and working through it, and going back to the manual again.

There are two significant user groups for WOMBAT. One is researchers in countries where there is limited money to buy a commercial version of REML, or where they are running small data, and simpler analyses.  Some of these countries are just starting what is now the standard in the developed world and WOMBAT enables them to use this modern method with freely available software. And, importantly, it enables them to publish their research in refereed journals. So research in those places has been impacted, and of course this research, using the gold standard,

is then available for uptake in industry.

WOMBAT has been used world-wide - some of the countries include the Indian sub-continent, Iran, Thailand, and others in east and west Africa. Another user­ group of the program is by groups which don't do enough of this sort of analyses to warrant getting a commercial licence, but the approach remains important for their work. While developed for animal breeding applications, WOMBAT has also found use for research in fields like evolutionary biology, plant breeding and human genetics. Throughout the world in the field of Animal Breeding, Karin's research and her software, first DFREML, and now WOMBAT have become icons. Many scientists in the field today will have benefited from Karin's programs and directions at some point in their career.