In spite of high-profile stories on the International Space Station, global warming and erratic weather patterns, the past year has to be dubbed “the year of the biologist.”

The top science news story for the year 2000 is an easy call. It has to be the announcement in June that two rival groups of researchers had deciphered the human genome. The genome, a 6-foot coil of DNA nestled in the cell’s nucleus, is the blueprint from which all of the body’s characteristics are derived. Francis Collins of the publicly funded Human Genome Project and J. Craig Venter, founder of Celera Genomics, a biotech firm in Maryland, made the announcement at the White House with President Clinton.

DNA contains four organic bases, abbreviated A, C, T and G, whose arrangement dictates how the body’s protein is put together. Human DNA contains a little more than 3 billion of these bases in sequence and Venter said that Celera’s computers had to make more than 500 million trillion comparisons to work out the proper sequence. The next step will be to determine how segments of the sequence fit into individual genes and how variations lead to specific genetic disorders. This will take years but, once completed, will have an incalculable impact on the lives of future generations.

In what turned out to be a big year for genomic research, Celera Genomics, in conjunction with several academic laboratories, have sequenced the genome of the fruit fly and, as reported in the June 10, 2000, issue of Science News, University of California geneticist Gerald Rubin has determined that the 120 million base sequence is contained in roughly 14,000 genes. Finally, in what has been hailed as a major breakthrough in plant biology, the genome of a tiny plant called thale cress has been sequenced according to the Dec. 16, 2000, issue of Science News. Where all of this will lead is anybody’s guess but, as the Dec. 22, 2000, issue of Science states, “2000 was a banner year for deciphering the book of life.”

My vote for No. 2 in the science-news sweepstakes goes to the recent National Institutes of Heath ruling that human stem-cell research can proceed under certain restrictions. This is important from two perspectives. It will spur increased research in the use of stem cells to treat certain neurological disorders and spinal cord injuries, and it will almost certainly give new impetus to the debate over the ethics of biomedical research. No matter where one stands on any given aspect of this debate, such as the ethics of using fetal tissue or a right to genetic privacy, it is vital that it take place. As a harbinger of what could soon happen in the United States, the Oct. 19, 2000, issue of Nature reported that British insurance companies have been given the go-ahead to base insurance premiums on the results of genetic testing for Huntington’s and six other unnamed genetic degenerative diseases.

Third place goes to some troublesome, but little-noticed reports on environmental pollution. A wide range of drugs used by humans and animals are finding their way into the nation’s rivers, lakes, and even municipal water supplies. These include antibiotics, hormones, prescription drugs such as the cholesterol-lowering clofibric acid, and a host of others. According to an article in the April 1, 2000, issue of Science News, the concentrations are often high enough to alter the gender of fish and to find their way into household tap water after passing through treatment plants. Then there is the report that phthalates, a class of water-soluble plastics found in food wraps, nursing bottles and many other products, can cause reproductive abnormalities in children. These show up as premature breast development in girls while retarding sexual maturation in boys.

Finally a group of also-rans in no particular order: An iceberg the size of Connecticut splits from Antarctica’s Ross Ice Shelf. Pulses of light have been tracked at apparent speeds well in excess of the accepted speed of light said by Einstein to be sacrosanct. Work on the International Space Station is well under way but doubts remain as to its ultimate scientific, as opposed to political, value. New evidence has surfaced for the possible presence of water on Mars giving new energy to the hunt for life on the Red Planet. If I missed what you considered the top science story of 2000, drop me a line and it will be included in a future article.

Clair Wood taught chemistry and physics for more than 10 years at Eastern Maine Technical College in Bangor.