DEEP ROOTS Analysis of the Mnemiopsis leidyi comb jelly's genome suggests it sits at the base of the tree of animal life.
COURTESY OF STEFAN SIEBERT/BROWN UNIV.
Scientists continue to decode the genetic blueprints of the planet’s myriad flora and fauna — both alive and long dead — shedding light on biology, evolution and disease. Highlights from the year include:
1. Comb jellies
A genomic analysis of comb jellies confirmed that the squishy marine predators are the new oldest animals, bumping the much simpler sea sponges from the base of the animal evolutionary tree (SN Online: 12/12/13; SN: 5/18/13, p. 20).
2. Ancient horse
The oldest genome yet sequenced came from a horse’s foot bone dating to between 780,000 and 560,000 years ago that was excavated in Canada’s Yukon. The feat revealed that horse ancestors originated 2 million years earlier than previously thought (SN: 7/27/13, p. 5).
3. Big cats
Genome sequencing of a Siberian tiger, Bengal tiger, African lion, white African lion and snow leopard identified genes behind the carnivores’ ferocious metabolism and powerful pouncing skills (SN: 10/19/13, p. 6).
4. Duck
The mallard duck genome gave researchers clues about how flu viruses that can infect humans develop in waterfowl.
5. Spruce
With nearly seven times the DNA of the human genome, the Norway spruce tree has the largest genome yet decoded (SN Online: 5/22/13).
6. Coelacanth
The prehistoric-looking, lobe-finned fish’s genome revealed that it is not the closest living relative to land-traversing tetrapods — lungfish take that title (SN: 5/18/13, p. 18).
