Page 35 - DRAFT_LTMVol11No3no4of4#50-51-10pt.indd

ture…”

A GENUINE HYBRID
It looks like it was put together from a bird,
a reptile and a mammal: the duck-billed
platypus. Now an international team of re-
searchers has decrypted the genome of the
strange quadruped. “The fascinating mix-
ture of properties in the genome gives us a
number of indications as to how the genet-
ic traits of all mammals function and how
they have developed,” explains project co-
ordinator Richard Wilson of Washington
University in St. Louis, Missouri, in the
journal Nature. For biologists, the platy-
pus is unequivocally a mammal, because
the females raise their young on milk.
However, a monotreme (a mammal that
lays eggs instead of birthing live young)
has a cell makeup that corresponds with
the platypus’ appearance: it shares 82 per-
cent of its genetic material with humans,
mice, opossums, and birds. The remaining
18 percent is exclusive to the strange crea-
ture. For instance, its sex chromosomes
are unique: while mam-mals generally
have two sex chromosomes, platypuses
have ten. Monotremes split off from the
evolutionary line of today’s mammals
more than 166 million years ago. “At rst
glance, the platypus looks like an evolu-
tionary accident, but its genome will help
us understand the biology of mammals,”
says Francis Collins, director of the US
National Human Genome Research In-sti-
tute that has provided most of the funding
for the platypus project.
34 Legendary Times Magazine Vol. 11, No. 3 & 4 of 4 Vol. 11, No. 1 & 2 of 4 Legvendary Times Magazine 35