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Going ape offers better family tree
By Tina Hesman Saey
Comparing a newly compiled genetic
blueprint of a western lowland gorilla
named Kamilah with the blueprints of
humans and chimpanzees shows that
the three species didn’t make a clean
break when splitting from a common
ancestor millions of years ago.
Although humans are more closely
related to chimps across about 70 percent
of their genetic blueprints, or genomes,
about 15 percent of the human genome
bears a closer relationship to gorillas. An
international team reports the findings,
from the first gorilla genome to be deciphered, in the March 8 Nature.
A separate study of western chim-
panzees, published online March 15
in Science, also has implications for
understanding the human-chimp split.
The new work shows that humans and
chimps have different strategies for
shuffling their genetic decks before
dealing genes out to their offspring.
Neither humans nor chimps shuffle
genetic material randomly across the
genome. Instead, both species have
what are called hot spots, locations in
the genetic material where matching
sets of chromosomes recombine most
often, Gil McVean, a statistical geneticist
at the University of Oxford in England,
and colleagues report.
The genetic blueprint of a gorilla named
Kamilah (shown) reveals that about
15 percent of the human genome is
closer to that of gorillas than chimps.
of the genome with inactive genes.
Chimpanzees’ shuffling pattern is
similar to that seen in some previously
studied organisms, while the human
pattern is unusual, McVean says. In
humans, the location of recombination
hot spots is determined by where a protein called PRDM9 latches onto DNA,
but that protein doesn’t appear to be
the driving force for recombination in
chimps. “Everything points to humans
being the odd ones out,” he says.
Genes differ in
extrovert bees
Scouting behavior suggests
insects have personalities
By Rachel Ehrenberg
That honeybee lazily probing a flower
may actually be a stealth explorer,
genetically destined to seek adventure.
Bees who consistently explore new
environments for food have different
genetic activity in their brains
than their less-adventurous
genetic activity in their brains
than their less-adventurous
Honeybees that scout out
food show different gene
activity in the brain than
less-adventurous bees.
hive mates, scientists led by entomolo-gist Gene Robinson of the University of
Illinois at Urbana-Champaign report in
the March 9 Science.
The scientists placed a hive in an enclosure with a brightly colored feeder full of
sugar water and marked the bees that
visited. A few days later, the researchers added a new feeder to the enclosure,
were considered nonscouts. and added a different one in a new place.
Again, some of the bees discovered this
new feeder. The bees that
sidered scouts; bees that
ate only at the original feeder
were considered nonscouts.
The researchers then looked at what
genes were active in the brain tissue
of scouts and nonscouts. “We saw
massive differences in over 1,000 genes,”
says Robinson. Some of these genes
relate to the same molecular pathways
implicated in thrill-seeking in humans,
suggesting that evolution may use the
same genetic toolkit across species for
behavioral traits. And the work adds to
growing evidence that humans aren’t the
only species that has personalities.
“If you ask people if they think a squid
has personality, they usually say no,”
says psychologist Sam Gosling of the
University of Texas at Austin. But individual squid, and apparently bees, may
consistently seek new things. In animals,
scientists call that “novelty-seeking,”
while people who exhibit similar traits
get labels like “extrovert.”
FROM TOP: SAN DIEGO ZOO; COURTESY OF ZACHARY HUANG/ BEETOGRAPHY.COM
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