55 Music Concourse Dr.
Golden Gate Park
San Francisco CA
94118
415.379.8000
Regular Hours:

Daily

9:30 am – 5:00 pm

Sunday

11:00 am – 5:00 pm
Members' Hours:

Tuesday

8:30 – 9:30 am

Sunday

10:00 – 11:00 am
Closures
Notices

Please note: The Academy will be closing at 3:00 pm on 10/24 (final entry at 2:00 pm). We apologize for any inconvenience.

Parking and traffic in Golden Gate Park will be congested the weekend of Oct. 3–5. Save $3 on Academy admission when you take public transportation.

March 8, 2011

Long View Study No. 14 (Bdelloid Rotifers 1-5)

lv-study014-bdelloid-rotifers1-5-0028-greybkgrnd-500x657

The subject of this assemblage is bdelloid rotifers, tiny transparent animals found in
moist environments worldwide, including Antarctica. These fascinating invertebrates
were described in a chapter of Aurora Australis, the book printed by Shackleton’s
Nimrod crew in the cold, dark Antarctic winter of 1908.

The chapter’s author, the expedition’s biologist James Murray, titles his essay “Life
Under Difficulties” which refers not to the hardships endured by the men as he points
out, but “…rather to some of our very humble fellow-creatures, animals quite micro-
scopic in size, which are able to live under conditions which seem to us extremely
unfavourable.”

Murray goes on to describe the bdelloids’ resistance to damage (because of their size), endurance of drought (by entering a state of dormancy), and their tolerance to extreme heat and cold “…which promises to shed much light on the limits of temperature at
which life is possible on the earth.”

Indeed it did. But there was more to come. A hundred years on, scientists learned that these creatures are the planet’s most radiation-resistant animals—more so even than
the hardy tardigrades (a.k.a. ‘water bears.’) They also know now that bdelloid rotifers reproduce asexually, challenging the assumption that sex is necessary for the diversification of species (over 450 species in this case).

Most intriguing is that these animals have evolved and thrived over millions of years through the special ability to pick foreign DNA up from the environment and incorporate
it into their genomes. The new material comes from sources such as as bacteria, fungi, plants, even semi-digested food, and gets into the cells that will become eggs.

Murray wrote about bdelloid eggs but he never knew they were products of ‘horizontal gene transfer.’ He surely would have marveled that this process — common to bacteria — should also apply to his beloved Bdelloidea. Their ability to evolve this way is believed to
be unique in the animal kingdom.

Somewhat along the lines of finding foreign genes to build with, I used scavenged
material to create the specimens here. Wood, hardware, thread, paper, and graphite combine to depict Claria, a parasitic (fam. Clariaidae); Collotheca (fam. Collothecidae); Abrochta (fam. Philodinavidae); Balatro (fam. Dicranophoridae); and Keratella (fam. Brachionidae); a set of bdelloids chosen for its array of physical features.


Filed under: Studies — mbartalos @ 10:02 pm

No Comments »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a comment


Academy Blogroll