Bios 101 PM Biology of Populations and Communities. Dr. Alan Molumby [email protected] 6-2994 3084 SEL Office Hours MF 9, W at 11, or by appointment. What is Out There?. Reading: Freeman Chps. 1, 50 and 55. Biology is the study of life, but what is life?.
What is Out There?
Reading: Freeman Chps. 1, 50 and 55
Question: Which of the following are inherent properties of living things?
B) Sexual Reproduction
C) Need for an Energy Source
E) A and C
Above is a chalcidoid, named and described,
Below are microbes from a Greenland glacier,
no formal description yet
This is what
we have described
note the large number
From E.O Wilson’s Biodiversity
This figure is fairly old, the numbers of described species
In each group have increased, but the proportions have remained
Clicker Question: Which of the following taxonomic groups has the LARGEST proportion of UNDESCRIBED species?
D) BeetlesE) Bats
This “five kingdom” scheme of classification replaced the old animal kingdom vs. plant kingdom scheme in the 1970’s. It is an excellent grouping of organisms based on their characteristics, but it does not reflect evolution very well.
Modern methods of sequencing
DNA, and a modern approach
to systematics allows a greater
understanding of the true
“tree of life”
The tree on the left, based upon
ribosomal RNA, which is very
endicates that there are three major
“domains” of living things.
The prokaryote archaea are closer
To eukaryotes than the bacteria.
Among the delta proteobacteria are the myxobacteria, interesting gliding bacteria that produce “fruiting bodies” under conditions of starvation.
Myxobacteria live in the soil, and “glide” along solid surfaces via a polysaccharide slime.
Although we know very little about them, the archaea are some of the most abundant, and important, organisms on the planet.
The group is very ancient-some bear a striking resemblance to fossils dated at more than two billion years old and many exploit ecological niches that were probably more important billions of years ago.
Though the majority live in ordinary habitats, the group includes many exptremophiles.
methanogens-live in anerobic conditions and break down methane
extreme thermophiles-live in incredibly hot environments
extreme halophiles-live in extremely salty environments
From Baldauf, SL Science, 2003, Jun 13 1703-6
EO Wilson’s Biodiversity again
Habitats for Other Organisms.
Many individuals of
a single species
are called a biological
Populations of organisms tend
to assemble into
Question: Which of the following organisms is NOT a eukaryote?