MATH AND THE ENVIRONMENT
What is ecology?
Ecology (also known as bionomics) is a branch of biology that deals with the abun-
dance and distribution of organisms in nature, as well as the relations between organ-
isms and their environment. It is an inherently quantitative science, with ecologists
using sophisticated mathematics and statistics to describe and predict patterns and
processes in nature.How is mathematicsused to describe population growthof organisms in a
certain environment?
In general, a certain population of organisms—from rabbits to humans—will grow
exponentially if it is left unchecked. That means that in a “perfect world” a popula-
tion’s rate of increase is constant. This can be seen in the following equations:- after 1 year P 0 (1 r)
- after 2 years P 0 (1 r)^2
- after 3 years P 0 (1 r)^3
...
318 • after nyears P 0 (1 r)n
How many bases are in a human’s genome sequence?
T
here’s a good reason why computers are so important to biologists working
on the human genome. The amount of data is staggering, and would take sci-
entists generations to analyze without the benefit of computers. For example, it
would take about 9.5 years to read out loud (without stopping) the three billion
bases in a person’s genome sequence. This is calculated on a reading rate of 10
bases per second, equaling 600 bases per minute, 36,000 bases per hour, 864,000
bases per day, and 315,360,000 bases per year.
One million bases (called a megabase and abbreviated Mb) of DNA sequence
data is roughly equivalent to one megabyte of computer data storage space.
Because the human genome is three billion base pairs long, three gigabytes of
computer data storage space are needed to store the entire genome. This
includes something called nucleotide sequence data only and does not include
other information that can be associated with sequence data. Because of such
numbers, scientists working on the human genome are grateful they have com-
puters on their side!