ABSTRACT
Is evolution a matter of survival of the fittest or survival of the most stable?
A. M. Waldrop
Recall from linear algebra that a map L : R2 → R2 is called a linear transformation if
1. L(U1 + U2) = L(U1) + L(U2) for U1, U2 ∈ R2
2. L(αU) = αL(U) for U ∈ R2 and α ∈ R. Moreover, it is always possible to represent f (with a given basis for R2) by
a matrix A. A typical example is
L
( x y
)
= ( ax+ by cx+ dy
)
which may be written in the form
L
( x y
)
= ( a b c d
)( x y
)
or L(U) = AU, (4.1)
where U = ( x y
)
and A = ( a b c d
)
.
