Download 16.3 Beyond Darwinian Theory

16.3 Beyond Darwinian Theory
I. Darwin’s Theory Updated
A. Discoveries since Darwin’s time in
genetics have been added to his evolution
theory of species.
B. 1st major advance was the rediscovery of
Mendel’s laws of heredity
C. Modern synthesis of evolutionary theory
1. Combined Darwin’s theory with fossils,
anatomy, genetics, etc.
1
II. Studying Evolution at All Scales
A. Microevolution
1. Refers to evolution as a change in the
genes of populations.
2. Five processes than can affect
microevolution.
a. Natural Selection
b. Migration – movement of individuals
into, out of, or between populations
c. Mate Choice – if mates are paired
up randomly than a random
assortment of genes will be passed
2
on
d. Mutation – can change the # & types
of alleles
e. Genetic Drift – random effects of
everyday life can cause differences
in gene frequencies
B. Macroevolution
1. refers to the appearance of new species
over time
2. There are six processes in which new
species evolve
a. Convergent evolution – environment
strongly directs evolution of several
species in different locations
3
b. Coevolution – Adaptations that
species have for one another
c. Adaptive Radiation – Over time
species may split into two or more
lines of descendants or lineages
d. Extinction – Self explanatory
e. Gradualism – many small changes
that build up gradually over a long
period of time
f. Punctuated Equilibrium – species
remain stable for long periods of time
& then sudden environmental
changes create new pressures
4
C. Speciation
1. the formation of new species as a result
of evolution.
2. Can begin with the separation of
populations of the same species.
a. ex- two squirrel populations
separated by the Rocky Mountains
5